The reproductive biology of Kidderia (Kidderia) subquadratum (Pelseneer, 1903) was studied from collections which were made at Palmer Station, Antarctica during 1970 and 1971. Kidderia subquadratum is a small lamellibranch (the largest observed was 6.8 mm long) found on rocky substrates in the intertidal and subtidal zones of the Antarctic Peninsula. The sexes are separate and the females comprised 54.1% of the population studied. The differential in the sex ratio is neither size nor age related. The females are ovoviviparous and retain their embryos in brood pouches of the demibranchs. The brood pouch is a modification of the form and function of the ancestral, molluscan ctenidia and allows the retention of embryos by the female. The eggs are large and rich in yolk. Embryogenesis is without traces of the typical marine, molluscan larvae, the trochophore and the veliger. Development of the embryo follows the normal indirect, marine lamellibranch pattern until gastrulation. This includes unequal cleavage, formation of a stereoblastula with a reduced blastocoel, and gastrulation by epiboly with slight invagination. Following gastrulation development is considerably modified and follows the normal freshwater lamellibranch pattern of direct development. This is partially attributed to the large amounts of yolk that the egg contains, to the absence of the free living trochophore and veliger larvae, and to the incidence of brood protection. No structures analogous to the trochophore and veliger larvae occur. The reproductive system is described and includes the male and female systems, and the ctenidial and siphonal systems. The female gonad is unusual in that unilaminar ovarian follicles are present. The follicles consist of simple squamous follicle epithelia and either developing oögonia or oöcytes. Oögenesis takes 15 to 19 months. Egg formation consists of the rounding-off of a single germ cell which includes a nucleolus, nucleus, and cytoplasm complex. This complex, called an oögonium, grows out from the germinal epithelium into the lumen of the ovocyst. The solitary egg formation of K. subquadratum is modified and includes a unilaminar follicle epithelium which surrounds the growing oögonium. The follicle epithelium does not appear to serve any nutritional role in egg growth. Oögonia are sloughed-off during the year and lost from the population. There is no consistent seasonal variation in the numbers of oögonia observed in the ovaries. Primary oöcytes are present in females of the population from December until July. Individual females spawn continuously for a minimum of five months. Spermiogenesis and spawning in the male precedes the development of primary oöcytes by one month. Males spawn only once or at discrete periods with periodic build-ups of spermatozoa. Spermatozoa are shed directly into the water. Fertilization takes place in the brood pouches, epibranchial chambers, or oviducts, or all three areas, of the adult female after the eggs are released from the ovary. Spermatozoa are drawn through the inhalant siphon of the female, into the mantle cavity. Entrance to the brood pouches is afforded by the gill ostia, openings between the gill filaments. The eggs may be fertilized as primary oöcytes during the germinal vesicle stage of maturation, or after the breakdown of the germinal vesicle, or during both stages. The follicular epithelium, which is persistent throughout development, may bind the embryos together and thus prevent their premature loss from the brood pouches. The brood size is dependent on the size of the female. The larger females contain the greater numbers of embryos. From one to 250 embryos were observed in individual females during the study. The brood potential, per female of the population, is 96 ± 63 individuals. There is almost a 90% loss of the initial brood potential during development. Development of the embryo can take place, at least for short periods, outside the maternal organism. The period of development of the embryos is five months. The juveniles have a mean size of 0.503 mm at liberation which occurs during the austral winter and spring. The byssus system of the embryo is active at liberation thus allowing immediate attachment to a substrate. The gill at liberation is a simple, paired structure consisting of the descending lamellae of the inner demibranchs. Sexual differentiation of the juvenile gonad occurs within approximately four months of liberation at a mean size of 0.916 mm. Gametogenesis begins in the females prior to a length of 1.333 mm or approximately at an age of nine months. Sexual maturity in the juveniles occurs between 2.00 and 2.66 mm and represents an age of approximately 18 to 22 months. There is no upper size or age limit of fertility in the males or females of the population. Active feeding in the juveniles begins two months after release from the maternal organism. The major food of K. subquadratum, a filter feeding bivalve, consists of diatoms, algal fragments, dinoflagellates, and organic detritus. The winter and spring periods of liberation are attributed to the synchronizing effect of the spring phytoplankton blooms which are light limited. Light is considered to be the primary controlling factor on reproduction of Kidderia subquadratum. Direct development is thought to have arisen in the Kidderia subquadratum population as a result of the loss of the trochophore and veliger larval stages of development which was brought about by the evolution of maternal brood protection in the population. Direct development is probably maintained in the population by the combined pressures of yolk-rich eggs, ovoviviparity, a five month period of development of the embryos, and a winter-spring liberation of the juveniles. / Graduation date: 1975

Bibliography: pages 287-318. / This thesis examines the physiology and energetics of D. serra and considers physiological responses to elevated temperature and chlorine levels typical of sea water discharged from a nuclear power station.

