Journal articles: 'Larval stage'

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Einer, H., and E. Ellegård. "Nasal myiasis by Oestrus ovis second stage larva in an immunocompetent man: case report and literature review." Journal of Laryngology & Otology 125, no. 7 (May 24, 2011): 745–46. http://dx.doi.org/10.1017/s002221511100096x.

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AbstractObjective:We report a case of an Oestrus ovis larva which developed into the second larval stage within a healthy, immunocompetent human, and we review the relevant literature.Methods:Clinical case report and Pubmed search of reports of human nasal myiasis due to Oestrus ovis, especially those describing the larval stage.Results:Humans are not normally hosts of the sheep nasal bot fly, but infestations by its larvae have been described. The eye is the most common site, but larvae have occasionally been found in the human nose. Transformation of larvae into the second and third stages, within the human nose, is even more uncommon.Conclusion:To the best of our knowledge, we report the first Swedish case, and the third case world-wide, of Oestrus ovis larval development beyond the first larval stage, within an immunocompetent, healthy human.

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Rötzer, Marie A. I. N., and Joachim T. Haug. "Larval Development of the European Lobster and How Small Heterochronic Shifts Lead to a More Pronounced Metamorphosis." International Journal of Zoology 2015 (2015): 1–17. http://dx.doi.org/10.1155/2015/345172.

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We redescribe the larval stages of the European lobster,Homarus gammarus, based on autofluorescence composite imaging. We focus on larval stages (II) to (IV). Compared to the American lobster,Homarus americanus, differences are most apparent in stage (III). This stage appears more mature inH. gammarus; for example, the rostrum is already curved and bears spines, and the appendages are better developed and longer and more differentiated. InH. americanusstage (III) shows a stronger resemblance to stage (II). As a result of the morphology of stage (III), the “metamorphic” moult between stage (III) and stage (IV) inH. gammarusis less drastic than inH. americanus. Metamorphosis is characterised by two criteria. It involves (1) a drastic change in morphology in (2) a short amount of time. It has hence been suggested that a more pronounced metamorphosis evolves by two factors affecting these criteria, namely, (1) the evolution of specialised larval features, which increase the morphological disparity between larva and adult that makes the change of morphology more drastic, and (2) the skipping of entire stages. This means larval forms ancestrally moult over several intermediate forms into the definite adult morphology. Yet, in more derived forms the stages with intermediate morphologies are no longer expressed; highly specialized larvae moult into the adult within a single moult (in the most extreme case) hence bridging the morphologies of larvae and adult in a shorter amount of time. The example of the twoHomarusspecies demonstrates that this explanation is not the only possible one. Additionally, differences of a single larval stage (in this case larval stage (III)) can lead to a more or less metamorphic-appearing ontogenetic sequence.

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Mulyana, Jeane Siswitasari, Achmad Farajallah, and Yusli Wardiatno. "Redescription of Larval Development in Cultured Pearl Oyster Pinctada maxima." ILMU KELAUTAN: Indonesian Journal of Marine Sciences 23, no. 2 (June 21, 2018): 109. http://dx.doi.org/10.14710/ik.ijms.23.2.109-112.

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Larval development plays a major role in efficient pearl culture. The cultured larvae will be later used for recipient and donor oysters in cultured pearl production. Larval developmental stage of silver lip pearl oyster Pinctada maxima has been reported by several studies. Those studies used female and male oyster parents directly taken from natural habitat.This study aimed to redescribe larval development of P. maxima from commercial pearl oyster culture farm in Indonesia. Larval development of this species whose parents are originated from selected groups in the pearl culture farm has not been reported yet, thus it is necessary to be described. This species undergoes specific larval developmental stage. The larvae were observed under microscope, and then the average shell length (SL) and shell height (SH) were measured. D-shaped veliger larva (77.4±0.3 µm SL; 65.4±1.1 µm SH) appeared 20 h after fertilization. Tenday-old larva (156.2±2.8 µm SL; 149.5±5.6 µm SH) had developed umbo region so it was called umbonal larva. Umbonal larva then developed further into plantigrade larva (411.3±9.8 µm SL; 380.5±6.9 µm SH) in 25 days after fertilization. Developmental stage and larval sizein P. maxima is similar with those observed in P. fucata and P. margaritifera. Keywords: growth, larva, plantigrade, shell, umbo, veliger

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Rye, Leslie A., and Michael R. Baker. "The life history of Hysterothylacium analarum Rye and Baker, 1984 (Nematoda: Anisakidae) in Lepomis gibbosus (Pisces: Centrarchidae) in southern Ontario, Canada." Canadian Journal of Zoology 70, no. 8 (August 1, 1992): 1576–84. http://dx.doi.org/10.1139/z92-217.

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Larval stages of Hysterothylacium analarum are described from Lepomis gibbosus in Dawson Pond, Ontario (45°10′N, 78°50′W). Second-stage larvae were easily distinguished from all other stages by the presence of a conical boring tooth. Third-stage larvae lacked both a boring tooth and lips. Fourth-stage larvae had well-developed lips. The ratio of ventricular appendage length to intestinal caecum length varied greatly between larval stages and adults. Prevalence and intensity of larval stages and adult H. analarum showed a distinct seasonal pattern, with one generation of adult worms per year. In spring, third-stage larvae left nodules on the intestinal serosa of L. gibbosus and migrated to the intestinal lumen, where they rapidly moulted to the fourth-stage and then to adult worms. Eggs collected from gravid females developed to second stage larvae in approximately 5 days under laboratory conditions. In natural infections in the late summer second-stage larvae were found in nodules on the serosa and in the mesentery. Larvae apparently moulted to the third stage and overwintered in the nodules as third-stage larvae.

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Watanabe, H., R. Kado, S. Tsuchida, H. Miyake, M. Kyo, and S. Kojima. "Larval development and intermoult period of the hydrothermal vent barnacle Neoverruca sp." Journal of the Marine Biological Association of the United Kingdom 84, no. 4 (August 2004): 743–45. http://dx.doi.org/10.1017/s0025315404009841h.

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Larvae of the hydrothermal vent barnacle Neoverruca sp. were reared under laboratory conditions and larval development was observed. Under these conditions, the larvae were released from adults as first-stage nauplii, although the larvae of other deep-sea barnacles have generally been considered to be released at a later larval stage such as the cyprid stage. The larvae of Neoverruca sp. were lecithotrophic through six naupliar stages and the subsequent cyprid stage. The larval period of Neoverruca sp. was more than 96 days under the present rearing conditions, which is the longest yet reported for barnacles. Most cyprid larvae, however, exhibited abnormal morphology and no larvae settled successfully on the substrate. These observations suggest that such a long larval period might enable neoverrucid barnacles to disperse between vent fields.

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XU, TIAN, CHAOSHU ZENG, and KATE S. HUTSON. "Morphological descriptions of the larval and first juvenile stages of the decorator crab Camposcia retusa (Latreille, 1829) from laboratory-reared material." Zootaxa 4577, no. 2 (April 5, 2019): 295. http://dx.doi.org/10.11646/zootaxa.4577.2.4.

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The complete larval and first crab stages of the decorator crab Camposcia retusa (Latreille, 1829) are described and illustrated based on laboratory-reared material for the first time. Specimens were obtained from larvae hatched from adult crabs collected from coral reefs of Queensland, Australia. Newly hatched larvae were successfully reared to settlement as the first-stage crabs. Larval development consisted of two zoeal stages and one megalopal stage. The morphology of each larval stage was compared with those available from a previous study using material from the Red Sea. Due to substantial differences in morphology of the second zoeal and megalopal stages between the two studies, we argue that these larval stages described by the earlier report may not be that of C. retusa. Finally, the morphological characters of both larval and first crab stages of C. retusa are also compared with the corresponding stages of previously reported Inachidae.

