Tesis sobre el tema "Oncorhynchus kisutch"

This study addressed the hypothesis that coho salmon (Oncorhynchus kisutch) learn and remember the odours of their natal environment. During one or more of the embryo, alevin and early fry (first 14 d) stages, fish were exposed to the artificial odorant morpholine, natural odorants generated by conspecifics, or creek water. After an interval of at least 1 month the preference of fry for an odorant was tested in a Y-maze and compared to that of naive fry. Increased preference was interpreted as recognition. Fish exposed during any or all of the embryo, alevin, or early fry stages showed greater preference for morpholine than naive fish when tested 54-125 d after exposure. In addition, previously exposed fish responded to morpholine with greater heart rate reduction (another measure of recognition) than naive fish in tests 477-532 d after exposure. Exposure to the odour of similarly-aged members of another family of the same population during the alevin stage, and to that of a second family during the early fry stage resulted in increased preference for the alevin-stage odour by one of four test groups, for the fry-stage odour by another group, and for both odours by a third group, in Y-maze tests conducted at least 32 d after exposure. Subsequent experiments revealed preference to be an insensitive measure of recognition because it is greatly influenced by odour concentration and possibly other odour characteristics which differ between families. Members of the Quinsam River population exposed throughout the embryo, alevin, and early fry stages to the odour of similarly-aged members either the Big Qualicum River or Puntledge River populations each preferred the familiar odour when tested 69-79 d after exposure. In addition to familiarity, preference among population-odours was found to be influenced by quantity of odour. Quinsam, Big Qualicum, and Puntledge fish each preferred water conditioned by faeces of members of their own population over blank water and in one of two experiments over water conditioned by faeces of non-population members, suggesting that at least some of the odorants mediating intraspecific discriminations are present in faeces. Exposure to creek water for a 1 month period centered around swimup did not result in greater preference than that shown by naive fish for creek water over well water or either of two river waters in tests performed at least 58 d after exposure. It is concluded that coho form long-term memories of at least some artificial and natural odours in early life and that learning is not restricted to a brief critical period of development.
Science, Faculty of
Zoology, Department of
Graduate

Coho salmon (Oncorhynchus kisutch) from six hatcheries operated by the Canadian Department of Fisheries and Oceans Salmonid Enhancement Project, were reared in a common facility and then subjected to a series of standardized challenge tests. Results suggest that there are genetically based differences in the response to stressful challenges among stocks of coho salmon from southern British Columbia. The challenge tests were: saltwater (30ppt); saltwater and an increase in temperature (30ppt and 4°C); high pH (9.4 and 10.0); low pH (3.55, 3.65, 3.75 and 4.1); thermal tolerance (1°C/h); and handling (30s netting). The measured parameters were plasma sodium and chloride ion concentrations for the saline and pH challenges, time to dysfunction in the thermal tolerance challenge and plasma glucose concentration in the handling challenge. No differences among stocks were found in responses to the high pH and thermal tolerance challenges. The Chehalis River stock had the smallest plasma ion increase in salt water but showed the largest plasma ion decrease in acidic waters. In some of the low pH challenges the Tenderfoot Creek stock showed less plasma ion loss than other stocks. The stock from Eagle River had the lowest plasma glucose concentration increase during handling challenges. The combined saltwater and temperature increase challenge demonstrated the cumulative effect that stressors can have. Sampling associated with the handling challenges revealed a diurnal fluctuation in resting plasma glucose concentrations. The low pH and handling challenges showed that stock performance and the magnitude of the response observed varied with rearing conditions. Although there was some variation in the magnitude of the stock response to challenges between the two rearing conditions used, differences among stocks were consistent. When the response to all challenges were assembled into a relative challenge response profile (or performance profile), each stock was unique.
Land and Food Systems, Faculty of
Graduate

Tesis para optar al Grado de Magíster en Ciencias de la Acuicultura
Se entregan los parámetros genéticos de heredabilidad, correlaciones genéticas, y ganancia genética estimados para peso alevín, peso smolt y peso cosecha de dos líneas, año par e impar, de salmón Coho (Oncorhynchus kisutch), a partir de seis y cuatro generaciones respectivamente, del programa de reproducción de un núcleo comercial, en Chiloé, Región de Los Lagos. Se estima el nivel de consanguinidad alcanzado para cada línea en las cinco generaciones. La metodología utilizada considera el desove de reproductores individualizados, la incubación de ovas y desarrollo inicial de alevines en unidades segregadas por cada familia generada, marcaje individual de ejemplares juveniles y crecimiento en comunidad, con muestreos periódicos de peso corporal. La metodología de evaluación para la estimación de los parámetros genéticos fue el ‘modelo animal’ y los softwares Pedigree Viewer y MTDFREML.

The effects of inhibiting estrogen production on sexual development in coho salmon (Oncorhynchus kisutch) were investigated in this study through in vivo and in vitro experiments, using an aromatase inhibitor. In the in vivo studies female were injected with the aromatase inhibitor Fadrozole during vitellogenesis and close to final maturation, and males during spermatogenesis. In both females and males the effects of Fadrozole were investigated by determining the changes in plasma sex steroid levels (17β-estradiol, 17α-20p-P, testosterone and 11-ketotestosterone) before and several times after intraperitonial injection with different doses of Fadrozole, and by evaluating the reproductive development. In the in vitro studies the effects of Fadrozole, gonadotropins (GTH I and GTH II), and steroid hormone precursors (testosterone and 17α-hydroxyprogesterone) on steroid hormone secretion (17β-estradiol, 17α-20β-P, and testosterone) by coho salmon ovarian follicles were determined during vitellogenesis (immature and central germinal vesicle) and close to final maturation (peripheral germinal vesicle). The in vivo experiments in females close to final maturation showed that injection of the aromatase inhibitor Fadrozole was effective in lowering plasma 17β-estradiol levels, and an associated increase in plasma 17α-20β-P levels occurred, indicating that the shift between plasma 17β-estradiol biosynthesis and 17α-20β-P biosynthesis, which is characteristic of maturating fish, was advanced by treatment with Fadrozole. It was also shown that Fadrozole can be used as a tool to induce ovulation in coho salmon. In vitellogenic females Fadrozole reduced plasma 17β-estradiol levels in a dose and time dependent manner, and increased plasma 17α-20β levels prematurely also in a dose and time dependent manner. The switch from 17β-estradiol to 17α-20β-P biosynthesis was transient in the groups that received only one injection. The study also showed that multiple injections with Fadrozole arrested ovarian development, indicating Fadrozole may have a potential as a tool to regulate sexual development in salmon. In males, injection with Fadrozole inhibited 17β-estradiol secretion in the brain and caused a premature and transient increase in plasma 17α-20β-P levels. Multiple injections caused further increases in plasma 17α-20β-P, and 16 days after the beginning of the experiment the treatment groups which received the highest doses of Fadrozole (10 mg/kg and 5 x 10 mg/kg) started to spermiate, suggesting that the administration of aromatase inhibitors such as Fadrozole may provide a means of accelerating spermiation in salmonids and potentially other species of fish. The series of in vitro experiments demonstrated that Fadrozole is capable of inhibiting 17β-estradiol secretion throughout the periovulatory period, and that inhibition of 17β-estradiol per se does not elicit 17α-20β-P secretion, showing that gonadotropin is necessary for its secretion. It was also evident that 17p-estradiol secretion is dependent on availability of the substrate testosterone, which in turn is secreted in response to the gonadotropins. On the other hand 17α-20β-P secretion is directly dependent on stimulation of 20β-hydroxysteroid dehydrogenase by the gonadotropins, especially GTH II. These experiments demonstrated that the aromatase inhibitor Fadrozole can be used as tool to study mechanisms involved in the regulation of sexual development in fish. Also an aromatase inhibitor such as Fadrozole could be used close to final maturation to advance ovulation in females and spermiation and males and during vitellogenesis to inhibit reproductive development in females.