published_or_final_version / Zoology / Master / Master of Philosophy

Proefschrift Rijksuniversiteit Groningen. / Franse titel: Tree of the sea : het gebruik van interne groeilijnen in de schelp van "Arctica islandica" met het oog op het retrospectief inschatten van veranderingen in het mariene milieu. Datum laatste controle: 04-06-1997. Lit.opg. - Met een samenvatting in het Nederlands.

This study has shown that season, salinity, temperature and intertidal height all affect the rate up calcium uptake by mussels. For summer-adapted mussels, calcium uptake was found to be temperature dependent over the range of acute temperatures measured (1°-23°C). When subjected to a range of salinities over a three week period, summer-adapted mussels showed calcium-uptake rates which were salinity dependent from 25%-75% SW, and which did not show any increase in uptake rate in salinities greater than 75% SW. For winter-adapted mussels, calcium uptake was temperature independent over a temperature range from 5°-l7°C. At higher and lower temperatures, uptake was reduced. When subjected to a range of salinities over a three-week period, winter-adapted mussels were also unable to compensate for the lower concentration of calcium in the seawater, and did not show any increase in the uptake rate in salinities greater than 75% SW. It was found that high and low intertidal mussels had different calcium uptake rates, and that transplantation could alter the uptake rate of transplanted mussels to the uptake rate of untransplanted controls. In the intertidal zone a gradient of shell size was found, which could be associated with the change in uptake range over the intertidal range. Differences in immersion time between the two. sites could not explain all of the differences in uptake rate, but high intertidal mussels were found to have less total dry weight of soft parts than low mussels, and correcting for this difference accounted for the the remainder of the difference in calcium-uptake rate between the two sites. The soft parts of the mussel were found to become saturated with ⁴⁵Ca after four hours, while the shell accumulated calcium for the duration of the experiment. The mantle and gill tissue held the same amount of calcium when corrected for differences in weight, while the viscera held a greater pool of calcium. Accounting for real increases in the amount of calcium accumulated by the shell showed that the uptake rates reported in this study are about 59% of the absolute uptake rates. / Science, Faculty of / Zoology, Department of / Graduate

Os principais objetivos deste trabalho são: 1) estudar o material malacofaunístico de novos jazigos da região de Rio Claro - Piracicaba (SP) e de testemunhos de sondagem de Conchas (SP), referentes à porção basal da Formação Corumbataí, termo superior do Grupo Passa Dois de idade permiana e 2) determinar sua distribuição bioestratigráfica. Incluiu-se um exame parcial da provável correlação entre as faunas das bases das Formações Corumbataí (São Paulo) e Estrada Nova (Paraná) e considerações de ordem paleoecológica da malacofauna. A análise taxonômica dos bivalves da porção basal da Formação Corumbataí no Estado, forneceu apreciável diversidade genérica e específica. Duas secções colunares, uma de superfície e outra de subsuperfície são apresentadas, mostrando a distribuição bioestratigráfica dessa malacofauna. Os