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ANASTASIADOU, CHRYSSA, ALEXANDROS NTAKIS, and IOANNIS D. LEONARDOS. "Larval development of the freshwater shrimp Atyaephyra desmarestii (Millet, 1831) sensu lato (Decapoda: Caridea: Atyidae) and morphological maturation from juveniles to adults." Zootaxa 2877, no. 1 (May 13, 2011): 41. http://dx.doi.org/10.11646/zootaxa.2877.1.2.

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A complete serial of larval staging of Atyaephyra desmarestii (Millet, 1831) sensu lato from Louros River (north-western Greece) was obtained in the laboratory and described in detail. Thirty berried females were collected and transferred to an aquarium containing water and vegetation from the sampling site. The newly hatched larvae were transferred into small sterile aquaria and mass cultured. After each moult, several larvae were photographed and preserved with their exuviae. The reared larvae of A. desmarestii sensu lato passed through six zoeal stages and one megalopal stage. At the experimental conditions, the durations of each larval stage were as follows: three days for the 1 st larval stage; three to four days for 2 nd larval stage; six to eight days for 3 rd ; seven to nine days for 4 th ; nine to ten days for 5 th , 6 th and megalopal stages. All the obtained stages were described in detail. The larval morphological characters of the described material and the larvae specimens collected from natural populations were compared with the literature data on closely related species. Morphological description of the different phases for juveniles, immature, female and male mature individuals of A. desmarestii sensu lato are also presented in detail.

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Abrunhosa, Fernando A., Darlan J. B. Simith, Joely R. C. Monteiro, Antonio N. de Souza Junior, and Pedro A. C. Oliva. "Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil." Anais da Academia Brasileira de Ciências 83, no. 4 (October 21, 2011): 1269–78. http://dx.doi.org/10.1590/s0001-37652011005000045.

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Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both . vocator and P occidentalis need an external food source before completing the larval development in a planktonic environment.

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Duneau, David F., and Brian P. Lazzaro. "Persistence of an extracellular systemic infection across metamorphosis in a holometabolous insect." Biology Letters 14, no. 2 (February 2018): 20170771. http://dx.doi.org/10.1098/rsbl.2017.0771.

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Organisms with complex life cycles can differ markedly in their biology across developmental life stages. Consequently, distinct life stages can represent drastically different environments for parasites. This difference is especially striking with holometabolous insects, which have dramatically different larval and adult life stages, bridged by a complete metamorphosis. There is no a priori guarantee that a parasite infecting the larval stage would be able to persist into the adult stage. In fact, to our knowledge, transstadial transmission of extracellular pathogens has never been documented in a host that undergoes complete metamorphosis. We tested the hypothesis that a bacterial parasite originally sampled from an adult host could infect a larva, then survive through metamorphosis and persist into the adult stage. As a model, we infected the host Drosophila melanogaster with a horizontally transmitted, extracellular bacterial pathogen, Providencia rettgeri . We found that this natural pathogen survived systemic infection of larvae (L3) and successfully persisted into the adult host. We then discuss how it may be adaptive for bacteria to transverse life stages and even minimize virulence at the larval stage in order to benefit from adult dispersal.

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Zavala-Leal, I., S. Dumas-Lapage, and R. Peña-Martinez. "ORGANOGÉNESIS DURANTE EL PERIODO LARVAL EN PECES." CICIMAR Oceánides 26, no. 2 (December 4, 2011): 19. http://dx.doi.org/10.37543/oceanides.v26i2.100.

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La presencia de un periodo larval caracteriza a los peces con ontogenia indirecta. Este periodo de desarrollo implica una serie de transformaciones encaminadas a la adquisición de las características biológicas y ecológicas propias de la especie; y en muchos casos culmina con cambios de distribución y hábitos alimenticios. El periodo larval incluye cuatro estadios de desarrollo: larva vitelina, larva pre-flexión, larva flexión y larva post-flexión. Cada estadio de desarrollo presenta características asociados a cambios en las diferentes prioridades durante el crecimiento. De esta forma, durante los estadios de larva vitelina y larva pre-flexión, la prioridad es incrementar las posibilidades de supervivencia a través de enfatizar la capacidad alimenticia y de evasión de depredadores, lo cual se ve reflejado en una mayor diferenciación de estructuras asociadas a estas funciones. La larva flexión se caracteriza por presentar un mayor grado de funcionalidad de los órganos y estructuras desarrolladas anteriormente. Finalmente, durante el estadio de larva post-flexión se presentan los cambios más agudos con respecto a la funcionalidad de los órganos ya desarrollados. En el presente trabajo se realiza la descripción del desarrollo de estos órganos para cada uno de los estadios de desarrollo larval, haciendo referencia en las diferencias y semejanzas entre distintas especies de importancia comercial. Organogenesis during the larval period in fishes The presence of a larval period is characteristic of fishes with an indirect ontogeny. Many transformations involved in this period lead to the acquisition of biological and ecological characteristics of each species, that culminate in changes in distribution and feeding habits. Larval period includes four developmental stages: viteline larvae, pre-flexion larvae, flexion larvae and post-flexion larvae. Each developmental stage showed inherent characteristics associated with changes in priorities during growth. During the viteline larvae and pre-flexion larval stages, priority is about increasing the survival possibility through an increase in the capacity of feeding and escaping predators which is reflected in the development of structures involved in these activities. The flexion larva is characterized by a greater degree of functionality of organs and structures previously developed. Finally, the post-flexion larvae show the most drastical changes in the functionality of developed organs. In this work, we present a description of the development of these organs, taking into account differences and similarities between species.

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Polte, Patrick, Paul Kotterba, Cornelius Hammer, and Tomas Gröhsler. "Survival bottlenecks in the early ontogenesis of Atlantic herring (Clupea harengus, L.) in coastal lagoon spawning areas of the western Baltic Sea." ICES Journal of Marine Science 71, no. 4 (May 22, 2013): 982–90. http://dx.doi.org/10.1093/icesjms/fst050.

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Abstract Dominant drivers of larval survival are considered to include oceanographic dispersal, sea temperatures, and food availability in the phase of first-feeding. However, research progress on larval herring survival dynamics indicates that multiple factors might act on differing larval developmental stages. Hypothesizing that in inshore systems of the western Baltic Sea bottlenecks of herring development occur before the point of first-feeding, we analysed an extensive time-series of weekly abundances of early stage larvae in Greifswald Bay, an important spawning area for Western Baltic herring. Additionally, we investigated whether distinct hatching cohorts contribute differently to established survival indices on the level of (i) later larval stages in Greifswald Bay and (ii) 1+ group juveniles in the overall western Baltic Sea. Results revealed that abundances of the earliest larval stage explain 62% of the variability of later stage larvae and 61% of the variability of surviving juveniles, indicating pre-hatching survival bottlenecks. Hatching cohorts occurring later during the spawning season contribute most to the surviving year class. Earlier hatching cohorts were not found to result in significant amounts of growing larvae, indicating a bottleneck phase at the critical period when larvae start feeding.

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Winch, Judith M., and J. Riley. "Studies on the behaviour, and development in fish, ofSubtriquetra subtriquetra: a uniquely free-living pentastomid larva from a crocodilian." Parasitology 93, no. 1 (August 1986): 81–98. http://dx.doi.org/10.1017/s0031182000049842.

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SUMMARYThe primary larva of the porocephalid pentastomidSubtriquetra subtriquetra, which infects the nasopharynx ofCaiman sclerops, is uniquely free-living. Eggs hatch within the nasal passages and the emergent larvae can remain infective to the fish intermediate host for 4–5 days. During this period larvae exhibit very stereotyped behaviour, alternating between a characteristic stationary ‘fishing’ posture and very brief periods of movement. Larval activity increases significantly at 3 days, probably effecting dispersal to a more favourable site for host invasion. Host location is passive and invading larvae penetrate to the swim-bladder where subsequent larval development, which involves 7 moults, occurs. All 8 larval stages are freely mobile in the swim-bladder and possess hooks. Sensilla, disposed in characteristic patterns, are present throughout development, increasing in number to the infective stage; the majority of sensilla are located on sensory papillae.

