Dissertations / Theses on the topic 'Barnacle larvae'

In the past half century, a number of studies have described the general composition of the mesozooplankton of Southampton Water, highlighting aspects about the seasonality of the major components and identifying calanoid copepods and barnacle larvae as the major elements. Despite the number of studies, almost all knowledge about species composition, dominance and succession patterns of the mesozooplankton as a whole, is described from only a few studies, usually located at stations in the mid and lower estuary. It is clear that generalizations made for these stations will not reflect other parts of this estuary. Because of this, a 120 μm net-haul study comprising upper, mid and lower stations within Southampton Water was conducted over a period of 19 months, from 12/01/01 until 16/07/02, in order to critically re-evaluate the mesozooplankton community of the estuary, as well as to assess the importance of copepods and barnacle larvae to pelagic carbon fluxes. Additional biological and non-biological water column parameters were measured concurrently. A total of 144 different taxa were recorded within the zooplankton of Southampton Water during this study, with 92 identified to species, 30 to genus and 22 identified at a higher level. From these 31 were identified as holoplankton, 72 as meroplankton and 41 as tycoplankton, with 90 taxa recorded for the first time in Southampton Water. Numerically the zooplankton community was mainly composed of holoplankton forms (~69%), followed by meroplankton (~30%) and tycoplankton (~1%). Copepod nauplii were the most abundant holoplanktonic taxa, averaging 38% of all forms, followed by the calanoid Acartia spp. (31%), the cyclopoid Oithona nana (11%), the harpacticoid Euterpina acutifrons (11%) and the appendicularia Oikopleura sp. (5%). Barnacle larvae averaged 53% of the meroplanktonic forms, followed by polychaete (19%), gastropod (13%), bivalve (9%) and bryozoan larvae (3%). Harpacticoid copepods comprised 97% of the tycoplanktonic forms recorded. One unexpected finding of this study was the significant occurrence of the cyclopoid Oithona nana within the upper estuary, contrasting with previous studies where calanoids of the genus Acartia were considered the only dominant copepod form. Although present throughout the estuary, O.nana was clearly most abundant in the upper estuary where it presented a clear seasonal pattern, and was numerically the most abundant form from late-summer until early-winter, then replaced by copepod nauplii and Acartia spp. during mid-winter to late-spring, and by copepod nauplii, Acartia spp. and E.acutifrons during early to mid-summer. Barnacle larvae presented the same composition and seasonality reported in the past, with Elminius modestus the most abundant and frequent, and occurring throughout the year although it was outnumbered by Balanus crenatus from February to May. Of the remaining barnacle species found only Balanus improvisus, Semibalanus balanoides and Verruca stroemia were present in substantial numbers. Production of several copepod components was calculated, and an overall averaged production of 253.48 mg C m-3 yr-1 was estimated, with Acartia accounting for 55.6% of the production followed by E.acutifrons (16.0%), copepod nauplii (15.2%) and O.nana (13.2%). This previously unaccounted production may assist in readdressing the relatively low copepod secondary production previously estimated for Southampton Water. Production of barnacle larvae was also calculated and an overall averaged production of 32.80 mg C m-3 yr-1 was estimated, with E.modestus alone accounting for 54.7% followed by B.crenatus (35%), B.improvisus (6.7%), S.balanoides (3.1%) and V.stroemia (0.5%). Overall, production of barnacle larvae within Southampton Water is significantly lower than that of calanoid copepods contradicting previous assumptions that barnacle larvae could provide as much secondary production as calanoids. A new set of simple linear regression equations applicable to a range of crustacean zooplankton types are proposed for the preliminary estimation of production based primarily on the total number of organisms. Abundance, in conjunction with temperature, salinity and chlorophyll a pattern were also employed in the elaboration of multiple regression equations. Production values calculated by this new method were usually ±20% of the averaged value obtained by more conventional methods. When applied to an independent data set, differences of only ±7% were observed between production estimates using conventional and the new equations. The new estimated production values for barnacle larvae (meroplankton), Acartia (calanoid), Oithona (cyclopoid), Euterpina (harpacticoid) and copepod nauplii components of the mesozooplankton are integrated into an existing carbon-flux box-model for Southampton Water.