Fish are capable of colour vision and certain colours have been shown to affect growth and survival, skin colour, stress response, and reproduction. Beyond these physiological consequences, colour has also been shown to affect aggression levels, which is a widespread problem in aquaculture. The compatibility of fish with tank colour has been largely neglected within the aquaculture industry. Common practice is to use light blue tanks but there is no scientific basis for this choice. Closed containment aquaculture systems provide a good model to investigate the effects of tank colour on fish. Though closed containment aquaculture systems provide the opportunity for full control of environmental conditions, little research to date has investigated which parameters within these systems promote fish welfare. The aim of this study was to assess preferences of coho salmon for tank colour and determine the effects of colour on aggression. Coho salmon (n=100) were randomly assigned to 10 tanks, each bisected to allow fish to choose between two colours. Using a Latin-square design, each tank was tested with each of the following colour choices: blue vs. white, light grey, dark grey, and black, as well as black vs. white, light grey, dark grey, and a mixed dark grey/black pattern. Fish showed a strong preference for black over all other tank background options (p < 0.0001) with the exception of pattern, which was still significant but slightly less strong (p < 0.01). Moreover, darker colours in the environment resulted in lower rates of aggressive behaviours compared to lighter colours (p < 0.0001). These results present the first evidence that darker tanks are preferred by and decrease overall tank aggression levels in salmonids.
Land and Food Systems, Faculty of
Graduate

Memoria para optar al título de Ingeniero en Alimentos
Dentro de los índices de calidad, que permiten evaluar la frescura del pescado, está la determinación del contenido de aminas biogénicas. La principal intoxicación, debido a la presencia de altos niveles de aminas biogénicas, es conocida como intoxicación-histamínica, la cual es producida por altos niveles de histamina, que pueden ser generados, por la acción microbiana, cuando el pescado no es manipulado higiénicamente y es sometido a altas temperaturas. En el presente estudio se realizó una cuantificación del contenido de histamina en Salmón coho (Oncorhynchus kisutch)refrigerado (0 - 2ºC) por un período de 24 días. Se realizaron controles de histamina a los 0, 3, 6, 10, 12, 17, 19 y 24 días de almacenamiento. Se utilizaron dos técnicas analíticas: cromatografía líquida de alta resolución (HPLC) y cromatografía capilar zonal (CZE), las cuales fueron, previamente, evaluadas por el proceso de validación limitada, para dar confiabilidad a la cuantificación del analito en la muestra. Ambas técnicas analíticas presentaron resultados satisfactorios en la validación. Demostrándose, que la CZE es una reciente y ventajosa posibilidad, debido a que esta técnica mostró mejores resultados. La formación de histamina en Salmón coho almacenado refrigerado, fue nula hasta el día 12 de almacenamiento; pero aumentó progresivamente a partir del día 17. El Salmón coho, almacenado refrigerado, por 24 días, registró niveles de concentración de histamina, bajo el límite establecido por SERNAPESCA para pescados escómbridos y relacionados con escómbridos

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Consejo Nacional de Ciencia y Tecnología (CONACYT)
Os programas de melhoramento em espécies aquícolas apresentam, no geral, um número restrito de famílias e um pequeno tamanho efetivo populacional, levando ao acasalamento de animais aparentados e, consequentemente, ao aumento da endogamia. Por sua vez, maiores níveis de endogamia tendem a ocasionar queda no desempenho dos animais causada pela depressão endogâmica. O objetivo deste estudo foi estimar os níveis de endogamia e depressão endogâmica sobre as características de peso à despesca, comprimento à despesca e resistência a Piscirickettsia salmonis em uma população de salmão coho. A resistência a Piscirickettsia salmonis foi definida como o dia da morte de cada peixe após desafio conduzido em dois anos, com média de 42 dias em 2012 e 14 dias no ano de 2014. Foi utilizado um banco de dados composto por 53.504 observações, provenientes de nove gerações e 930 famílias. A estimação dos componentes de variância e endogamia foram obtidas utilizando o programa computacional AIREMLF90 e os valores de depressão endogâmica foram estimados a partir de um modelo animal. Os valores observados para o coeficiente de endogamia foram crescentes ao longo das gerações, com uma taxa média máxima de 8,75% no ano de 2014. A depressão endogâmica afetou em maior nível as características de peso à despesca e dia de morte, com redução de 6,4 e 9,2% no desempenho dos animais, respectivamente, para o nível máximo de endogamia observado (30%). Os resultados indicam a necessidade de uso de estratégias mais efetivas de controle da endogamia para a manutenção do progresso genético do programa de melhoramento de salmão coho.
Aquaculture breeding programs present, in general, low number of families and reduced effective population size, resulting in mating of related animals and, consequently, increased level of inbreeding. High inbreeding coefficient may negatively impact the animals’ performance due to inbreeding depression. The objective of this study was to estimate inbreeding coefficient and inbreeding depression on growth traits and resistance against Piscirickettsia salmonis in a coho salmon population. Resistance against P. salmonis was defined as days to death of each fish after being challenged in two different years, with an average of 42 days in 2012 and 14 days in 2014. Data of 53,504 animals from 930 families was analyzed. Variance components were estimated using the software AIREMLF90, and inbreeding depression was estimated under an animal model. An increasing rate of inbreeding was observed, attaining an average of 8.75% in 2014. Inbreeding depression was more pronounced for harvest weight (PD) and days to death (DM), in comparison with harvest length. At the highest observed inbreeding level (30%), the estimated reduction caused by inbreeding depression was equal to 6,4% for PD and 9,2% for DM. The results indicate the necessity to control inbreeding more effectively for the studied coho salmon population, to guarantee genetic progress in the long term.
CONACYT: 579741/410470

Orientador: Roberto Carvalheiro
Coorientador: Lucia Galvão de Albuquerque
Banca: Carlos Antonio Lopes de Oliveira
Banca: Humberto Tonhati
Resumo: Os programas de melhoramento em espécies aquícolas apresentam, no geral, um número restrito de famílias e um pequeno tamanho efetivo populacional, levando ao acasalamento de animais aparentados e, consequentemente, ao aumento da endogamia. Por sua vez, maiores níveis de endogamia tendem a ocasionar queda no desempenho dos animais causada pela depressão endogâmica. O objetivo deste estudo foi estimar os níveis de endogamia e depressão endogâmica sobre as características de peso à despesca, comprimento à despesca e resistência a Piscirickettsia salmonis em uma população de salmão coho. A resistência a Piscirickettsia salmonis foi definida como o dia da morte de cada peixe após desafio conduzido em dois anos, com média de 42 dias em 2012 e 14 dias no ano de 2014. Foi utilizado um banco de dados composto por 53.504 observações, provenientes de nove gerações e 930 famílias. A estimação dos componentes de variância e endogamia foram obtidas utilizando o programa computacional AIREMLF90 e os valores de depressão endogâmica foram estimados a partir de um modelo animal. Os valores observados para o coeficiente de endogamia foram crescentes ao longo das gerações, com uma taxa média máxima de 8,75% no ano de 2014. A depressão endogâmica afetou em maior nível as características de peso à despesca e dia de morte, com redução de 6,4 e 9,2% no desempenho dos animais, respectivamente, para o nível máximo de endogamia observado (30%). Os resultados indicam a necessidade de uso de estratégias ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Aquaculture breeding programs present, in general, low number of families and reduced effective population size, resulting in mating of related animals and, consequently, increased level of inbreeding. High inbreeding coefficient may negatively impact the animals' performance due to inbreeding depression. The objective of this study was to estimate inbreeding coefficient and inbreeding depression on growth traits and resistance against Piscirickettsia salmonis in a coho salmon population. Resistance against P. salmonis was defined as days to death of each fish after being challenged in two different years, with an average of 42 days in 2012 and 14 days in 2014. Data of 53,504 animals from 930 families was analyzed. Variance components were estimated using the software AIREMLF90, and inbreeding depression was estimated under an animal model. An increasing rate of inbreeding was observed, attaining an average of 8.75% in 2014. Inbreeding depression was more pronounced for harvest weight (PD) and days to death (DM), in comparison with harvest length. At the highest observed inbreeding level (30%), the estimated reduction caused by inbreeding depression was equal to 6,4% for PD and 9,2% for DM. The results indicate the necessity to control inbreeding more effectively for the studied coho salmon population, to guarantee genetic progress in the long term.
Mestre

Highly unsaturated marine lipids are common ingredients in salmon diets, and they are prone to oxidative change. The present study was undertaken to examine the growth and health of coho salmon (Oncorhynchus kisutch) fed diets containing herring oil autoxidized to different degrees. The efficacy of dietary vitamin E in ameliorating any adverse effect on performance was investigated. Herring oil was oxidized to one of two levels (relative to a control) by aeration and mild heating (40 °C). Peroxide values and iodine numbers were recorded to monitor the extent of autoxidation. Depletion of dietary linolenic acid series fatty acids (n3FA), and the labile vitamins A, C, and E, provided further evidence of the progress of lipid oxidation. The mean initial body weight was 5.1 g/fish, and growth (weight and length) was measured at 3 or 6 week intervals for 28 weeks. Experimental diets contained 16.8% lipid, primarily as herring oil. One diet was made with corn oil replacing herring oil, and another contained a combination of low and highly oxidized oil. Vitamin E (as dl-ɑ-tocopheryl acetate) was added at either 30 IU/kg dry diet or 1000 IU/kg dry diet. At 23 weeks, 1/3 of the fish were vaccinated against vibriosis. At 28 weeks the fish were twice challenged with live Vibrio sp. Immunocompetence was estimated by mortality and by plasma agglutination. The inclusion of autoxidized herring oil reduced the nutritive value of the diets. The poorer growth and feed efficiency of fish fed diets containing oxidized oils appears to have resulted from a combination of appetite suppression and nutrient deficiency. The relative importance of these factors in influencing growth and feed efficiency depended upon the extent of the oxidation, with appetite suppression being most apparent in fish fed diets containing moderately oxidized oil. Dietary supplementation with a high level of vitamin E had no ameliorating effect on growth or feed efficiency. Health and immunocompetence were not impaired by the presence of oxidized dietary lipid, or improved by the addition of vitamin E.
Land and Food Systems, Faculty of
Graduate