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CARVALHO, Thaís Billalba, Ellen Cristina Monteiro de SOUZA, Jaquelinne PINHEIRO-DA-SILVA, and Marle Angélica VILLACORTA-CORREA. "Effect of body size heterogeneity on the aggressive behavior of larvae of matrinxã, Brycon amazonicus (Characiformes, Bryconidae)." Acta Amazonica 48, no. 4 (December 2018): 304–10. http://dx.doi.org/10.1590/1809-4392201800541.

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ABSTRACT Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.

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Ouellet, Patrick, Denis Lefaivre, and Vladimir Koutitonsky. "Distribution of Shrimp (Pandalus borealis) Larvae and Hydrographic Pattern in the Northern Gulf of St Lawrence." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 11 (November 1, 1990): 2068–78. http://dx.doi.org/10.1139/f90-231.

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The large-scale spatial distribution of northern shrimp (Pandalus borealis) larvae was analyzed in the Gulf of St. Lawrence during the spring of 1986 and 1987. Although sites of emergence are related to the principal aggregation areas of adult shrimp, it appears that the currently fished aggregations may not represent isolated populations. The uniformity of developmental stages and the wide-spread distribution of the first larval stage were consistent with the hypothesis of synchronous larval emergence among the northern Gulf shrimp The structured pattern of larval spatial distribution was not correlated with the hydrographic structure within the different sectors of the Gulf (Mantel test; P > 0.05). Spatial correlograms showed that the highly structured spatial distribution pattern of stage I larvae evolved into a spatially random pattern by the time stage III larvae had developed. We suggest that biological or ecological dynamic processes such as larval mortality and development rates are more important than the hydrodynamics of the sectors in determining the structure of larval shrimp distribution Consequently, on a seasonal basis, the distribution of larval shrimp groups cannot be inferred from a study of the hydrographic pattern within the sectors at the scale of our analysis.

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Ndao, Papa Demba, Justin Kantoussan, Momy Seck, Nicolas Jouanard, Amit Alkaly Savaya, Raphael Abdoulaye Ndione, and Omar Thiom Thiaw. "Breeding and larval rearing in hatchery of Macrobrachium vollenhovenii (Herklots, 1857) in a perspective of biological control against human Schistosomiasis in tropical area." Journal of Marine Biology and Aquaculture 5, no. 1 (May 12, 2019): 1–9. http://dx.doi.org/10.15436/2381-0750.19.2019.

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As part of an effort to use biological control against human schistosomiasis, post-larval production of the prawn Macrobrachium vollenhovenii was carried out in a hatchery. This species is a freshwater native and is fond of mollusks, intermediate hosts of schistosomes that transmit human diseases in the wild. The larval production of this species occurred in six (06) tanks - two 200 L and four 600 L. The management of brood stock took place in fresh water, with a ratio of one male to four females. Each fertilized female produced thousands of eggs attached to the abdomen until hatching about two weeks later. The larvae resulting from this reproduction were raised to the post-larval stage in brackish water at a salinity of 15 ppt. The larvae must undergo a molt between each stage. We identified 15 morphological stages between stage 1 and the post-larval stage. The duration from stage 1 until onset of the first post-larval stage in the six (06) tanks was on average 54 days after hatching. The success of larvi culture is defined by the rate of metamorphosis of the larvae into post-larvae, which, in our case, varied between 0.17% and 3.08%, depending on the production tanks, with an average of 2.8%. These results show that the production of M. vollenhovenii in hatchery is possible, presenting a possibility for aquaculture production of this species as well as for biological control against schistosomiasis in a tropical area

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López, C., R. Panadero, P. Díez, and P. Morrondo. "Development of Neostrongylus linearis in Cernuella (Cernuella) virgata experimentally infected and maintained in the subhumid climate of Galicia in northwest Spain." Journal of Helminthology 71, no. 3 (September 1997): 211–16. http://dx.doi.org/10.1017/s0022149x00015935.

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AbstractTwelve batches of the mollusc Cernuella (Cernuella) virgata (Mollusca: Helicidae) were deposited monthly directly on faeces containing first-stage larvae of Neostrongylus linearis, so that they were naturally infected. Every two weeks the molluscs were examined to study the larval development of N. linearis. No correlation was found between the number of first-stage larvae of N. linearis on the faeces and the number of total larvae and third-stage larvae which developed in the snails. However, a negative correlation was found between temperature and the days needed to reach the different larval stages. Thus, the molluscs harboured third-stage larvae from mid-spring to mid-autumn, the period of time which carries the greatest risk of infection for the definitive hosts.

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Hudon, Christiane, and Pierre Fradette. "Wind-Induced Advection of Larval Decapods into Baie de Plaisance (Îles de la Madeleine, Québec)." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 7 (July 1, 1993): 1422–34. http://dx.doi.org/10.1139/f93-163.

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Abundance and spatial distribution of the larvae of the American lobster (Homarus americanus), the common rock crab (Cancer irroratus), and the toad crab (Hyas spp.), were monitored weekly during the summer of 1980 at a grid of 12 stations located in Baie de Plaisance. Following a period of winds ≥ 30 km∙h−1 shifting from the north to the southeast, large numbers of late-stage larvae of the three species were advected in the bay, concurrently with an intrusion of low-salinity water. Weekly abundances of consecutive larval stages were highly correlated, indicating that larvae tended to remain in the same water mass. Spatial association tended to be highest among the early stages within each species. The late larval stages of both lobster and rock crab behaved differently from the early stages with respect to light intensity and their horizontal distribution. Although the advection of water masses under the influence of wind events determines the overall abundance of larval decapods in Baie de Plaisance, larval behaviour (vertical migration and swimming ability) also affected distribution of older stage larvae but at a smaller scale. The dependence of advection on sporadic wind events occurring at the time of peak larval abundance reduces the chances of modelling yearly recruitment using average summer climatic conditions.

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Wakabayashi, Kaori, and Bruce F. Phillips. "Morphological descriptions of laboratory reared larvae and post-larvae of the Australian shovel-nosed lobster Thenus australiensis Burton & Davie, 2007 (Decapoda, Scyllaridae)." Crustaceana 89, no. 1 (2016): 97–117. http://dx.doi.org/10.1163/15685403-00003511.

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Complete larval development from newly hatched larvae up to the juvenile stage was successfully achieved in the Australian shovel-nosed lobsterThenus australiensisunder laboratory conditions. The larvae of this species passed through four phyllosoma stages (each stage has a single instar), and developed into the first juvenile stage via a post-larval, nisto stage. The shortest and mean durations from hatching to metamorphosis at a water temperature of 25°C were 32 and 38 days, respectively. Morphologies of body and appendages for all four phyllosoma stages and the nisto stage were described. The phyllosomas were fed exclusively on the jellyfishAurelia auritathroughout their culture. Our results indicate that jellyfish may be a viable diet forT. australiensisphyllosoma’s in culture and may therefore be useful for commercial-scale lobster production.

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Køie, Marianne, Bjørn Berland, and Michäel D. B. Burt. "Development to third-stage larvae occurs in the eggs of Anisakis simplex and Pseudotetranova decipiens (Nematoda, Ascaridoidea, Anisakidae)." Canadian Journal of Fisheries and Aquatic Sciences 52, S1 (August 1, 1995): 134–39. http://dx.doi.org/10.1139/f95-519.