ix, 84 leaves : ill. ; 29 cm Notes Typescript Thesis (M.S.)--University of Oregon, 2003 Includes vita and abstract Includes bibliographical references (leaves 73-84) Another copy on microfilm is located in Archives

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2005.<br>Includes bibliographical references.<br>The geographic distribution and dynamics of coastal benthic populations are shaped by physical - biological interactions affecting larval dispersal and the demography of juvenile and adult individuals. This thesis focused on nearshore patterns of larval distribution and regional patterns in demography of intertidal barnacles in Southern and Baja California. Horizontal and vertical distributions, and the mortality rates of larvae, were assessed from short term (i.e. days) small- scale observations (0.1-1 km) in nearshore waters. Observations on spatial variability of adult barnacle demography were gathered over 1.5 years at scales of hundreds of kilometers. Stage-specific horizontal distributions and nearshore current measurements suggested that larvae of Balanus g-landula and Chthamalus spp. may experience limited dispersal. High mortality rates could further limit travel distances and the exchange of individuals among disjunct populations. Data on vertical distributions indicated that nauplii and cyprids of Balanus nubilus and Pollicipes polymerus occur at different depths. Nauplii remained near the surface at all times, whereas cyprids occurred in the bottom half of the water column.<br>(cont.) Such distributions, combined with vertical variability in horizontal flows, might cause the observed horizontal segregation of nauplii and cyprids. Differences in survival, growth rate, size structure, and per capita fertility of adult Balanus glandula were observed between Dana Point (Southern California) and Punta Baja (Baja California), a site located near the species' southern limit of distribution. Effects of spatial differences in demography on population persistence were assessed with a stage-structured matrix model. Model analyses indicated that the Punta Baja population is more susceptible to environmental stochasticity and more prone to local extinction than populations located further north. This thesis emphasizes the importance of characterizing factors that affect the dynamics of benthic populations at multiple spatial-temporal scales, and the usefulness of small scale high- frequency observations of nearshore phenomena, especially in relation with the dispersal of larvae.<br>by Fabián J. Tapia.<br>Ph.D.

O percebe (Pollicipes pollicipes) é o recurso económico mais importante da zona intertidal da costa rochosa Portuguesa. A abundância de larvas cypris (ultimo estado larvar) de percebe na Marina do Porto de Sines foi positivamente relacionada com a abundância de cypris e com o recrutamento de percebes no Cabo de Sines. O recrutamento de percebes foi mais intenso em 2012 do que em 2011 e 2013 (verão e outono) e esta variação não parece estar relacionada com a temperatura da água do mar. Foi estudada a variabilidade entre habitats (de cima e de baixo) e inter-anual (primavera de 2012, 2013 e 2014) da biomassa e densidade (total e de juvenis, e respectiva estrutura dimensional), tendo sido observado: uma maior biomassa e densidade no habitat de cima do que no de baixo em 2012, mas o mesmo não foi observado em 2013 e 2014; uma maior biomassa e densidade de forma geral no habitat de baixo em 2013 do que em 2012 e 2014 (primavera) que poderá estar relacionado com a maior intensidade do recrutamento no verão e outono de 2012 (padrão não evidente no habitat de cima). A taxa de crescimento de P. pollicipes diminuiu com o aumento do RC (distância entre as placas Rostrum e Carina). O crescimento médio mensal de percebe variou entre 0.3mm e 0.9mm (RC); Abstract: “Larval availability, recruitment, size structure and growth of the gooseneck barnacle (Pollicipes pollicipes) at Cape of Sines” The stalked barnacle Pollicipes pollicipes is the most important economical resource in portuguese rocky shores. Cyprid (last larval stage) abundance in the Marina of Sines was positively related with the cyprid abundance and the recruitment of P. pollicipes in the Cape of Sines. Recruitment was higher in 2012 than in 2011 and 2013 (summer/autumn). This pattern was not related with the inter-annual variability of seawater temperature. Habitat (low and high shore) and inter-annual (spring of 2012, 2013 and 2014) variability of biomass and density (total, of juveniles, and respective size structure) showed: a higher biomass and density in the high shore in 2012, but not in 2013 and 2014; a higher density and biomass in general in the low shore in 2013 than in 2012 and 2014 that might be related to the higher recruitment observed in 2012 (pattern not evident in the high shore). Growth rate of P. pollicipes diminished with size (RC, rostral-carinal distance) Mean monthly growth varied between 0.3mm e 0.9mm (RC).