Rainbow trout {Oncorhynchus mykiss) and coho salmon (0. kisutch) produce males which mature at an abnormally early age. The objectives of this study were to critically describe the role of growth rate in early sexual maturation of male salmonids by monitoring growth rate and precocious sexual development in individually identified fish. Underyearling rainbow trout were individually identified using coded tags. These fish were reared at 9°C and 15°C and growth was monitored twice a month in both groups over a 9 month period starting January 24, 1989. The number of precocious males in the 9°C and 15°C groups were 11% and 18% respectively. Yearling coho salmon were similarly tagged, reared at ambient temperature, and monitored for growth over an 8 month period starting March 22nd, 1989. Ten percent of the coho salmon matured precociously. In both experiments there was a similar relationship between fast growth in early spring and precocious maturation. The growth rate of fish that matured declined in autumn relative to non-maturing individuals. Condition factor (length to weight relationship) was greater among those fish that matured precociously. Plasma growth hormone was monitored in the coho salmon. Most samples fell below the detection limits of the assay (1.5. to 3.0 ng/ml). A strategy to reduce the number of precocious males in cultured salmonids is suggested.
Land and Food Systems, Faculty of
Graduate

An experiment was designed to determine whether the response of fish to graded dietary levels of essential fatty acids (n3) was affected by the total dietary lipid concentration. Juvenile coho salmon were fed practical diets varying in lipid source and total lipid content. The diets were fed in duplicate during a 27-week and a 12-week period ran in succession. The effects of the different dietary fatty acid concentrations on body fatty acids composition were determined after each period. The dietary fatty acid classes were expressed either as percent of the dry diet or percent of the dietary lipid. Analysis of the body lipid fatty acid composition was performed for neutral and polar lipid fractions. The effect of dietary fatty acid concentration on growth and mortality was determined over a 12-week growth study (period 2). A 24-hour saltwater challenge was performed at the end of period 2. It was used to examine the effect of dietary fatty acid concentration on saltwater tolerance. Dietary n6 and n3 fatty acids appeared to be selectively incorporated into the body polar lipid pool. Linoleate and linolenate underwent elongation and desaturation which resulted in the inhibition of the elongation and desaturation of 18:ln9. The neutral lipid pool served as a source of n3 fatty acids for the polar lipid when dietary intake was limited by low temperatures during period 1. The body neutral monounsaturated and 18:1 monounsaturated fatty acids consistently reflected the composition of the diet. The n3 fatty acid concentration in the neutral lipid was also directly related to the dietary fatty acid composition during period 2. The effect of dietary fatty acids on the body neutral or polar fatty acid composition did not depend on the manner in which the dietary fatty acids were expressed. There was also no significant effect of dietary total lipid concentration on the relationship between dietary fatty acids and their incorporation into the body lipids. The growth response was difficult to interpret because of the high mortality. There was a significant difference in mortality among treatments. A positive relationship between dietary concentrations of total n3 fatty acids or n3 highly unsaturated fatty acids and mortality became evident following analysis of the regression of mortality as a function of dietary fatty acid composition. The dietary fatty acid composition did not appear to alter the saltwater tolerance of the 1+ coho salmon.
Land and Food Systems, Faculty of
Graduate

This thesis examines the ontogeny of plasma sodium regulation (an indicator of osmoregulatory ability), current or rheotactic response (an indicator of emigration timing) and salinity preference in juvenile coho salmon (Oncorhynchus kisutch). The purpose of the study was to determine if there are inherited differences in the development of these traits between coastal and interior British Columbia populations of coho. An interior (Cold water River) and a coastal (Rosewall Creek-Big Qualicum River) population were monitored for the above traits throughout the year. Both wild and laboratory groups were included in the study. The laboratory raised populations were divided into two incubation treatment groups: one incubated under a coastal temperature regime, and the other incubated under an interior temperature regime. There were no differences in the development of sodium regulatory ability between wild populations when the data were sorted by coho weight. Coastal coho, however, physiologically smolted after one year in the natal streams, while interior coho smolted after at least two years of freshwater growth. No obvious differences were noted between wild resident populations in the timing of downstream movement or the shift in salinity preference from hypotonic to isotonic and hypertonic salinities. Both of these behavioural responses typically occurred in the spring (April-May) of each year. Fyke net catches, however, sugqested that, in addition to the spring emigrations observed in both populations, a portion of the interior population migrated in the fall (November). No differences in the development of sodium regulatory ability were observed either within or between laboratory raised populations. Ion regulatory ability increased to a plateau in the fall and winter following emergence, and increased to smolting levels during the following spring (April-May). There were differences between coastal and interior populations in the pattern of development of both nocturnal current responses and the preference for isotonic or hypertonic salinities. Interior laboratory raised coho developed negative nocturnal rheotaxis and a preference for isotonic salinities about three months earlier (November) than laboratory raised coastal coho (late February-March). Within populations, no differences were observed in the ontogeny of these traits in the groups reared under different temperature regimes. Because these interpopulation ontogenetic behavioural differences persisted in fish reared under identical laboratory conditions, they probably have some genetic basis. Such an innate component in behaviour implies an adaptive role and in juvenile coho these behavioural traits may allow populations to use a variety of habitats at different distances from the sea, even though a major physiological schedule (in this case the development of ion regulatory capabilities) appears to be fixed within the species. Perhaps variations in migratory timing and salinity preference in juvenile coho evolved to assure survival in a relatively unstable and often severe environment by optimizing habitat use within the constraints of an overriding physiological schedule.
Science, Faculty of
Zoology, Department of
Graduate

This study compared chemical, physical and sensorial properties of wild and farmed fish. Farmed yellow perch fillets showed higher lipid contents (2.78% vs. 1.39%); softer texture (0.41 J/g vs. 0.53 J/g); whiter color (higher L* and lower b*values); different fatty acid profile (higher n-3/n-6 ratio), and mineral composition, when compared to their wild counterparts. Similar amino acid profiles and flavor were found between treatments. Dietary protein by itself influenced color and flavor of yellow perch fillets. Yellow perch fed the highest protein concentrations exhibited higher b* (yellow) values and overall flavor was significantly different (p â ¤ 0.05) between fish fed a 45% and 55% crude protein (CP) diet. A 12-week feeding trial determined that southern flounder protein requirement to achieve maximum weight was around 50% CP. Farmed southern flounder were found to be higher in lipid content (3.04 % vs. 1.61%), softer (0.24 J/g vs. 0/33 J/g), different in color (lower a* [green to red]), mineral, fatty acid composition (higher n-3/n-6 ratio) and flavor, than wild. The effect of a crab meal-supplemented diet, on flavor and body composition of flounder was analyzed. The inclusion of crab meal as a flavor enhancer affected the flavor and also influenced color of the fillets (lower L* [lightness] and higher b* values). Wild, farmed and growth-enhanced transgenic coho salmon (market-size) were compared, regarding their body composition and nutritional value. All treatments showed highest lipid levels in the ventral frontal sections and lowest in the tail (p â ¤ 0.05). Overall wild fish showed lower lipid levels and firmer values in the tail sections (p â ¤ 0.05). The insertion of the growth hormone gene affected lipid deposition, texture and color, since transgenic fish showed firmer texture than farmed and similar lipid contents even when fed a high-energy diet. L*, a* and b* values were similar for wild and transgenic coho in most of the body zones. Fillet mineral and amino acid profiles were similar across all groups. No differences were observed in flavor between farmed and wild coho, while panelists preferred the appearance of farmed, when compared to transgenic coho.
Ph. D.

Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations.