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Two moults occur during larval development in the eggs of Anisakis simplex (Rudolphi, 1809) and Pseudoterranova decipiens (Krabbe, 1878) from the North Atlantic. Live larvae forced out of eggs in sea water by coverslip pressure shortly before spontaneous hatching were surrounded by the thin cuticle of the first-stage larva. Infective larvae from naturally hatched eggs are loosely ensheathed in the thick cuticle of the second-stage larva. Thus, it is the third-stage larva that emerges from the egg of both species and not the second-stage larva as previously believed. The thin, smooth, fragile cuticle of the first-stage larva remains in the egg. The striated, cocoon-like cuticle of the second-stage larva of A. simplex may increase the buoyancy of the third-stage larva. The tail tip of the cuticle of the second-stage larva of P. decipiens is sticky and adheres the sheathed third-stage larva to the substrate.

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Tyrrell, Jordan J., Jackson T. Wilbourne, Alisa A. Omelchenko, Jin Yoon, and Lina Ni. "Ionotropic Receptor-dependent cool cells control the transition of temperature preference in Drosophila larvae." PLOS Genetics 17, no. 4 (April 7, 2021): e1009499. http://dx.doi.org/10.1371/journal.pgen.1009499.

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Temperature sensation guides animals to avoid temperature extremes and to seek their optimal temperatures. The larval stage of Drosophila development has a dramatic effect on temperature preference. While early-stage Drosophila larvae pursue a warm temperature, late-stage larvae seek a significantly lower temperature. Previous studies suggest that this transition depends on multiple rhodopsins at the late larval stage. Here, we show that early-stage larvae, in which dorsal organ cool cells (DOCCs) are functionally blocked, exhibit similar cool preference to that of wild type late-stage larvae. The molecular thermoreceptors in DOCCs are formed by three members of the Ionotropic Receptor (IR) family, IR21a, IR93a, and IR25a. Early-stage larvae of each Ir mutant pursue a cool temperature, similar to that of wild type late-stage larvae. At the late larval stage, DOCCs express decreased IR proteins and exhibit reduced cool responses. Importantly, late-stage larvae that overexpress IR21a, IR93a, and IR25a in DOCCs exhibit similar warm preference to that of wild type early-stage larvae. These data suggest that IR21a, IR93a, and IR25a in DOCCs navigate early-stage larvae to avoid cool temperatures and the reduction of these IR proteins in DOCCs results in animals remaining in cool regions during the late larval stage. Together with previous studies, we conclude that multiple temperature-sensing systems are regulated for the transition of temperature preference in fruit fly larvae.

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Kizhakudan, Joe K., and S. Krishnamoorthi. "Complete larval development of Thenus unimaculatus Burton & Davie, 2007 (Decapoda, Scyllaridae)." Crustaceana 87, no. 5 (2014): 570–84. http://dx.doi.org/10.1163/15685403-00003306.

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Larval development of the shovel-nosed lobster Thenus unimaculatus Burton & Davie, 2007 is described based on laboratory studies. The larval stages included four stages of phyllosoma (I-IV), followed by a post larval, non-feeding nisto stage which metamorphosed to the juvenile stage, also known as first seed. The nisto stage is reached in 26-30 days, the average duration of each phyllosoma (I-IV) and nisto was 7, 5, 7, 7 and 4 days, respectively. The phyllosomas are characteristically flattened, leaf-like, transparent planktonic larvae, while the nisto, translucent in appearance, remains sedentary at the bottom. The first juvenile stage has a hard exoskeleton and feeds on fresh clam meat. The survival rate from phyllosoma I to nisto was 22%.

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Gravinese, Philip M., Ian C. Enochs, Derek P. Manzello, and Robert van Woesik. "Ocean acidification changes the vertical movement of stone crab larvae." Biology Letters 15, no. 12 (December 2019): 20190414. http://dx.doi.org/10.1098/rsbl.2019.0414.

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Anthropogenic activities are increasing ocean temperature and decreasing ocean pH. Some coastal habitats are experiencing increases in organic runoff, which when coupled with a loss of vegetated coastline can accelerate reductions in seawater pH. Marine larvae that hatch in coastal habitats may not have the ability to respond to elevated temperature and changes in seawater pH. This study examined the response of Florida stone crab ( Menippe mercenaria ) larvae to elevated temperature (30°C control and 32°C treatment) and CO 2 -induced reductions in pH (8.05 pH control and 7.80 pH treatment). We determined whether those singular and simultaneous stressors affect larval vertical movement at two developmental stages. Geotactic responses varied between larval stages. The direction and rate of the vertical displacement of larvae were dependent on pH rather than temperature. Stage III larvae swam upwards under ambient pH conditions, but swam downwards at a faster rate under reduced pH. There was no observable change in the directional movement of Stage V larvae. The reversal in orientation by Stage III larvae may limit larval transport in habitats that experience reduced pH and could pose challenges for the northward dispersal of stone crabs as coastal temperatures warm.

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Stoeckel, James A., Dianna K. Padilla, Daniel W. Schneider, and Chris R. Rehmann. "Laboratory culture of Dreissena polymorpha larvae: spawning success, adult fecundity, and larval mortality patterns." Canadian Journal of Zoology 82, no. 9 (September 1, 2004): 1436–43. http://dx.doi.org/10.1139/z04-125.

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Understanding the entire life history, especially critical periods during the life cycle of a species, is important for understanding population dynamics and is crucial for control of nuisance species. Errors in estimates of growth rates and recruitment in field and modeling studies are likely to occur if one assumes uniform rather than size- or stage-specific mortalities for larval stages. Similarly, effects of brood-stock health on adult fecundity and larval mortality patterns might affect results of laboratory studies investigating larval life history. We maintained zebra mussels, Dreissena polymorpha (Pallas, 1771), in spawning condition in the laboratory for 24 weeks. Healthy larvae were produced for 18 weeks. However, induction of spawning and egg production declined through time. Fecundity increased with size per female, but sperm production did not for males. We found no correlation between clutch size and egg size across a wide range of clutch sizes. Survivorship was greater when larvae were reared at lower densities. Daily larval mortality was strongly size dependent; the average size of dead larvae was similar to the minimum size of live larvae. Highest daily larval mortality occurred during the transition from D stage to umbonal stage, supporting the suggestion of a developmental bottleneck as found in previous field studies.

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Wehrtmann, Ingo S., and Luis Albornoz. "Larvae of Nauticaris magellanica (Decapoda: Caridea: Hippolytidae) reared in the laboratory differ morphologically from those in nature." Journal of the Marine Biological Association of the United Kingdom 83, no. 5 (September 19, 2003): 949–57. http://dx.doi.org/10.1017/s0025315403008130h.

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The variability of larval morphology in the caridean shrimp Nauticaris magellanica cultivated in the laboratory was analysed, and its applicability for the identification of larval stages collected from the plankton evaluated. Both morphometric and meristic variability of selected appendages was analysed comparing larvae from the rearing experiment with those obtained from the plankton. Larval development in the laboratory consisted of at least nine zoeal and five decapodid stages, followed by the first juvenile stage. Larvae collected from the plankton, comprising individuals from zoea II to, presumably, zoea VIII, were generally more developed and had a larger size than the corresponding stages reared in the laboratory. Cultured larvae showed a high exophenotypical variability starting with zoea IV, which impeded an immediate determination of larval stages obtained from the plankton.

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25

Hudon, Christiane, and Pierre Fradette. "Planktonic Growth of Larval Lobster (Homarus americanus) off îles de la Madeleine (Quebec), Gulf of St. Lawrence." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 5 (May 1, 1988): 868–78. http://dx.doi.org/10.1139/f88-105.