碩士<br>國立中山大學<br>海洋生物科技暨資源學系研究所<br>104<br>Biofouling is a serious global issue of our oceans. Marine fouling organisms can attach on immersed artifical surfaces thus thus cause economic loss. This study utilized the major fouling barnacle species Amphibalanus amphitrite to test anti-fouling activities of more than one hundred natural compounds, including crude extracts, pure compounds and the derivatives isolated from marine organisms. There are more than one hundred natural compounds isolated from marine organisms and the derivatives were screened. There are three steps in our experiments: (1) Preliminary test: we prepared all natural compounds and the derivatives at the concertation of 10 ppm or 20 ppm and recorded the settlement condition of barnacle cypris larvae for 48 hours. (2) Antifouling activity test: we tested antifouling activities of potential compounds from step 1 at concentrations from 1-100 ppm. Then we estimated half maximal effective concentration (EC50), half lethal concentration (LC50) and therapeutic ratio (TR) of each compound. (3) Field test: we mixed the candidate compound with marine paint, then observed actual effect of the antifouling paint in the field. Our results showed that the pure compound S28 has high antifouling activity. The EC50 of S28 is 8.824 ppm, LC50 is 101.080 ppm and the therapeutic ratio (TR) is 11.454. These results suggested S28 is effective and has low toxicity. In conclusion, S28 has great potential for future development of antifouling paint.

碩士<br>國立中央大學<br>化學工程與材料工程學系<br>107<br>In the past few decades, elastic modulus, surface free energy and zwitterionic materials have been a key element of the development of marine antifouling coatings. This study combines a low elastic modulus material (polydimethylsiloxane, PDMS) and a zwitterionic material (sulfobetaine silane, SBSi) as a new anti-marine biofouling. Barnacle cypris larva (Amphibalanus amphitrite) and Ulva zoospores (Ulva lactuca, Ulva fasciata) are used as research species against marine biofouling. This study mainly carried out video tracking observation of cyprids (barnacle cypris larva), cyprids settlement assay and Ulva zoospores settlement assay, which used glass, fluorosilane, PDMS and SBSi. In the video tracking, the film showed that it had no tendency to adhere or could not adhere to the surface of PDMS-SBSI. At the same time, only 2% of the cyprids settled on the surface of the PDMS-SBSI for two days. In the settlement assay of Ulva zoospores, the attached number of zoospores is lower on the surface of PDMS-SBSI and the 92% of the attached zoospores removed after water flow impact. The study result indicate that the combination of PDMS and SBSI does have anti-contamination against barnacle cypris larva and Ulva zoospores, also, this combination exhibits superior fouling release characteristics when against Ulva zoospores. Based on these measurements, we will further investigate the stain release of PDMS-SBSI on barnacle cypris larva, or in-depth study of surface chemistry, using surface plasma resonator (SPR) to detect adhesion-induced protein complex (SIPC) adsorption on PDMS-SBSI.