Heritabilties and genetic correlations using Individual Animal Model, (IAM), analysis for weight, length and survivability were determined in both freshwater and saltwater rearing of s0 and si1 coho, (Oncorhynchus kisutch). The most important trait to salmon farmers is the saltwater market weight which was found to have heritability estimates of 0.21 and 0.45 for the s1 and s0 smolts. Estimates of heritability for survival were high, (0.29 and 0.21) for both s0 and s1 rearing strategies. Genetic correlations between freshwater and saltwater size were small, (0.33 to 0.59) indicating selection for market weight should be done during the saltwater market weight window. Significant differences were found for weight and length between strains during freshwater and saltwater rearing for both s0 and si1 coho. The northern strains, (Kitimat, Bella Coola and Pallant Creek) were significantly larger in weight and length thanthe southern strains, (Big Qualicum and Robertson Creek). The Kitimat strain was larger in weight and length than the Bella Coola and Pallant Creek strains but lower than these two strains for percent survivability. When comparing fish from the Kitimat strain reared on both a s0 and s1 rearing strategy, it was found that the s1 fish were significantly larger than the s0 fish at the market weight window.
Land and Food Systems, Faculty of
Graduate

Memoria para optar al Título Profesional de Médico Veterinario
La piscirickettsiosis es una enfermedad bacteriana producida por Piscirickettsia salmonis (P. salmonis) que provoca severas pérdidas económicas a la industria del salmón en el sur de Chile por conceptos de mortalidad, tratamientos antimicrobianos y el uso de vacunas. Debido a que su signología no es patognomónica se debe recurrir a pruebas de laboratorio para determinar la presencia de su agente etiológico con el fin de establecer medidas de control y tratamientos adecuados. A pesar de que la enfermedad fue descrita en 1989, la patogénesis y las vías de transmisión de la bacteria se encuentran insuficientemente descritas, por lo que la presente Memoria de Título tuvo como uno de sus objetivos determinar la presencia y asociación de P. salmonis en distintas muestras de 19 peces de la especie salmón coho (Oncorhynchus kisutch) afectados por piscirickettsiosis. En esta Memoria de Título se determinó la presencia de P. salmonis mediante la técnica de Reacción en Cadena de la Polimerasa anidada (PCR anidado) en el 79%, 95% y 87% de las muestras de hígado, riñón y heces respectivamente. El análisis estadístico realizado mediante el coeficiente de Kappa, determinó que hígado-riñón y riñón-heces están considerablemente asociados, mientras que hígado-heces poseen una moderada asociación. Adicionalmente, de cada órgano estudiado se realizó un análisis por separado de tres fragmentos de tejido con el fin de establecer si existía consistencia en el diagnóstico entre ellas. Los resultados (analizados también con el coeficiente de Kappa), indicaron débil asociación entre las muestras analizadas, lo que sugiere un riesgo para la detección del agente según el fragmento que se utiliza. Al aumentar la cantidad de tejido analizado se demostró que aumenta la posibilidad de detección de la bacteria. Por otra parte, este estudio constituye el primer reporte de la presencia de la bacteria en heces de salmón coho en condiciones de cultivo en mar a través de la técnica de PCR anidado. No obstante lo anterior, son necesarios más estudios para establecer la viabilidad de la bacteria en el contenido fecal.
Piscirickettsiosis is a bacterial disease caused by Piscirickettsia salmonis. It causes severe economic losses in the salmon industry in southern Chile by concepts of mortality, antimicrobial treatments and the use of vaccines. The clinical signs are not pathognomonic and because of that laboratory tests are required to determine the presence of its causative agent in order to establish control measures and treatments. Piscirickettsiosis was described in 1989 but up to this day, the pathogenesis and transmission routes of the bacteria are still inadequately described, because of that reason one of the main objectives of this work was to determine the presence and association of P. salmonis in different samples of 19 coho salmon (O. kitsuch) affected by piscirickettsiosis. The presence of P. salmonis was determined by the technique of Nested Polymerase Chain Reaction (nested PCR) in 79%, 95% and 87% of the samples of liver, kidney and feces respectively. The statistical analysis performed using the Cohen's Kappa coefficient, found that liver-kidney and kidney-feces are significantly associated, whereas liver-feces have a moderate association. Additionally, separate analysis was made of three pieces of tissue in order to establish whereas the diagnosis between them was consistent. The results (also analyzed with Cohen's Kappa coefficient) indicated weak association between the samples analyzed, suggesting a detection risk according to the fragment analyzed. It was demonstrated that increasing the amount of analyzed tissue increases the detectability of the bacteria. Moreover, this study is the first report about the presence of P. salmonis in coho salmon feces in sea farming conditions through technical of nested PCR. Further studies are necessary to establish the viability of the bacteria in the fecal content.
Financiamiento: Laboratorio Nacional de Referencia para el Diagnóstico de Enfermedades de Especies Hidrobiológicas, U. de Chile. Salmones Humboldt Ltda.

Memoria para optar al título de Ingeniero en Alimentos
La industria chilena del Salmón ha alcanzado en el plano nacional e internacional gran importancia, transformándose en el segundo productor mundial de este producto. Entre las variedades producidas se encuentra el Salmón coho_(Oncorhynchus Kisutch), del cual se tienen escasos antecedentes en lo referente a su comportamiento en el almacenamiento congelado, lo anterior es el motivo de la realización de este estudio. El objetivo del presente trabajo fue estudiar la estabilidad del color, propiedades químicas y físicas del músculo de Salmón coho entero HG (sin cabeza ni vísceras) durante el almacenamiento congelado a -20ºC durante un año, dentro del cual se efectuaron 6 controles, con 5 individuos extraídos al azar para cada punto de control. Se realizó un análisis centesimal, el cual no varió respecto a datos bibliográficos encontrados para Salmón coho. Se determinó frescura en el Salmón coho utilizando parámetros tales como: dimetilamina, formaldehído y nitrógeno básico volátil total, de los cuales sólo el último se vio aumentado en el tiempo, aunque sin sobrepasar el límite establecido por la ley que corresponde a 30mg/100g músculo. El estudio también contempló la determinación de pH, el cual no tuvo una variación significativa en el tiempo (p>0,05), observándose un pH de 6,06 y 6,27 al inicio y final del estudio, respectivamente. Se realizaron diversos análisis texturales dentro de los cuales se encuentra; dureza, cizalla o firmeza y gaping. Analizando los resultados obtenidos se observó una disminución brusca de la dureza a partir del cuarto mes y la firmeza aumentó hasta el mes 6, disminuyendo posteriormente. El gaping evaluado aumentó paulatinamente sin llegar a un deterioro extremo, alcanzando hasta el mes 8 calidad premium con grado 3. Las propiedades de retención de agua también fueron medidas; el driping cocido presentó la mayor perdida de líquido en el mes 0 (16,51%), luego disminuyó hasta el mes 8, aumentando en los siguientes meses de estudio. El driping crudo aumentó hasta el mes 6 (3,46 % de exudado), y luego disminuyó presentando en el mes 12 un 1,52 %. También se evaluó capacidad de retención de agua relativa y la humedad exprimible, observándose en ambas un disminución, de un 56,1% en el caso de retención de agua y de 52,7% en la humedad exprimible. Tres análisis de color fueron realizados: color visual, instrumental y mediciones de astaxantina. Según el primero el Salmón puede clasificarse como categoría premium hasta el mes 8. Las mediciones instrumentales no mostraron una tendencia clara en el cambio de color. La cantidad de astaxantina encontrada en los salmones varió significativamente en el tiempo, sin embargo, los valores iniciales y finales fueron similares. De acuerdo al conjunto de análisis hasta el mes 8 el salmón se puede clasificar como Premium, siendo la textura y color los parámetros limitantes

An investigation was initiated in southern British Columbia during 1984 to determine the degree of similarity between populations of coho salmon, in terms of their demographic traits and exploitation patterns. Fourteen stocks of wild or hatchery origin were subject to coded-wire tagging in nine different streams located within a 150 km region of southeast Vancouver Island during 1985,1986, and 1987. Escapement enumeration and tag recovery were conducted during the 1985-1988 period in all streams by means of counting fences and stream surveys. A new mark-recapture model was formulated specifically for estimating escapement levels in natural streams where only a partial enumeration of spawners is possible. Estimates of the number of tags recovered in various sport and commercial fisheries were generated primarily on the basis of catch and sampling records extracted from the Mark-Recovery Program database, located at the Pacific Biological Station of the Canadian Department of Fisheries and Oceans. Estimates of sampling rates in the Strait of Georgia sport fishery were determined from simulation studies based on catch and sampling statistics associated with the Georgia Strait Creel Survey and Head Recovery programs. Populations were contrasted in terms of their juvenile migration patterns, smolt-to-adult survival, catch distributions, straying rates, escapement patterns, run composition, adult sizes, and exploitation rates. Considerable variation in smolt size and juvenile migration time was detected among populations each year. The most pronounced difference was the consistently shorter migration period of smolts released from public hatcheries. Estimates of ocean survival was highly variable across years and streams, and even among stocks within the same stream. No particular stock or stock type had consistently higher survival, but hatchery fish from the Big Qualicum River exhibited consistently lower survival. Considerable variation was observed in the duration and timing of various runs within the study area. On average, the contribution of strays to each spawning population was relatively small (< 2%), but strays could account for as much as 50% of the escapement to a given stream. Average exploitation rates were in the neighborhood of 80% each year, but were as high as 96% for some stocks. Substantial differences in exploitation rate were detected between stocks from the same stream, and between stocks from adjacent streams, but exploitation rates were not consistently higher or lower for any particular stock or stock type. The influence of specific factors upon straying rates, survival rates and exploitation patterns was estimated by means of log-linear models. Stock contributions to various fisheries appeared to be related to the release location, and two stock assemblages were identified within the study area based on the level of similarity among stocks in fishery contribution. Attempts to quantify the level of co-variation among stocks in survival and exploitation rates were hampered by the lack of sufficiently long time series of data, but preliminary results gave no indication of a high level of similarity among stocks or stock types. Still, it was possible to identify stocks which could be used as indicators of the general status of all stocks in the study area in terms of escapement trends, smolt-to-adult survival and exploitation rates. Based on the level of similarity observed, indicator stocks are considered to be useful stock-assessment tools, and can provide useful information for management purposes.
Science, Faculty of
Zoology, Department of
Graduate