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The carapace length of the three planktonic larval and one postlarval stages of Homarus americanus was measured for larvae collected off îles de la Madeleine over three summers. Mean larval size did not vary between years or locations around the islands. The size of stages I and II remained constant throughout the summer, but after molting into stages III and IV, larvae diminished in size through the summer. Size frequency distribution became more scattered as larvae grew into more advanced stages. The increase of variance with size between stages I–IV followed the same progression as that observed between stages V–XIII, allowing prediction of the variance associated with mean size at each stage. The size of stage I larvae collected in nine regions along the Atlantic coast was not correlated with the July surface water temperature or with the smallest female size at maturity. Comparison of various body proportions suggested that a single morphometric measurement is not sufficient to describe geographical variations in size. Percentage growth per molt decreased with each successive molt. During summer, increment at molt decreased and molt frequency increased. Larval growth rates followed closely the temperature regime, with maximum growth rate attained during the warmest period of the summer (July 30 – August 9). The duration of the first three larval stages estimated from field data was of 24 d compared with 21 d calculated from previous laboratory studies. The maximum abundance of stage I larvae was synchronized with the period of most rapid increase in summer temperature, thus insuring that larvae achieved highest net growth rates through their planktonic phase.

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Nasrolahi, Ali, Alireza Sari, Seyedjafar Saifabadi, and Masoumeh Malek. "Effects of algal diet on larval survival and growth of the barnacle Amphibalanus (=Balanus) improvisus." Journal of the Marine Biological Association of the United Kingdom 87, no. 5 (October 2007): 1227–33. http://dx.doi.org/10.1017/s0025315407057037.

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The effects of algal diet on larval survival and growth of the barnacle Amphibalanus improvisus was for the first time examined under controlled laboratory conditions. Larvae were obtained by dissecting egg lamellae at later developmental stage out of the adults. Hatched nauplii were reared in 0.6-l glass beakers (200 larvae l-1) on a monoalgal diet of Chaetoceros calcitrans, Chlorella vulgaris and Scenedesmus quadricauda at 1x105 and 2x105 cells ml-1, under continuous light at 25 ±1°C. The rate of development, survival and size (at Stage V) of the larvae were measured for each diet. The majority of nauplius II larvae (~70%) fed with Cha. calcitrans and Chl. vulgaris developed into cyprids within seven days while those fed with S. quadricauda remained at Stage II. A shorter time interval for Stage II to III was observed in larvae fed with a Chl. vulgaris monoalgal diet than Cha. calcitrans. Larvae fed with Cha. calcitrans had shorter developmental intervals for later larval stages (Stages IV–VI). The highest mortality was observed in the treatment with a monoalgal diet of S. quadricauda, while the highest survival was achieved with a diet of Cha. calcitrans. The mixed diet of Cha. calcitrans, Chl. vulgaris and S. quadricauda resulted in a shorter developmental duration of larval cycle (six days). Both food type and food concentration significantly affected the length and width of the nauplius larvae.

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Hudon, Christiane, Pierre Fradette, and Pierre Legendre. "La répartition horizontale et verticale des larves de homard (Homarus americanus) autour des îles de la Madeleine, golfe du Saint-Laurent." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 11 (November 1, 1986): 2164–76. http://dx.doi.org/10.1139/f86-265.

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Thirty-nine stations localized around the eastern tip of the Îles de la Madeleine, in two lagoons, and in the baie de Plaisance were sampled using plankton net tows during the summers of 1978, 1980, and 1981. The horizontal and vertical distributions of each of the four larval stages of Homarus americanus were assessed from sets of surface tows using simple neuston and meter nets (1978 and 1980) as well as a three-compartment plankton net (1981). Most of the stage I larval production takes place in the northeast and southeast regions. However, the abundance of stage IV larvae is low in the southeast and almost nil in the northeast. By contrast, the baie de Plaisance harbors very few stage I larvae, but a very high proportion of stage III and IV larvae. The periods of first appearance and maximum abundance are also out of phase for the three regions, occurring in the northeast before the southeast and the baie de Plaisance. These results suggest that the general pattern of abundance of larvae is driven by the current regime, flushing the larvae around the Pointe de l'Est and concentrating them in the baie de Plaisance following a gyre. On a smaller scale, 12 stations arranged in a 3 × 4 grid in the baie de Plaisance were sampled for 12 wk in the summer of 1980. The first three larval stages show a strongly aggregated distribution and are most frequent at the mouth of the bay. Conversely, stage IV larvae are found more frequently in the shore stations and inside the bay. There is a significant correlation between stage IV larval abundance and the distance to rocky bottoms favorable to benthic life. The vertical distribution of larvae at two stations (1981) shows that only the stage I larvae have a vertical distribution related to light intensity, being found in highest abundance in the surface layer (0–0.8 m) at dusk and dawn. Stage I larvae were uniformly distributed between 0 and 1.6 m during the day and down to 2.4 m at night. Stage II, III, and IV larvae were always found near the surface.

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SATAR, ALİ, ZEKİYE SULUDERE, SAVAŞ CANBULAT, and CENGİZHAN ÖZBAY. "Rearing the larval stages of Distoleon tetragrammicus (Fabricius, 1798) (Neuroptera: Myrmeleontidae) from egg to adult, with notes on their behaviour." Zootaxa 1371, no. 1 (December 4, 2006): 57. http://dx.doi.org/10.11646/zootaxa.1371.1.5.

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Eggs of the ant-lion Distoleon tetragrammicus (Fabricius, 1798) were obtained from gravid females for the first time. Larvae were reared to the adult stage from eggs. The eggs and the different parts of the larva such as head, mandibles and antennae, are described and illustrated and larval behavior in each stage was monitored.

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Egan, EA, and DT Anderson. "Larval development of Elminius covertus Foster and Hexaminius popeiana Foster (Cirripedia : Archaeobalanidae : Elminiinae) reared in the laboratory." Marine and Freshwater Research 36, no. 3 (1985): 383. http://dx.doi.org/10.1071/mf9850383.

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The presence of embryos in the mantle cavity of E. covertus and H. popeiana has been monitored over a 2-year period. E. covertus has a clearly defined seasonal pattern with peak breeding during the winter and early spring. H. popeiana shows high levels of breeding activity throughout the year. The larval stages of E. covertus and H. popeiana are described from larvae reared in the laboratory. Morphological differences in each larval stage allow the larvae of the two species to be distinguished without difficulty. Differences between the larval stages of E. covertus and E. modestus are more minor, but are sufficient to distinguish most stages. Similarities in the larval morphology of the genera Elminius and Hexaminius support their inclusion in the subfamily Elminiinae. The larvae of H. popeiana also share features with the larvae of archaeobalanines, especially Conopea galeata.

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Ronquillo, Jesse D., and Toshio Saisho. "Larval development of Metapenaeopsis barbata (de Haan, 1844) (Crustacea: Decapoda: Penaeidae)." Marine and Freshwater Research 48, no. 5 (1997): 401. http://dx.doi.org/10.1071/mf93077.

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Gravid females of Metapenaeopsis barbata spawned in the laboratory by natural means and the larvae were reared from hatching to postlarval stage at 27·0–29·8˚C and 33·5–34·5 g kg -1 salinity. The larvae metamorphosed into first postlarvae, with a survival rate of up to 98·4%, after about 10 days following hatching and subsistence on only an algal diet of Tetraselmis tetrathele and Chaetoceros gracilis. Six naupliar stages, three protozoeal stages, three mysis stages and the first postlarval stage are described and illustrated. On the basis of morphological characteristics, larval stages of M. barbata can be distinguished from similar stages of closely related species in the family Penaeidae. As inferred from the morphology of the larval feeding apparatus, M. barbata is still a filter-feeder even at the first postlarval stage.

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Benítez, Sergio A., Thomas M. Iliffe, Salvador Martínez, Juan Carlos Ojeda, José Luis Villalobos, and Fernando Alvarez. "Larval development of the stygobitic shrimp Creaseria morleyi (Creaser, 1936) (Decapoda: Caridea: Palaemonidae) from the Yucatán Peninsula, Mexico." Journal of Crustacean Biology 40, no. 3 (February 20, 2020): 221–29. http://dx.doi.org/10.1093/jcbiol/ruaa006.