bivalves identificados e descritos nos diversos afloramentos foram: Angatubia cf. A. cowperesioides Mendes, Anthraconaia ? mezzalirai sp. n., Barbosaia cf. B. angulata Mendes, Barbosaia roxoi sp n., Casterella cf. C. camargoi Beurlen, Ferrazia simplicicarinata Mezzalira, Ferrazia sp., Holdhausiella elongata Mendes, Holdhausiella sp., Kidodia cf. K. stockleyi Cox, Mendesia piracicabensis gen. et sp. n., Plesiocyprinella sp., Rioclaroa cf. R. lefrevei Mezzalira. Com base na composição observada, sugeriu-se reunir as Zonas Leinzia froezi Mendes e Barbosaia angulata Mendes propostas por MEZZALIRA (1980) em uma única designada Zona Leinzia froezi - Barbosaia angulata. Os quatro níveis fossilíferos reconhecidos em subsuperfície (Poço 1-IG-Conchas) com as espécies: Casterella cf. C. gratiosa, Ferrazia cardinalis Reed e Pinzonella cf. P. illusa, a julgar pela distribuição vertical em relação à base da formação, situar-se-iam na Zona III de MEZZALIRA (1980) considerada quando definida como afossilífera. Dentre as principais conclusões, notou-se a predominância de bivalves com carenas simples e a duplas, provavelmente caráter adaptativo ao ambiente que seria provavelmente circunscrito, mixo-halino, de águas rasas, turvas e mal oxigenadas em certos intervalos. / The main purpose of this dissertation is: 1) to study malacofaunistic material concerning new occurrences in the Rio Claro-Piracicaba (SP) region and concerning drilling core in Conchas (SP), refering the basal portion from Corumbataí Formation, upper section of the Passa Dois Group of Permian age and 2) to determine its biostratigraphical distribution. It is included a partial examination about the probable correlation between fauna belonging to Corumbataí Formation (SP) bases and Estrada Nova (Paraná) and considerations on malacofauna paleoecological order. The taxonomic analysis of the basal portion bivalves from Corumbataí Formation in the State of SP, furnished remarkable specific and generic diversity. Two columnar section, one from surface and the other from subsurface are presented showing the malacofauna biostratigraphic distribution. The bivalves identified and described in the various outcrops were : Angatubia cf. A. cowperesioides Mendes, Anthraconaia ? mezzalirai sp. n., Barbosaia cf. B. angulata Mendes, Barbosaia roxoi sp. n., Casterella cf. C. canargoi Beurlen, Ferrazia simplicicarinata Mezzalira, Ferrazia sp., Holdhausiella elongata Mendes, Holdhausiella sp., Kidodia cf. K. stockleyi Cox, Mendesia piracicabensis gen. et sp. n., Plesiocyprinella sp., Rioclaroa cf. R. lefevrei Mezzalira. With basis in the observed composition, it was suggested to congregate the Zonas Leinzia froesi Mendes and Barbosaia angulata Mendes proposed by MEZZALIRA (1980) in one unique named: Zona Leinzia froesi - Barbosaia angulata. The four fossiliferous levels acknowledged in the subsurface with the specimens: Casterella cf. C. gratiosa, Ferrazia cardinalis Reed and Pinzonella cf. P. illusa verifying by the vertical distribution related with the formation basis, it would be locate in Zona III from MEZZALIRA (1980) considered when defined as afossiliferous. Among the main conclusions were observed the prevalence of bivalves with simple and two carina, probably an adaptation to the environment, which would be classified as: mixo-halino, of shallow waters, darkish and with bad oxygenated in certain intervals.