Memoria para optar al título de Ingeniero en Alimentos
En la actualidad, Chile se ubica en el segundo lugar de los rankings de producción de salmónidos a nivel mundial, lo que convierte al salmón en el producto alimenticio más importante de nuestras exportaciones pesqueras y en el principal motor económico de las regiones X y XI del país. El empleo de antioxidantes en las dietas para salmónidos es fundamental para retardar su deterioro. Los antioxidantes que se emplean actualmente son, en su mayoría, compuestos de origen sintético cuya inocuidad está siendo cada vez más cuestionada a nivel internacional. Este estudio trata acerca de la adición de antioxidantes naturales inocuos (tocoferoles y extracto de romero (Rosmarinus officinalis)) en la dieta de Salmón coho (Oncorhynchus kisutch) de exportación, adicionándolos tanto en la harina de pescado como en el aceite de pescado y poder medir su efecto en la calidad del producto congelado durante 18 meses. Se consideró el empleo de 3 jaulas con salmones en cultivo de la Región X de Chile: los individuos de la primera jaula se alimentaron con la dieta control que contenía etoxiquina (harina de pescado) y BHT (aceite de pescado) (Dieta I); los de la segunda se alimentaron con una dieta experimental que contenía un exceso de tocoferoles libres ( tanto en la harina como en el aceite de pescado) (Dieta II); y los de la tercera con otra dieta experimental que contenía una mezcla antioxidante de tocoferoles libres (harina de pescado) con extracto de Romero (Aceite de pescado) (Dieta III), durante un tiempo aproximado de 85 días. Cumplido ese tiempo, los salmones se sacrificaron y procesaron industrialmente, para obtener salmón congelado de exportación tipo HG y fueron enviados a Santiago para ser almacenados a -18ºC y oportunamente analizados. Se analizaron 5 individuos de una población de 1200 individuos para la jaula 1 y de 500 individuos para la jaula 2 y 3, cada uno en duplicado con una frecuencia de 3 meses durante 18 meses. Los parámetros analizados periódicamente para cada dieta fueron: grupos sulfhidrilos, grupos sulfuros, grupos carbonilos además de la cuantificación proteica de cada parámetro. Debido a que todos estos parámetro de calidad y oxidación analizados al utilizar las 3 dietas en estudio fueron estadísticamente equivalentes y que ninguno de ellos fue afectado significativamente en forma negativa con las mismas, se concluye que el reemplazo de antioxidantes sintéticos por naturales en la dieta de Salmón coho (Oncorhynchus kisutch), es una alternativa factible a nivel técnico y recomendable si se desea ampliar el ingreso del salmón chileno a mercados cuyas tendencias estén a favor de una alimentación más natural y sana

Memoria para optar al Título Profesional de Médico Veterinario
El presente trabajo tuvo como objetivo evaluar la respuesta productiva, indicadores de calidad de canal y el costo de alimentación de salmones Coho, al emplear dietas con distintas razones de proteínas/lípidos (P/L). Para ello se utilizaron 3300 salmones Coho nacionales, con un peso promedio inicial de 1121 g. Los peces fueron asignados al azar a tres tratamientos con dos repeticiones, de 550 peces cada una. Los peces del primer tratamiento (control) se alimentaron con una dieta que contenía 45% de proteínas y 22% de lípidos (2,04 P/L), los del segundo tratamiento con 43% de proteína y 26% de lípidos (1,65 P/L), y los del tercer tratamiento, 40% de proteína y 30% de lípidos (1,33 P/L). La respuesta productiva se evaluó por medio del consumo de alimento, ganancia de peso, eficiencia de conversión alimenticia, tasa de crecimiento específico y peso final. La calidad de canal se evaluó por medio de la longitud corporal, factor de condición, peso eviscerado, rendimiento de la canal, peso de las vísceras, peso del hígado, peso gonadal, contenido de grasa perivisceral y espesor de la pared abdominal. Las respuestas productivas fueron similares en los tres tratamientos, salvo en el peso final de los salmones, que fue mayor en los tratamientos con razones P/L más estrechas (p 0,05), al igual que los machos respecto de las hembras (p 0,02). Con relación a las características de calidad de canal, la dieta del segundo tratamiento tuvo en general un mejor comportamiento en la mayoría de las variables registradas, al igual que los machos respecto de las hembras, sin embargo, las respuestas fueron diversas. El factor de condición y el rendimiento de la canal no fueron modificados por los distintos tratamientos y el depósito de grasa perivisceral fue mayor en dietas con razones de P/L más estrechas. El empleo de dietas con razones de P/L más estrechas, tuvo como consecuencia un aumento en el costo de alimento por kilo de salmón ganado de un 8,77% para la dieta 2 y de un 1,59% para la dieta 3, tomando como base la eficiencia de conversión alimenticia alcanzada en cada tratamiento.
FONDEF N° D 98-1-1069

Memoria para optar al título de Ingeniero en Alimentos
En la actualidad, Chile se ubica en el segundo lugar de los rankings de producción de salmónidos a nivel mundial, lo que convierte al salmón en el producto alimenticio más importante de nuestras exportaciones pesqueras y en el principal motor económico de las regiones X y XI del país. Por ello, cada vez se hace más importante contar con nueva información basada en investigación, que sea capaz de responder y adelantarse a potenciales problemas, que posibilite el mejoramiento de la calidad de los salmónidos y de los productos derivados de ellos. El empleo de antioxidantes en las dietas para salmónidos es fundamental para retardar su deterioro, puesto que las materias primas principales que se emplean para elaborarlas son harina y aceite de pescado, insumos muy susceptibles a sufrir los ataques de la peroxidación lipídica. Los antioxidantes que se emplean actualmente para elaborarlas son, en su mayoría, compuestos de origen sintético cuya inocuidad está siendo cada vez más cuestionada a nivel internacional. Este estudio trata acerca del reemplazo de antioxidantes sintéticos por dos productos antioxidantes naturales inocuos (tocoferoles y extracto de romero (Rosmarinus officinalis)) en la dieta de Salmón coho (Oncorhynchus kisutch) de exportación y su efecto en la calidad del producto congelado durante 12 mese. Se consideró el empleo de 3 jaulas con salmones en cultivo de la Región X de Chile: los individuos de la primera jaula se alimentaron con la dieta control que contenía etoxiquina y BHT (Dieta I); los de la segunda se alimentaron con una dieta experimental que contenía un exceso de tocoferoles libre (Dieta II); y los de la tercera con otra dieta experimental que contenía una mezcla antioxidante de tocoferoles libres con extracto de romero (Dieta III), durante un tiempo de 80 días. Cumplido este tiempo, los salmones se sacrificaron y procesaron industrialmente, para obtener salmón congelado de exportación tipo HG y fueron enviados a Santiago para ser almacenados a -18º C y oportunamente analizados. Se analizaron cinco individuos con una frecuencia de 3 meses durante un año, a excepción de la composición proximal, que se efectuó en duplicado y solamente al inicio y al final del estudio. Los parámetros analizados periódicamente fueron: contenido de humedad, porcentaje de materia grasa, cuantificación de ácidos grasos poliinsaturados [omega]3, determinación del índice de polienos, índice de peróxidos, valor de p-ansidina, valor-pH, nitrógeno básico volátil total (NBVT), dimetilamina, formaldehído y cuantificación de tocoferoles libres. En las tres dietas empleadas en el estudio se determinó la composición proximal, el contenido de tocoferoles libres y la estabilidad oxidativa. Debido a que la gran mayoría de los parámetros de calidad analizados al utilizar las 3 dietas en estudio fueron estadísticamente equivalentes, y algunos incluso mejores con el empleo de las dietas experimentales; y a que ninguno de ellos fue afectado significativamente en forma negativa con las mismas, se concluye que el reemplazo de antioxidantes sintéticos por naturales en la dieta del Salmón coho (Oncorhynchus kisutch), es una alternativa factible a nivel técnico y recomendable si se desea ampliar el ingreso del salmón chileno a mercados cuyas tendencias estén a favor de una alimentación más natural y sana