碩士<br>國立臺灣大學<br>生態學與演化生物學研究所<br>107<br>Microplastics are plastic debris smaller than 5 mm in diameter. It has been shown that microplastics would cause many adverse impacts on zooplanktons such as reduce feeding rate, delay development and decrease fecundity. However, most studies evaluate the effect of microplastics focus on holoplankton, but relatively less studies focus on meroplankton. In the present study, we used the barnacle Amphibalanus amphitrite as a model organism for meroplankton to investigate the effects of four different sizes of polystyrene microplastics (diameter 1.7, 6.8, 10.4, 19.0 µm respectively) at four concentrations (1, 10, 100, 1000 beads mL-1). We found that stage II nauplii of A. amphitrite were able to ingest all four sizes of microplastics and efficiently egested them within several hours. Larval mortality, development time, growth rate, settling rate and metamorphosis percentage of microplastic treatments were not significantly different from that of control after being exposed to four different sizes of microplastics at any concentration from nauplii to cyprids. Moreover, feeding rate of nauplii (stage II- stage VI) were barely impaired at the concentration of 1000 beads mL-1. Overall, our results suggest that polystyrene microplastics have very limited impacts on the entire larval cycle of barnacle A. amphitrite. The microplastic exposed larvae could still successfully metamorphose to juvenile stage. We further extended the microplastic exposure over barnacle generations, continuously fed barnacle adults with same size of microplastic until they reproduced next generation offspring. Our results found that microplastics did not significantly affect adults of first generation but significantly increase larval mortality of next generation offspring, suggesting that microplastics have transgenerational effects. We also compared the larval mortality and retention time of microplastics between barnacle larvae from different habitats and climatic zones (Fistulobalanus albicostatus, Tetraclita japonica formosana, Chelonibia testudinaria, Neoacasta sp., Euacasta dofleini, Darwiniella angularis, Chthamalus dalli, Balanus glandula). We found that all barnacle species did not suffer increase mortality upon exposure to microplastics, but the retention time of microplastics significantly differed between barnacles lived in different habitats. Rocky shore and coral reef associated species have about 3-4 times longer microplastic retention time than the muddy shore species, suggesting that rocky shore and coral reef associated species might be more vulnerable to microplastic pollution.

碩士<br>國立臺灣大學<br>生態學與演化生物學研究所<br>104<br>Life cycle of barnacles is divided into two phases, with planktonic larval stage and adult sessile stage. Larval morphology and duration of larval development can affect the geographical distribution of barnacles. Examination of larval morphology and duration of larval development are important for further understanding of the larval ecology of intertidal species. The present study applied scanning electron microscope and optical microscopy techniques to examine the larval morphology of intertidal thoracican barnacles Tetraclita kuroshioensis, Tetraclita japonica formosana, Tetraclitella karandei, and the Acrothoracican barnacles Berndtia purpurea and B. utinomii. In the west Pacific, T. kuroshioensis has a wider range of distribution than T. japonica formosana which only present in Taiwan and Japan. Planktonic larval stage is the key period for dispersal with ocean current, which can affect the geographical distribution of species. In addition variations in tolerance to environmental stress, such as temperature and salinity between two species can result in different distribution pattern. Therefore, we compared the survival of larvae of T. kuroshioensis and T. japonica formosana at different temperatures (20, 25 and 30°C) and salinity (20, 25, 30 and 35 ‰). At 20°C, both larvae cannot metamorphosis to cyprids in all salinity treatment. At 25 and 30°C, naupliar duration is not significant different between two species. Therefore, variation in naupliar developmental duration between the two species did not affect their variation in geographical distribution. There are, however, greater percentage of stage VI larvae in T. kuroshioensis than T. japonica formosana at 25 and 30°C in all salinity situation. In addition, the number of metamorphosed cyprids is higher in T. kuroshioensis in most culture conditions. T. kuroshioensis has both high survival and metamorphosis rate, suggest they can survive in more strict condition, thus implying T. kuroshioensis has wider geographical distribution. This study provides 1) extensive database on larval morphology of Tetraclitidae barnacles of the West Pacific 2) first larval study of Acrothoraicican barnacles and 3) use larval ecology aspects to examine the factors affecting the geographical distribution of Tetraclita species in the west Pacific waters.