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Abstract Although the larval development of epigean palaemonid shrimps has been studied extensively, only a few investigations deal with stygobitic species. We present the larval development of the cave-adapted Creaseria morleyi (Creaser, 1936) from anchialine caves in the Tulum area, Quintana Roo, Yucatán Peninsula, Mexico. Through the discovery of a series of larvae at different stages of development, we constructed a sequence extending through the juvenile stage. The larvae (41) were captured in plankton tows above the halocline at depths ranging between 11 and 15 m during eight surveys conducted between 2013 and 2016. Six larval stages and the first juvenile were identified; however, it is clear from the gradual modification of structures and appendages that more stages exist. The first larvae have a large quantity of vitellum and do not feed, since they have only rudimentary, and possibly non-functional, mouthparts. In the sixth stage and the juvenile, when the stages have no vitellum left, the mouthparts, chelae, and pleopods develop entirely. A comparison with other palaemonid shrimps suggests that C. morleyi has a greater affinity with those palaemonid species possessing extended larval development as is seen in species of MacrobrachiumSpence Bate, 1868.

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Laberge, Robert J. A., and J. Daniel McLaughlin. "Hyalella azteca (Amphipoda) as an intermediate host of the nematode Streptocara crassicauda." Canadian Journal of Zoology 67, no. 9 (September 1, 1989): 2335–40. http://dx.doi.org/10.1139/z89-329.

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The life cycle of Streptocara crassicauda (Creplin, 1829) was studied experimentally in the amphipod Hyalella azteca (Saussure). Of 2946 H. azteca that survived exposure, 699 were infected. Developing larval stages were found almost exclusively in the cephalic haemocoel. At 18–20 °C, moulting first-stage larvae were observed initially on day 11 and moulting second-stage larvae on day 15 post infection. The moult was not synchronous and moulting stages were found for several days after the initial observation. Third-stage larvae were found as early as day 19 post infection. The larval stages found in H. azteca are described. Mature females containing larvated eggs were recovered from domestic ducks (Anas platyrhynchos dom.) 9–21 days post exposure, and eggs were found in fecal samples on day 26. None of the females recovered from ducks 42 days post infection contained larvated eggs.

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Pitts, James P., and Robert W. Matthews. "Description of the Larva of Sphaeropthalma pensylvanica (Lepeletier) (Hymenoptera: Mutillidae: Sphaeropthalminae)." Journal of Entomological Science 35, no. 3 (July 1, 2000): 334–37. http://dx.doi.org/10.18474/0749-8004-35.3.334.

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The larval stage of Sphaeropthalma pensylvanica (Lepeletier) is described and differentiated from other known larval Mutillidae. The larva of S. pensylvanica differs from the other described larvae of Mutillidae by the following combination of characters: the tenth abdominal segment rounded and not produced over the anus, a basal mandibular tooth half the size of the third mandibular tooth, large, densely clustered sensilla on the labrum, and prominent pleural lobes.

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Yan, Yan, Chen Haoru, Huang Liangmin, and Sun Lihua. "Larval development of the barnacle Ibla cumingi (Cirripedia: Pendunculata: Iblidae) reared in the laboratory." Journal of the Marine Biological Association of the United Kingdom 85, no. 4 (June 27, 2005): 903–7. http://dx.doi.org/10.1017/s0025315405011872.

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Larvae of Ibla cumingi from Daya Bay, China were cultured in the laboratory. Larval development includes six naupliar stages and a non-feeding cypris stage following the ground patterns of cirripeds. Larvae reached the cypris stage in nine days at ∼25°C after hatching. Morphological features including the cephalic shield, frontal horns, labrum, abdominal process, antennules, antennae and mandibles in all nauplii were described and illustrated using light microscopy. A full morphological description of cyprid larvae was provided using scanning electron microscopy. Attempts were made to compare the difference between the larval development model of I. cumingi and that of Ibla species.

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Nogata, Yasuyuki, and Kiyotaka Matsumura. "Larval development and settlement of a whale barnacle." Biology Letters 2, no. 1 (November 15, 2005): 92–93. http://dx.doi.org/10.1098/rsbl.2005.0409.

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Larval development and settlement of whale barnacles have not previously been described, unlike intertidal barnacles. Indeed, the mechanisms of the association between barnacles and whales have not been studied. Here we describe the larval development and settlement of the whale barnacle, Coronula diadema , and possible involvement of a cue from the host in inducing larval settlement. Eight-cell stage embryos were collected from C. diadema on a stranded humpback whale, incubated in filtered seawater for 7 days, and nauplius larvae hatched out. When fed with Chaetoceros gracilis , the nauplii developed to stage VI, and finally metamorphosed to the cypris stage. The larval development looked similar to that of intertidal barnacles with planktotrophic larval stages. The cyprids did not settle in normal seawater, but did settle in polystyrene Petri dishes when incubated in seawater with a small piece of skin tissue from the host whale. This strongly suggests the involvement of a chemical cue from the host whale tissue to induce larval settlement.

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León, Roxana, Leonardo R. Castro, and Mario Cáceres. "Dispersal of Munida gregaria (Decapoda: Galatheidae) larvae in Patagonian channels of southern Chile." ICES Journal of Marine Science 65, no. 7 (June 16, 2008): 1131–43. http://dx.doi.org/10.1093/icesjms/fsn093.

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Abstract León, R., Castro, L. R., and Cáceres, M. 2008. Dispersal of Munida gregaria (Decapoda: Galatheidae) larvae in Patagonian channels of southern Chile. – ICES Journal of Marine Science, 65: 1131–1143. The dispersal of Munida gregaria larvae in Chilean Patagonian channels was assessed in spring 2002 and 2003, and winter 2003. In winter 2003, zoea I was the most abundant stage in all channels and there were no larval stages older than zoea IV. In spring 2002 and 2003, there were six larval stages in all channels, and the greater abundance of older larvae suggested that reproduction takes place in winter and larval development in spring. Further, analysis of spatial distribution by stage revealed that early zoeae moved seawards. Generalized Additive Models analyses showed that most larval stages were temperature-dependent, and that the salinity range of the youngest zoea was wider than that of older larvae and post-larvae, coinciding with an ontogenetic distribution change from estuary to shelf. Residual flows determined with an acoustic Doppler current profiler revealed two layers of opposite flow: the shallowest layer moved seawards and the deeper layer onshore. The surface layer was wider in spring than in winter because of seasonal increase in fresh-water input. The dispersal pattern of M. gregaria consisted of an inner channel larval release in winter, followed by an along-channel larval drift and subsequent export to the shelf in spring. The mechanism by which juveniles return to the channels seemed to be associated with the onshore subsurface flow.

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Bradford, R. W., D. Griffin, and B. D. Bruce. "Estimating the duration of the pelagic phyllosoma phase of the southern rock lobster, Jasus edwardsii (Hutton)." Marine and Freshwater Research 66, no. 3 (2015): 213. http://dx.doi.org/10.1071/mf14065.

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The phyllosoma larva of the southern rock lobster, Jasus edwardsii, is thought to be among the longest larval phases of any planktonic larva, with estimates in the literature ranging from 12 to 24 months. In the present study, we have used an extensive archive of samples (over 2800 samples with 680 phyllosoma) to refine the estimate of the duration of the pelagic phase. The distribution through the year of larval stages suggested that larvae from two separate spawning events were present in any 12-month period. Using regression analysis, we have estimated the duration of the phyllosoma phase to be 547±47.5 days (~18.2±1.6 months). A new model of J. edwardsii phyllosoma development is presented and compared with data on known hatching and settlement patterns. The new model will improve the paramiterisation of stage-specific biophysical models of larval dispersal and regional connectivity, to better inform management of the southern rock lobster fisheries.