Os principais objetivos deste trabalho são: 1) estudar o material malacofaunístico de novos jazigos da região de Rio Claro - Piracicaba (SP) e de testemunhos de sondagem de Conchas (SP), referentes à porção basal da Formação Corumbataí, termo superior do Grupo Passa Dois de idade permiana e 2) determinar sua distribuição bioestratigráfica. Incluiu-se um exame parcial da provável correlação entre as faunas das bases das Formações Corumbataí (São Paulo) e Estrada Nova (Paraná) e considerações de ordem paleoecológica da malacofauna. A análise taxonômica dos bivalves da porção basal da Formação Corumbataí no Estado, forneceu apreciável diversidade genérica e específica. Duas secções colunares, uma de superfície e outra de subsuperfície são apresentadas, mostrando a distribuição bioestratigráfica dessa malacofauna. Os bivalves identificados e descritos nos diversos afloramentos foram: Angatubia cf. A. cowperesioides Mendes, Anthraconaia ? mezzalirai sp. n., Barbosaia cf. B. angulata Mendes, Barbosaia roxoi sp n., Casterella cf. C. camargoi Beurlen, Ferrazia simplicicarinata Mezzalira, Ferrazia sp., Holdhausiella elongata Mendes, Holdhausiella sp., Kidodia cf. K. stockleyi Cox, Mendesia piracicabensis gen. et sp. n., Plesiocyprinella sp., Rioclaroa cf. R. lefrevei Mezzalira. Com base na composição observada, sugeriu-se reunir as Zonas Leinzia froezi Mendes e Barbosaia angulata Mendes propostas por MEZZALIRA (1980) em uma única designada Zona Leinzia froezi - Barbosaia angulata. Os quatro níveis fossilíferos reconhecidos em subsuperfície (Poço 1-IG-Conchas) com as espécies: Casterella cf. C. gratiosa, Ferrazia cardinalis Reed e Pinzonella cf. P. illusa, a julgar pela distribuição vertical em relação à base da formação, situar-se-iam na Zona III de MEZZALIRA (1980) considerada quando definida como afossilífera. Dentre as principais conclusões, notou-se a predominância de bivalves com carenas simples e a duplas, provavelmente caráter adaptativo ao ambiente que seria provavelmente circunscrito, mixo-halino, de águas rasas, turvas e mal oxigenadas em certos intervalos. / The main purpose of this dissertation is: 1) to study malacofaunistic material concerning new occurrences in the Rio Claro-Piracicaba (SP) region and concerning drilling core in Conchas (SP), refering the basal portion from Corumbataí Formation, upper section of the Passa Dois Group of Permian age and 2) to determine its biostratigraphical distribution. It is included a partial examination about the probable correlation between fauna belonging to Corumbataí Formation (SP) bases and Estrada Nova (Paraná) and considerations on malacofauna paleoecological order. The taxonomic analysis of the basal portion bivalves from Corumbataí Formation in the State of SP, furnished remarkable specific and generic diversity. Two columnar section, one from surface and the other from subsurface are presented showing the malacofauna biostratigraphic distribution. The bivalves identified and described in the various outcrops were : Angatubia cf. A. cowperesioides Mendes, Anthraconaia ? mezzalirai sp. n., Barbosaia cf. B. angulata Mendes, Barbosaia roxoi sp. n., Casterella cf. C. canargoi Beurlen, Ferrazia simplicicarinata Mezzalira, Ferrazia sp., Holdhausiella elongata Mendes, Holdhausiella sp., Kidodia cf. K. stockleyi Cox, Mendesia piracicabensis gen. et sp. n., Plesiocyprinella sp., Rioclaroa cf. R. lefevrei Mezzalira. With basis in the observed composition, it was suggested to congregate the Zonas Leinzia froesi Mendes and Barbosaia angulata Mendes proposed by MEZZALIRA (1980) in one unique named: Zona Leinzia froesi - Barbosaia angulata. The four fossiliferous levels acknowledged in the subsurface with the specimens: Casterella cf. C. gratiosa, Ferrazia cardinalis Reed and Pinzonella cf. P. illusa verifying by the vertical distribution related with the formation basis, it would be locate in Zona III from MEZZALIRA (1980) considered when defined as afossiliferous. Among the main conclusions were observed the prevalence of bivalves with simple and two carina, probably an adaptation to the environment, which would be classified as: mixo-halino, of shallow waters, darkish and with bad oxygenated in certain intervals.