Memoria para optar al título de Ingeniero en Alimentos
El hielo líquido es un novedoso método de conservación de productos marinos que presenta una serie de ventajas en comparación al tratamiento con hielo en escamas, entre las cuales se destacan un rápido enfriamiento, menores .temperaturas y menor daño superficial al pescado. Este estudio tiene como objetivo comparar el efecto de esta técnica frente a la del hielo en escamas en salmon Coho (Oncorhynchus kisutch) cocido y en conserva sobre sus propiedades físicas, químicas y sensoriales. Se analizaron muestras cocidas y enlatadas conservadas en ambos tipos de hielo durante 0, 5 y 9 días. En las muestras enlatadas se analizó el músculo y el líquido de cobertura. Se realizaron análisis físicos: test de cizalla y color instrumental; análisis químicos: pH e índice de anisidina y evaluación sensorial por medio del test descriptivo cuantitativo. Para el salmón cocido, los resultados mostraron que el hielo líquido fue mejor evaluado en el test de cizalla y pH. En el filete de salmón en conserva obtuvo mejores resultados en firmeza (test de cizalla) y luminosidad (L*) medida en forma instrumental y sensorial. Por último en el aceite de cobertura, la evaluación sensorial indicó que presentaba una menor turbidez, menor cantidad de partículas en suspensión y mayor luminosidad

Memoria para optar al título de Ingeniero en Alimentos
La acuicultura, actividad que tiene por objeto la producción de recursos hidrobiológicos organizada por el hombre, busca en hacer crecer el pez lo más rápido posible empleando la menor cantidad de alimento, dado que el este constituye el mayor componente del costo en acuicultura y es el factor de mayor impacto en la composición química del músculo de salmón. Este estudio trata de la adición de dos antioxidantes naturales, tocoferoles y extracto de romero, a la dieta de engorda del Salmón coho (Oncorhynchus kisutch), reemplazando los antioxidantes presentes en la materia prima, en la harina de pescado se reemplazó etoxiquina de tocoferol y en el aceite de pescado el BHT por un extracto de tocoferoles libres y por extracto de romero; y su efecto en parte de la fracción proteica del producto congelado a -18°C por un período de 18 meses. Se alimentaron los salmones con tres dietas: Dieta I o Control, la cual contenía BHT y etoxiquina, Dieta II, con un exceso de tocoferoles y Dieta III, adicionada con extracto de romero. Se analizaron los parámetros de actividad proteolítica, glutatión peróxidasa y metaloproteinasas para 5 individuos cada 3 meses durante el período de almacenamiento. La Actividad Proteolítica en músculo de Salmón coho, no presentó diferencias (p > 0,05), durante los seis primeros meses de almacenamiento al comparar las tres dietas de engorda en estudio, lo que indica que la adición de antioxidantes naturales no afecta este parámetro hasta el sexto mes de almacenamiento. Cabe destacar sí, la alta desviación estándar que presentaron todos los individuos analizados y la buena correlación de este parámetro con “driping cocido” en el caso de los salmones alimentados con la Dieta I o Control y con RAM para los individuos alimentados con la Dieta III (Extracto de Romero). La actividad de la enzima glutatión peróxidasa para las muestras de músculo de Salmón coho provenientes de las tres dietas de engorda en estudio, no presentódiferencias en su comportamiento (p > 0,05) a partir del noveno mes de almacenamiento, lo cual indicaría que a partir de este mes los antioxidantes naturales adicionados no favorecen ni retardan la actividad de ésta enzima. En este caso se encontró buena correlación con índice de peróxidos en el caso de los salmones alimentados con la Dieta I o Control. Con respecto a las metaloproteinasas, las muestras se Salmón coho, provenientes de individuos alimentados con las tres diferentes dietas de engorda, presentaron actividad gelatinásica cercanas a 85 y 18kD. Esta actividad no presentó diferencias en su comportamiento (p > 0,05) con respecto a los individuos analizados durante todo el período de almacenamiento. En este caso se encontró buenas correlación de la actividad gelatinásica cercana a 18kD con “gaping” en el caso de los salmones alimentados con la Dieta I o Control y “driping crudo” para los individuos alimentados con la antes mencionada y la Dieta III (Extracto de Romero). Para la actividad gelatinásica a cercana 85 kD con “driping crudo” en el caso de los salmones alimentados con la Dieta I o Control y con “unidades formadoras de colonias” para los individuos alimentados con la Dieta III (Extracto de Romero)