碩士<br>國立中山大學<br>海洋生物科技暨資源學系研究所<br>107<br>Larval development of many shallow water barnacle species (Crustacea: Cirripedia) has been well studied. In the deep sea, the larval development of some goose barnacles (Order Pedunculata) was briefly described but remained unknown for acorn barnacles (Order Sessilia). In addition, the presence of phototactic behaviors, which are common in larvae of shallow water species, remained controversial in the deep sea where light is limited. Striatobalanus tenuis (Hoek, 1883) is a deep sea (300 - 400m) acorn barnacle found in East and South China Sea. It inhabits on rocks, gastropod shells and crab surface and is commonly found as a bycatch of bottom trawl in Taiwan. In this study, we collected adult S. tenuis individuals from Kezailiao fishing port and cultivated their fertilized egg masses at 20°C. The hatched larvae were fed with microalgae and water is changed once a week. Precipitation of microalgae, which may disturb larval movement, was frequently removed. Six stages (NI-NVI) of swimming nauplius larvae and one stage of non-swimming cyprid larvae were successfully observed. Different nauplius stages of S. tenuis show morphological features corresponding to "normal" developmental sequence of barnacles. Red, green, blue and white light were applied to test phototaxis of S. tenuis nauplii. NII and NIII larvae were attracted by all the light settings. NIV and NV larvae showed positive phototaxis to all the light settings except blue light, which was negative. NVI larvae were repelled by all the light settings. The change of light preference at different nauplius stages might relate to their sequence of vertical migration. We suggested that the relaeased larvae migrate to shallower water, about 100m deep, to feed phytoplankton, then migrate back to the deep water for settlement.

碩士<br>國立臺灣大學<br>生態學與演化生物學研究所<br>98<br>Life cycle of intertidal organisms often consist a planktonic larval stage and followed by a sessile adult stage. Supply side ecology highlighted the relationship between larval supply, settlement and post-settlement mortality and their subsequent effect on the distribution and abundance of adults. The present study investigated larval supply using a newly designed plankton trap, which can efficiently sample larvae and quantify their supply patterns. The present study also focused on the early life history pattern of the abundant mid-shore barnacle Tetraclita kuroshioensis, to study the subsequent events of larval supply, settlement and post-settlement mortality on the population structure of adults at the NE Coast, Taiwan. The new designed trap in the present study can collect plankton during the splash and submerged period of the tidal cycle and yielded high diversity of catches, in which the sampling time is longer than the previously designed traps. Multivariate analysis showed that catch composition collected by the traps and the catches collected from hand-held plankton trawl net was similar, suggesting this trap was not selective. Using the new trap, the present study assessed the spatial and temporal variation in the supply of barnacle, bivalve and gastropod larvae in the NE Coast, Taiwan. Supply pattern of these larvae was affected by daily tidal range and wind speed. Diversity of larval supply of Taiwan intertidal barnacles was further investigated using this trap in ~12-month period (October, 2008 – October, 2009) at two sites (Shen Ao Kang and He Ping Dao) in the NE Coast. Morphological characters and molecular markers (CO1) are combined to identify barnacle cypris larvae. In morphological methods, carapace length, width and posterior carapace angle and antennules morphology was used to identify species. The result showed that morphological method can not identify barnacle cypris larvae to species level correctly. However, using the mitochondria CO1 molecular markers, we can identify barnacle species and proved that molecular method is more reliable to identify small-size barnacle cypris larvae in larval supply studies. The present study revealed the supply pattern of 19 common local barnacles which showed both spatial and temporal variations between these two sites. We also collected larvae of non-native barnacle species. Larval supply of the intertidal barnacle T. kuroshioensis had several supply pulses during the reproductive seasons. There were several small pulses in early summer but no settlement was followed. In summer, there was a single pulse, followed by sparse settlement and most of the settler can enter the populations as recruits (> 1 month old). Results suggesting the larvae and settlement density of Tetraclita sp. were not very high in Taiwan, as compared to the previous reported pattern in Hong Kong. Such variations can be attributed by difference in oceanographic current and climates between Taiwan and Hong Kong in the NW Pacific waters.