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Takahashi, Motomitsu, Hiroshi Nishida, Akihiko Yatsu, and Yoshiro Watanabe. "Year-class strength and growth rates after metamorphosis of Japanese sardine (Sardinops melanostictus) in the western North Pacific Ocean during 1996–2003." Canadian Journal of Fisheries and Aquatic Sciences 65, no. 7 (July 2008): 1425–34. http://dx.doi.org/10.1139/f08-063.

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Growth trajectories during larval to early juvenile stages in Japanese sardine ( Sardinops melanostictus ) were backcalculated based on the widths of otolith daily increments from 1996 to 2003 in the nursery grounds, Kuroshio–Oyashio transitional waters. Planktonic larvae hatched near Kuroshio have been transported northeastward from the Kuroshio waters to the transitional waters. We show that the somatic growth rates sharply increased after metamorphosis to the early juvenile stage, whereas previously, others showed that growth rate decreases during the larval stage. Otolith growth rates were more variable during the juvenile stage than the larval stage. Interannual variations in the otolith growth rate after metamorphosis explained more than 80% of variation in abundances of recruits (ca. 8–10 months old) in the Pacific coastal waters, whereas no correlation was found between the growth rate during the early larval stage and abundance. Our result was consistent with the hypothesis of growth rate-dependent recruitment success in the Kuroshio–Oyashio transitional waters.

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Heckford, R. J., and S. D. Beavan. "Coleophora arctostaphyli Meder, 1934 (Lepidoptera: Coleophoridae): observations on the early stages." Entomologist's Gazette 69, no. 2 (April 28, 2018): 115–18. http://dx.doi.org/10.31184/g00138894.692.1680.

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The ovum and larva of the case-bearing stage of Coleophora arctostaphyli Meder, 1934, are apparently undescribed, unlike the larva of the leaf-mining stage, larval case and biology. Descriptions of the ovum and final instar are provided but for reasons given in the text only a limited account is given of the final instar. We also record finding several mines on the foodplant, Arctostaphylos uva-ursi (L.) Spreng., containing dead larvae.

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Yee, Wee L. "Seasonal Distributions of Eggs and Larvae of Rhagoletis indifferens Curran (Diptera: Tephritidae) in Cherries." Journal of Entomological Science 40, no. 2 (April 1, 2005): 158–66. http://dx.doi.org/10.18474/0749-8004-40.2.158.

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The seasonal distributions of eggs and first-, second-, and third-instar larvae of the western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), in sweet cherries were determined at three sites in central Washington in 2002 and 2003. The egg was the major stage during early, mid and late season. The distributions of eggs (i.e., the percentages of total immature stages that were eggs) were similar all season, but those of first, second and third instars were greatest in late season. First, second and third instars occurred in similar numbers in 2002, but third instars were the most abundant in 2003. Tree quadrant had no effect on egg and larval densities and distributions. The majority of infested fruit had only one egg or larva, but there were significant increases in percentages of fruit with two or ≥ three eggs or larvae as percentages of fruit that were infested increased during the season. When there were two larvae in a fruit, one was larger than the other in 90.8% of cases. Results indicate time of season but not location within trees (1.5 to 2 m above ground) has differential effects on egg and larval distributions in fruit and on female oviposition behaviors that may result in multiple infestations and larval interactions. Seasonal effects on immature stages are probably related to developmental times and stage-specific mortality; whereas, effects on adults may be related to reduced availability of unoccupied fruit for oviposition.

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Duguid, William D. P., and Louise R. Page. "Larval and early post-larval morphology, growth, and behaviour of laboratory reared Lopholithodes foraminatus (brown box crab)." Journal of the Marine Biological Association of the United Kingdom 89, no. 8 (August 3, 2009): 1607–26. http://dx.doi.org/10.1017/s002531540900068x.

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The larval and post-larval behaviour, growth, colour, and morphology of the brown box crab (Lopholithodes foraminatus) are described for the first time based on laboratory reared animals. A detailed morphological description is provided for 4 zoeal stages, the glaucothoe, and the first crab instar. Selected morphological changes over the remainder of the first year of development are also described. Data are presented on larval growth at 11°C and on zoeal stage durations at approximately 8°C, 12°C and 16°C. While the 4 zoeal stages are planktotrophic, the glaucothoe does not feed; a life history character that has been termed ‘secondary lecithotrophy’. Growth of L. foraminatus larvae and post-larvae is generally similar to that of other North Pacific lithodids with planktotrophic zoeae. Zoeal stage durations decrease with increasing temperature. This relationship levels off at approximately 16°C, a higher temperature than in lithodid species from colder regions. Carapace morphology is suggested as a diagnostic character of larval and post-larval stages of Lopholithodes foraminatus. Secondary lecithotrophy may be widespread or even universal among lithodids and also occurs in pagurid hermit crabs. If the family Lithodidae is indeed nested within the Paguridae, as suggested by recent phylogenetic hypotheses based on molecular evidence, secondary lecithotrophy may be plesiomorphic in lithodids.

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Zinke, I., C. Kirchner, L. C. Chao, M. T. Tetzlaff, and M. J. Pankratz. "Suppression of food intake and growth by amino acids in Drosophila: the role of pumpless, a fat body expressed gene with homology to vertebrate glycine cleavage system." Development 126, no. 23 (December 1, 1999): 5275–84. http://dx.doi.org/10.1242/dev.126.23.5275.

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We have isolated a Drosophila mutant, named pumpless, which is defective in food intake and growth at the larval stage. pumpless larvae can initially feed normally upon hatching. However, during late first instar stage, they fail to pump the food from the pharynx into the esophagus and concurrently begin moving away from the food source. Although pumpless larvae do not feed, they do not show the typical physiologic response of starving animals, such as upregulating genes involved in gluconeogenesis or lipid breakdown. The pumpless gene is expressed specifically in the fat body and encodes a protein with homology to a vertebrate enzyme involved in glycine catabolism. Feeding wild-type larvae high levels of amino acids could phenocopy the feeding and growth defects of pumpless mutants. Our data suggest the existence of an amino acid-dependent signal arising from the fat body that induces cessation of feeding in the larva. This signaling system may also mediate growth transition from larval to the pupal stage during Drosophila development.

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Christo, SW, TM Absher, and G. Boehs. "Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae)." Brazilian Journal of Biology 70, no. 3 (August 2010): 645–50. http://dx.doi.org/10.1590/s1519-69842010000300023.

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In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

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Flyachinskaya, L. P., and P. A. Lezin. "Larval and juvenile development of the Iceland cockle Ciliatocardium ciliatum (Fabricius, 1780) (Bivalvia: Cardiidae)." Proceedings of the Zoological Institute RAS 324, no. 2 (June 25, 2020): 242–51. http://dx.doi.org/10.31610/trudyzin/2020.324.2.242.

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The paper considers the development of Ciliatocardium ciliatum from the stage of straight hinge to juvenile. In the White Sea the spawning of C. ciliatum begins at the end of June, larvae at different stages of development occur in plankton until the end of September. The earliest of the larvae found had shell lengths of 123–130 µm. The paper first examined the anatomy and structure of the larval shell of C. ciliatum. During the development, the main stages of organogenesis were described and special attention was paid to the formation of the digestive and muscular systems. The digestive system begins to function when the larva reaches a size of 170–180 µm. The digestive gland has a two-blade shape and is shifted to the right side. The foot is formed at a size of 230 µm, the gill rudiments appear when the larva reaches 270 µm. The development of the larval shell and larval hinge of the mollusc is considered in detail. The development of the larval shell of C. ciliatum is similar to the development of other family members. Throughout all the larval stages, the shell has a rounded shape with a low umbos, and the prodissoconch II has a clearly visible concentric structure. The C. ciliatum larval hinge is characterized by weak differentiation and the absence of pronounced cardinal teeth typical for other Cardiidae. However, the lateral structures of the castle – ridges and flanges – are well developed. The ligament begins to form at a size of 240–250 µm and occupies a lateral position. The settlement of the cockle takes place in September in the subtidal zone. After the metamorphosis, a large radial sculpture is formed on the dissoconch and a number of small spikes are formed at the rib of the posterior shoulder.