Tesis para optar al grado de Magíster en Ciencia de los Alimentos
Se realizó un estudio comparativo del efecto del reemplazo de antioxidantes sintéticos (etoxiquina y BHT) por dos antioxidantes naturales (tocoferoles y extracto de romero (Rosmarinicus officinalis) en la dieta del salmón Coho (Oncorhynchus kisutch) de exportación durante la etapa de engorde sobre la calidad bioquímica, física, microbiológica y sensorial del producto durante 18 meses de almacenamiento congelado a (-18 °C). Se consideró el empleo de 3 jaulas con salmones cultivados por EWOS Innovation Research de la X región de Chile. Los salmones con un peso aproximado de 1500 g fueron alimentados durante 80 días con tres diferentes tipos de dietas: Dieta I: condiciones tradicionales con BHT y etoxiquina correspondió al control, Dieta II: enriquecida con α–tocoferol, y Dieta III enriquecida con α–tocoferol más extracto de romero (Rosmarinicus officinalis) hasta que alcanzaron la etapa de engorde con un peso de 2500 g. Luego fueron cosechados por Mainstream (Calbuco, Chile) y procesados obteniéndose salmón congelado de exportación tipo HG. Posteriormente a este proceso, se transportaron al Laboratorio de Procesos de Ingeniería en Alimentos de la Facultad de Ciencias Químicas y Farmacéuticas de la Universidad de Chile donde fueron congelados a (-18 °C) durante 18 meses. Se efectuaron 6 controles en el tiempo (meses 0, 3, 6, 9, 12 y 18), con 5 individuos extraídos al azar en cada punto de control. La evolución de los cambios bioquímicos fue medida mediante solubilidad de proteínas y actividad ATPásica Ca+2. Los métodos realizados para medir los cambios en las propiedades funcionales fueron humedad exprimible, capacidad de retención de agua, dripping o exudado en músculo crudo y cocido. A nivel de propiedades texturales se estudiaron ensayo de compresión y prueba de cizalla en músculo crudo y cocido, gaping o desgajamiento y microestructura por microscopía electrónica de transmisión. Se realizó análisis descriptivo cuantitativo para medir la evolución de las propiedades sensoriales y a nivel microbiológico se analizó recuento de microorganismos aerobios mesófilos (RAM), recuento de enterobacterias, recuento de microorganismos patógenos (Salmonella sp., Staphylococcus aureus, y coliformes totales y fecales). Los análisis estadísticos arrojaron ausencia de diferencias significativas entre individuos y réplicas. Mientras que, el tiempo de almacenamiento y las dietas afectaron significativamente los parámetros bioquímicos, físicos, microbiológicos y sensoriales. La textura y propiedades funcionales del salmón disminuyeron en el tiempo. Los cambios experimentados en estos parámetros son producidos por la desnaturalización y agregación de las proteínas presentes en el músculo del salmón, que es debida al almacenamiento congelado. Lo anterior se puede apreciar claramente por los estudios bioquímicos donde la solubilidad y actividad ATPasa disminuyeron paulatinamente en el tiempo. Al mes 9, la solubilidad de la Dieta I decreció en un 72,4% mientras que, la Dieta II y III disminuyeron en un 17,8% y 44,7% respectivamente, en tanto que la actividad ATPásica para las dietas I, II y III disminuyó al mes 12, un 40,5%, 65,3% y un 69,2% respectivamente. También se observaron cambios en la microestructura del músculo de salmón principalmente en la dieta control se produjeron los mayores daños que afectaron directamente a la estructura de los sarcómeros. En el mes 9, se observó una discontinuidad de la línea-Z (bandas oscuras) hasta prácticamente desaparecer en el mes 18. El análisis multivariado indicó que la firmeza del músculo cocido, gaping y % de agua perdida explican la evolución de las propiedades funcionales del músculo de salmón Coho almacenado a (-18º C) durante 18 meses (p≤0,05). Al respecto, el gaping aumentó paulatinamente sin llegar a un deterioro extremo, manteniendo hasta el mes 15 calidad Premium con grado 3 para las dietas II y III, mientras que la dieta control presentó dicha calidad hasta el mes 9. Las tres dietas (I, II y III) incrementaron la pérdida de agua hasta el duodécimo mes, que se tradujo en una disminución en la CRA en un 14%, 30% y 50% respectivamente. Como resultado de las tres dietas, se observó una disminución de la dureza y la cohesividad del músculo crudo a partir del mes 12 mientras que, la firmeza del músculo cocido aumentó hasta el mes 9 para luego disminuir hasta el último mes de almacenamiento. Las dietas tuvieron una influencia significativa en la percepción de olores y sabores, comportándose de mejor forma las dietas con antioxidantes naturales que las que contenían antioxidantes sintéticos. La dieta I (control) se caracterizó por presentar el mayor desarrollo a sabor rancio cocido y menor sabor típico cocido, a diferencia de la dieta II (α-tocoferol) que no presentó un desarrollo significativo de olores y sabores a rancio por parte de los panelistas. La calidad microbiológica presentó valores inferiores a los límites de calidad de ser rechazable. Se concluye que el reemplazo de antioxidantes sintéticos por naturales, α-Tocoferol o extracto de romero, en la dieta el salmón coho (Oncorhynchus kisutch), mantiene las calidades evaluadas en este estudio y la vida útil del salmón. Por lo cual, es una alternativa factible a nivel técnico y recomendable si se desea ampliar el ingresos del salmón chilenos a mercados cuyas tendencias estén a favor de una alimentación más natural y sana
A comparative study of the effect of the replacement of synthetic antioxidant (etoxiquina and BHT) by two natural antioxidant (tocoferoles and extract of rosemary (Rosmarinicus officinalis)) in the diet of Coho salmon (Oncorhynchus kisutch) of export during the phase of fattening on the biochemical, physical, microbiological and sensory quality of the product during 18 months of storage frozen to (-18 °C). The use was considered of 3 cages with salmons cultivated by EWOS Innovation Research of the X region of Chile. The salmons with an approximated weight of 1500 g were fed during 80 days with three different types of diets: Diet I: traditional conditions with BHT and etoxiquina corresponded to the control, Diet II: enriched with α-tocoferol, and Diet III enriched with α-tocoferol more extract of rosemary (Rosmarinicus officinalis) until they reached the stage of fattening with a weight of 2500g. Soon they were harvested and process by Mainstream (Calbuco, Chile), obtaining frozen salmon of export type HG. Later to this process, they were transported to the Laboratory of Processes of Food Engineering of the Faculty of Chemical and Pharmaceutical Sciences of the University of Chile where they were frozen to (-18 °C) during 18 months. 6 controls in the time took place (months 0, 3, 6, 9, 12 and 18), with 5 individuals extracted at random in each control point. The evolution of the biochemical changes was measured by means of solubility of proteins and activity ATPásica Ca+2. The made methods to measure the changes in the functional properties were expressible moisture, water-holding capacity, dripping or exuded in crude and cook muscle. At level of texture properties they studied test of compression and test of shears in crude and cook muscle, gaping and microstructure by electronic microscopy of transmission. Quantitative Descriptive Analysis was made to measure the evolution of the sensory properties and at microbiological level was analyzed count of aerobic mesophiles was analyzed (RAM), count of family enterobacteriaceae, count of pathogenic microorganisms (Salmonella sp., Staphylococcus aureus and total and fecal coliforms). The statistical analyses threw absence of significant differences between individuals and retorts. Whereas, the time of storage and the diets affected the significantly parameters, biochemical, physical, sensory and microbiological The texture and functional properties of the salmon diminished in the time. The changes experienced in these parameters are produced by the denaturation and aggregation of present proteins in the muscle of the salmon that must to the frozen storage. The previous thing can be appreciated clearly by the biochemical studies where the solubility and ATPasa activity diminished gradually in the time. To month 9, the solubility of Diet I decreased in a 72,4% whereas, Diet II and III diminished in a 17,8% and 44,7% respectively, whereas the ATPásica activity for diets I, II and III diminished to month 12, a 40.5%, 65.3% and a 69.2% respectively. Also changes in the microstructure of the muscle of salmon were observed; mainly in the diet control took place the greater damages than they directly affected the structure of the sarcomeres. In month 9, a discontinuity of the line-Z was observed (dark bands) until practically disappearing in month 18. The multivariate analysis indicated that the firmness of the cooked muscle, gaping and lost percentage of water explain the evolution of the functional properties of the muscle of Coho salmon stored to -18º C during 18 months (p≤0,05). On the matter, gaping increase gradually without arriving at an extreme deterioration, maintaining until month 15 Premium quality with grade 3 for diets II and III, whereas the diet control presented this quality until month 9. The three diets (I, II and III) increased the loss of water until the twelfth month, that was translated in a diminution in the CRA in 14%, 30% y 50% respectively. Like result of the three diets, a diminution of the hardness and the cohesively of the crude muscle as of month 12 was observed whereas, the firmness of the cooked muscle increased until month 9. soon to fall until the last month of storage. The diets had a significant influence in the perception of scents and flavors, behaving of better form the diets with natural antioxidants that those that contained synthetic antioxidants. Diet I (control) was characterized to present the greater development to rancid flavor cooked and smaller cooked typical flavor, unlike the diet II (α-tocoferol) that did not present a significant development of scents and flavors to rancid on the part of the judges. The microbiological quality presented inferior values to the limits of quality of being rejectable. One concludes that the replacement of synthetic antioxidants by natural, α-tocoferol or extract of rosemary, in the diet the salmon Coho (Oncorhynchus kisutch), maintains the qualities evaluated in this study and the life utility of the salmon. Thus, it is a feasible alternative at technical and recommendable level if it is desired to extend the Chilean income of the salmon to markets whose tendencies are in favor of one more a more natural feeding and heals

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Os objetivos deste trabalho foram: (i) testar a eficiência do algoritmo de seleção de acasalamento (MS) em controlar o nível de endogamia e coascendência, além de aumentar os ganhos genéticos; (ii) incluir a variabilidade genética da futura progênie como componente de otimização na função objetiva de seleção de acasalamento usando dados de dois programas de melhoramento aquícolas; e (iii) comparar a MS com a seleção truncada (TS) e contribuição genética ótima (OCS), combinados com diferentes estratégias de acasalamentos para controlar a endogamia e manter os mesmo níveis de ganhos genéticos. Para os objetivos (i) e (ii), o total de 8.782 tilápias do Nilo (NT) de cinco gerações e 79.144 salmões coho (CS) de oito gerações foram utilizados para otimizar as funções objetivos e vinte gerações discretas foram simuladas para o objetivo (iii), considerando 50 famílias e 2.000 filhos por geração, e uma característica com herdabilidade igual a 0.30. As OFs foram otimizadas considerando a coascendência média dos pais, o mérito genético esperado, a endogamia da futura progênie para os objetivos (i) e (iii) e a variabilidade genética da futura progênie foi adicionada na OF para o objetivo (ii). Para o objetivo (i), a MS permitiu reduzir a endogamia em até 73% para tilápia do Nilo, em comparação com a seleção truncada e até 20% para o salmão coho, em comparação com o cenário real de acasalamento. No objetivo dois, a MS permitiu produzir progênie com maior (DP = 0.77 e 0.30 para NT e CS, respectivamente) ou menor (DP = 0.25 e 0.14 para NT e CS, respectivamente) dispersão dos valores genéticos, dependendo da função objetivo otimizada. A seleção de acasalamentos superou a seleção truncada e o cenário real de acasalamento e também foi possível alterar a variabilidade genética da futura progênie, quando esse componente foi considerado na OF utilizado os dados reais. Para os dados simulados, a MS teve melhor performance comparada com a TS e a OCS combinada com acasalamentos aleatórios. A curto-prazo, a MS foi mais eficiente do que a OCS combinada com os acasalamentos que minimizam a endogamia em controlar a endogamia sob o mesmo nível de ganho genético. Porém, a longo prazo os resultados entre as duas estratégias foram muito semelhantes. De forma geral, o algoritmo de seleção de acasalamentos foi eficiente e flexível em otimizar a função objetiva usando diferentes componentes, em diferentes aplicações práticas na aquicultura.
The aims of this work were: (i) test the efficiency of mate selection (MS) algorithm in controlling the inbreeding and coancestry level, as well, increase the genetic gain; (ii) include the genetic variability of the future progeny as component for the optimization of the MS objective function in two aquaculture real dataset; and (iii) compare MS among truncation selection (TS) and optimum contribution selection (OCS) scenarios combined to different mating strategies to assess the best method in controlling inbreeding and maintain the genetic gain, for aquaculture breeding using simulated dataset. For objective (i) and (ii), a total of 8,782 Nile tilapias (NT) from five generations and 79,144 coho salmon (CS) from eight generations were used to optimize the objective functions (OF) and twenty discrete generations were simulated for the objective (iii), considering 50 families and 2,000 offspring per generation, and a trait with heritability of 0.30. The OFs were optimized accounting to coancestry of parents, expected genetic merit and inbreeding of the future progeny for the objective (i) and (iii) and in addition the genetic variability of the future progeny was considered for the objective (ii). For the objective (i), the mate selection allowed reducing inbreeding up to 73% for NT, compared with truncation selection, and up to 20% for CS, compared with realized scenario. In the objective (ii), MS allowed producing animals with higher (SD = 0.77 and 0.30 for NT and CS, respectively) or lower (SD = 0.25 and 0.14 for NT and CS, respectively) dispersion of estimated breeding value, depending on the objective function optimized. For real data set the MS outperformed the real mates and truncation selection and in addition the genetic variability of the future progeny could be changed when this component was considered in the OF. For the simulated dataset, the MS outperformed the TS and OCS followed by random mating. In the short-term, MS was more efficient than OCS + inbreeding minimizing in controlling inbreeding under the same genetic gain. However, in the long-term, OCS and MS resulted in similar genetic progress and average inbreeding, under the same weight on coancestry. In general, the mate selection algorithm was efficient and flexible to optimize objective functions accounting for different components, under practical applications in aquaculture breeding.
14/20626-4 e 15/25232-7

Memoria para optar al título de Ingeniero en Alimentos
La acuicultura en Chile en los últimos diez años ha registrado un radical proceso de expansión, constituyéndose en el sector de crecimiento más rápido dentro de la producción alimentaria mundial. En la actualidad la seguridad de los antioxidantes sintéticos está cuestionada y su uso en la industria alimentaria está severamente restringido por la ley, tanto en su aplicación como el nivel de uso, debido a la posible actividad como promotores cancerígenos y la actual tendencia a reemplazar los aditivos sintéticos por naturales, lo cual ha estimulado a evaluar la efectividad de estos compuestos naturales que poseen propiedades antioxidantes. Este estudio trata la variación de la calidad sensorial y propiedades funcionales del músculo del salmón coho (Oncorhynchus kisutch) cuando es alimentado con dietas adicionadas de antioxidantes naturales, tales como extracto de romero y/o α-tocoferol y conservado al estado congelado durante 18 meses. Para este estudio se empleó el uso de tres dietas, la dieta I que contenía etoxiquina y BHT (dieta control), la dieta II que contenía un exceso de tocoferoles libres y la dieta III que contenía α-tocoferol y extracto de romero. Se analizaron cinco individuos por dieta cada 3 meses durante 18 meses. El salmón periódicamente se evaluó sensorialmente en estado congelado descongelado y cocido, se analizó apariencia, color, olor y textura en el salmón descongelado y apariencia, color, olor, textura y sabor en salmón cocido. Las propiedades funcionales analizadas fueron capacidad de retención de agua, humedad exprimible, driping, gaping, ensayo de compresión y fuerza de cizalla tanto para el salmón crudo como cocido. Los descriptores sensoriales que presentaron diferencias significativas entre dietas y el tiempo de almacenamiento en el salmón crudo fueron: deshidratación del músculo, color escala Roche, olor típico, olor rancio, olor pútrido, elasticidad y goteo; para el salmón cocido los descriptores fueron: color escala lineal no estructurada, olor típico, olor rancio, sabor típico, sabor rancio, sabor pútrido y sabor oxidado. Estas diferencias no indicaron tendencias definidas entre las dietas estudiadas. Considerando las propiedades funcionales estudiadas, el gaping fue el parámetro determinante de la vida útil comercial del músculo de salmón alimentado con las tres dietas. El gaping de las dietas II y III aumentó paulatinamente sin llegar a un deterioro extremo, manteniendo hasta el mes 15 calidad Premium con grado 3 mientras que, la dieta control solamente alcanzó la calidad premium hasta el mes 9 (p≤0,05). Aunque se registraron diferencias significativas entre los distintos parámetros analizados, se concluye que estas diferencias no afectan la estabilidad del salmón durante el tiempo de almacenamiento, por lo tanto el reemplazo de antioxidantes naturales por antioxidantes sintéticos es viable como mejoramiento en la alimentación del salmón, en la alimentación humana y como una alternativa para mejorar la exportaciones de este producto a las principales regiones donde el salmón tiene una alta demanda.

The reproductive performance of growth-enhanced transgenic and nontransgenic coho salmon (Oncorhynchus kisutch) was examined to address concerns associated with using genetically modified fish in aquaculture. A major concern is the initial reproductive interaction between transgenic and wild fish that may occur if transgenic salmon escape into the natural environment. This thesis attempted to obtain an indication of reproductive allocation, effort and success for transgenic and nontransgenic salmon in a simulated natural environment. Several aspects of reproduction are examined for both transgenic and nontransgenic fish to provide an indication of gamete quantity and quality, courtship behaviour, spawning success, transgene transmission to offspring, and male competitive ability. Female and male body size, shape, and gonadal somatic index (GSI) provided a measure of phenotype and reproductive allocation. Female fecundity and egg diameter, as well as male sperm production, fertility and competition examined gamete quantity and quality. Female digging, probing, and covering, as well as male quivering examined courtship behaviour of ovulated females and ripe males paired together in spawning channels. Spawning success was recorded and fertilized eggs were collected and raised to alevin in order to examine offspring viability. Polymerase chain reactions were conducted on offspring blood samples to determine transgene transmission. Biting, chasing and spawning success of male pairs placed together with an ovulated female were analysed to determine male competitive interactions. Results from these studies found several differences between transgenic and nontransgenic fish. At maturation, transgenic males lacked red coloration and had a less developed kype compared to nontransgenic fish, but no differences in male gamete quantity or quality were observed. Transgenic females were more fecund than nontransgenic females, but may have inferior quality gametes due to reduced egg size. Transgenic females spawned less frequently and displayed consistently low levels of courtship behaviour. No courtship behaviour differences between transgenic and nontrangenic males were observed, however, during competition, transgenic males were inferior; obtaining no spawnings, and displaying less courtship and competitive behaviour. These studies are the first to show that in a simulated natural environment, growth enhanced transgenic coho salmon display courtship behaviour and can spawn producing viable transgenic offspring.

Various aspects of the energetic response to handling stress in juvenile coho salmon (Oncorhynchus kisutch) were examined. Fish were subjected to four different handling stressors in a Blazka-style respirometer. Stressed fish had rates of oxygen consumption that were higher than controls. The magnitude of the increase ranged from 139 to 198% of the control value, and appeared roughly related to the severity of the stressor. The post-stress increase in oxygen consumption also appeared to vary seasonally, with less of a stress effect on respiration observed in the spring as compared to the fall. Elevation in oxygen consumption following stress was largely eliminated within 1 h post-stress, but metabolic rate may have remained slightly elevated for an additional 2 h. Plasma cortisol and lactate titers also increased significantly following handling stressors. Oxygen consumption was positively correlated with both plasma cortisol and lactate after a moderate stressor, but no correlation was found after more severe stressors. Whole body lactate concentration was significantly elevated following stress, reaching levels almost 500% higher than controls. By 5 h post-stress whole body lactate had returned to control levels. The mechanism of excess post-stress oxygen consumption remains unclear. Fish given exogenous cortisol did not experience an increase in oxygen consumption, so it is unlikely that cortisol alone has a major effect on metabolic rate. Similarities between the energetic responses to both stress and exercise suggest that the results of exercise physiology may provide a basis for understanding the energetic response to stress.
Graduation date: 1993

The prevailing view regarding the fitness, evolution and maintenance of male coho mating strategies has been based on pieces of data from different salmon species. Since there is no reason to suppose that all salmon species are the same, there is a need for a quantitative description of male coho salmon breeding behavior. The focus of this thesis is to provide a detailed ethological study of male coho spawning behavior with the objective of quantifying 1) patterns of movements, and 2) interactions among males of different reproductive tactics(alpha, satellite, jack), and breeding groups. Because models that address the evolution and maintanence of reproductive strategies require estimates of tactic fitness for comparison, a secondary objective was to use the quantitative data collected to speculate about costs of reproduction for alternative reproductive tactics. In total, 43 male coho were captured and radio tagged during the 1992 and 1993 spawning escapements in Kanaka Creek. Dominant hooknose males moved within a restricted stream segment (mean daily distance (m) moved 86.33 SE 12.55) accessing the females within the segment. Satellite hooknose males moved both frequently and extensively (mean daily distance (m) moved 661.94 SE 200.13), often entering different waterways during their breeding lifespan. Jack males were found to reside in a small segment of stream throughout their breeding lifespan (mean daily distance (m) moved 46.3 SE 40.3) and made use of a variety of refuges, including the nest itself, from which to 'sneak' fertilizations. Sixty-two breeding groups were identified, each having a anywhere from one to five male group members. Rates of aggressive interactions (mean interactions per 10 minutes) were found to differ significantly among males adopting different reproductive tactics (P < 0.001). Alpha males had the highest rate of aggressive interactions (15.2 SE 2.9 ) compared to alternative male behaviors (first satellite 4.7 SE 0.9, second satellite 5.7 SE 1.3, and jack 2.4 SE 0.9). Aggression levels were found to differ significantly among mating groups ( 0.01 > P > 0.025). Intermediate size groups had the lowest aggression level, 11.57 SE 3.81 int/10 min (2 males) and 13.49 SE 3.87 int/10 min (3 males). The highest level of competitive interactions occurred when only one male and one female were present (29.05 SE 12.50 int/10 min). Pairs of combatants explained the increasing rate of aggression with group size for groups containing more than one reproductive tactic (2 to 5 males)(0.75