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Schjetlein, J., and A. Skorping. "The temperature threshold for development of Elaphostrongylus rangiferi in the intermediate host: an adaptation to winter survival?" Parasitology 111, no. 1 (July 1995): 103–10. http://dx.doi.org/10.1017/s0031182000064659.

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SUMMARYTo test the hypothesis that the relatively high developmental temperature threshold of the parasitic nematode Elaphostrongylus rangiferi in the intermediate snail host is an adaptation to minimize larval mortality during winter, an experiment was set up in which snails of the species Arianta arbustorum were experimentally infected with the parasite. The snails were divided into 3 groups known to contain 1st, 2nd or 3rd-stage larvae, and incubated at 3 °C for an experimental period of 18 weeks. First-stage larvae showed a significantly higher survival rate within snails than 2nd or 3rd-stage larvae. We also found that snails carrying 1st-stage larvae survived better than snails with other larval stages. It is concluded that if the nematode has started development before the hibernation, this has a real and significant effect on the risk of dying. The high developmental threshold is therefore likely to be an adaptation to reduce the chance of hibernating as developing larvae during long periods of low temperatures.

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Marco-Herrero, Elena, Klaus Anger, and Liliam Hayd. "Extended larval development in the hololimnetic shrimp Macrobrachium pantanalense (Decapoda, Palaemonidae) reared in the laboratory." Crustaceana 92, no. 6 (May 31, 2019): 693–723. http://dx.doi.org/10.1163/15685403-00003899.

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Abstract The postembryonic development of Macrobrachium pantanalense, a freshwater shrimp from central South America, was experimentally studied in the laboratory. In contrast to most other hololimnetic Caridea, this species passes through an extended larval phase with intraspecific variability in the number and morphology of stages. Here we describe the shortest developmental pathway comprising nine zoeal stages, the first post-zoeal stage (morphologically transitional between a late larva and an early juvenile), and an early juvenile with vestiges of larval traits. Post-zoeal development is characterized by a gradual reduction of the natatory exopods of the pereiopods (a larval character) and a concurrent transformation of the endopods to walking legs (juvenile trait). A comparison with the larvae of a closely related, often confused estuarine species from northern South America, M. amazonicum, revealed consistent interspecific differences, especially in the morphology of the fifth pereiopod, allowing for an unambiguous distinction of these two allopatric congeners.

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MONTEZANO, DÉBORA G., ALEXANDRE SPECHT, TARCISO M. BORTOLIN, EDEGAR FRONZA, DANIEL R. SOSA-GÓMEZ, VÂNIA F. ROQUE-SPECHT, PATRÍCIA PEZZI, PRISCILA C. LUZ, and NEIVA M. BARROS. "Immature stages of Spodoptera albula (Walker) (Lepidoptera: Noctuidae): Developmental parameters and host plants." Anais da Academia Brasileira de Ciências 85, no. 1 (March 2013): 271–84. http://dx.doi.org/10.1590/s0001-37652013000100013.

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This study aimed to detail the temporal and morphological parameters of the immature stages of Spodoptera albula (Walker 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase) and to gather information about their larval host plants. For this purpose, a new rearing method and artificial diet was employed and validated. The viability of the egg, larval, pupal and pre-pupal stages was 94.54, 97.33, 93.84 and 92.34%, respectively. The average duration of the egg, larval, pupal and pre-pupal stages was 4.14, 16.37, 1.69, and 9.34 days, respectively. During the larval stage, 80.85% of females and 93.99% of males passed through six and remaining through seven instars, with significant larval protandry. The larvae that developed through six and seven instars exhibited a mean growth rate of 1.58 and 1.48, respectively. Fifty five host plant species belonging to 29 families are listed. The female pupae were significantly larger, exhibiting protogyny. Both the rearing methods as well as the larval diet proved adequate, providing more detailled observations of the biological cycle, especially the larval stage, and resulting in an overall survival of almost 80%.

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Abrunhosa, Fernando A., Darlan J. B. Simith, Carlos A. M. Palmeira, and Danielle C. B. Arruda. "Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae)." Anais da Academia Brasileira de Ciências 80, no. 4 (December 2008): 639–46. http://dx.doi.org/10.1590/s0001-37652008000400005.

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Food supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development). In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period. High survival rate was observed in both experiments, in which only 2 megalopae and 1 zoea III died. These results strongly suggest that larvae of L. siriboia are lecithotrophic as they have sufficiently large yolk reserve to complete their larval development, while the megalopa stage shows facultative lecithotrophy. The larval periods of each stage of the treatments were quite similar and, despite some significant differences in some larval periods, these can be related probably to larval rearing conditions, abiotic factors or, individual variability of larval health, as well as stress caused to the ovigerous females during embryogenesis.

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Soluk, Daniel A., and Hugh F. Clifford. "Microhabitat shifts and substrate selection by the psammophilous predator Pseudiron centralis McDunnough (Ephemeroptera: Heptageniidae)." Canadian Journal of Zoology 63, no. 7 (July 1, 1985): 1539–43. http://dx.doi.org/10.1139/z85-228.

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The predaceous mayfly Pseudiron centralis McDunnough exhibited shifts in its association with different types of sandy substrate during larval development: stage I larvae were associated with marginal sands; stage II larvae exhibited no association; and stage III and IV larvae were associated with the substrate of the main-stream channel of the river, where sand is formed into active dunes (shifting sand). Ability to occupy areas of shifting sand is size related, probably because small larvae cannot cope with the physical stresses of these areas. Experiments indicate that stage III larvae avoid gravel, but do not differentiate between sand and silt. Shifting sands are hypothesized to be favourable environments for larger larvae because of greater accessibility of chironomid prey or the absence of potential predators in these areas. Larval spacing behavior is unlikely to affect patterns of larval distribution or density on the riverbed.

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Watai, Mikio, Taiki Ishihara, Osamu Abe, Seiji Ohshimo, and Carlos Augusto Strussmann. "Evaluation of growth-dependent survival during early stages of Pacific bluefin tuna using otolith microstructure analysis." Marine and Freshwater Research 68, no. 11 (2017): 2008. http://dx.doi.org/10.1071/mf16337.

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The present study used otolith analysis-based body size back-calculation to: (1) evaluate the hypothesis of growth-dependent survival in young Pacific bluefin tuna (PBF; Thunnus orientalis) from the north-western Pacific Ocean; (2) identify critical developmental stages for survival; and (3) compare interannual differences in early growth. To this end, we compared the daily growth trajectories of a large number of larvae (standard length (SL) <15mm), juveniles (15≤SL≤150mm), and young-of-year (YOY; SL >150mm) collected between 2011 and 2015. Otolith radius and SL were highly correlated and yielded a single relationship applicable for the five year-classes. Body size back-calculation showed that only larvae with fast, steady growth successfully transitioned to the juvenile stage. The ontogenetic analysis of daily growth rates revealed interannual differences only in larvae, and not in the larval stage of juveniles and YOY. Neither sudden decreases nor increases in growth rates were observed during the larval stage of any of the stages, suggesting that the observed variability in larval body size may be the result of individual differences in growth rates rather than of drastic, one-time events. Overall, the results of the present study indicate that growth-dependent survival of larvae may be the most critical for PBF recruitment.

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Journal articles on the topic 'Larval stage'

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