Made available in DSpace on 2014-06-12T23:01:47Z (GMT). No. of bitstreams: 2 arquivo8325_1.pdf: 1354296 bytes, checksum: b5d7d888cde32dcdbd8a85ab53c82798 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / No estuário do Rio Formoso que está localizado no Estado de Pernambuco (8o39´45´´ latitude sul e 35o09´15´´ longitude oeste), foram feitas coletas no período de janeiro de 1999 a dezembro de 2000, em quatro estações fixas durante as baixa-mares ao longo do manguezal, visando avaliar a distribuição dos bivalves endofaunais e correlacionar com alguns parâmetros abióticos (temperatura ambiental, salinidade da água intersticial e granulometria de sedimento). Os dados climatológicos foram cedidos pelo Instituto de Meteorologia (INMET). Amostras de água intersticial do manguezal e sedimento foram coletadas em cada estação e levadas ao Laboratório de Química da Empresa Pernambucana Agropecuária, para a análise. Paralelamente, em cada estação foram coletadas amostras de sedimento, utilizando-se um delimitador de alumínio com 50 cm de lado, lavadas em água no próprio local de coleta e passadas por peneiras de 2,0 a 1,0 mm de abertura de malha com intuito de separar representantes de moluscos da endofauna. Posteriormente os moluscos foram triados e levados ao laboratório da Universidade Católica de Pernambuco para a identificação taxonômica. Foram levantados dados sócio-econômicos aplicando-se questionários de entrevista com a comunidade pesqueira para traçar perfil dos pescadores da região. A temperatura ambiental mensal variou entre 25,7 o C, no mês de fevereiro a 23 o C, no mês de agosto/1999. No ano 2000 a temperatura variou de 24 o C nos meses de julho e agosto a 26,5 o C em janeiro, fevereiro e dezembro A precipitação pluviométrica no ano de 1999 variou de 5,0 mm, nos meses de fevereiro e novembro a 310mm, no mês de maio. No ano de 2000 a precipitação variou de 640 mm, no mês de julho a 9 mm, no mês de novembro. Os valores de salinidade da água intersticial, no ano de 1999, variaram de 2,0 , no mês de janeiro a 30,0 , nos mês de outubro; no ano de 2000, variou de 2,3 , no mês de julho a 27,5 , no mês de novembro. Os valores de temperatura da água intersticial, no ano de 1999, variaram de 24 oC, no mês de maio a 35oC, no mês de novembro; no ano de 2000, variou de 22oC, no mês de maio a 29oC, no mês de dezembro.Através das análises de variações granulométricas do sedimento, constatou-se que, houve predominância da fração areia grossa em todas as estações estudadas, embora em algumas estações, tenha havido um aumento nos teores de silte, indicando uma oscilação na classe textual de arenoso para siltoso. As espécies da endomalacofauna bivalvia que apresentaram maior abundância foram Tagelus plebeius, Mytella falcata, Lucina pectinata, nas estações estudadas no ano de 1999; enquanto que no ano 2000 sobressaiu nesse sentido, a espécie Lucina pectinata. Espécie de maior freqüência no ano de 1999 foi Tagelus plebeius e no ano de 2000, a Lucina pectinata. As densidades (Ind./10m2) dos moluscos bivalvia da endofauna no manguezal do rio Formoso, variaram de 3.420 Ind./10m2,no mês de maio a 9.500 Ind./10m2,no mês de novembro para o ano de 1999 e, no ano 2000, variaram de 4.370 Ind./10m2, no mês de julho a 10.350 Ind./10m2, no mês de novembro. A comunidade pesqueira vive da pesca artesanal rudimentar, em função de suas condições sócioeconômicas, cuja renda familiar é menor que um salário mínimo. O manguezal de rio Formoso vem passando por intensa ação antrópica, devido a uma sucessão de fatores impactantes (desmatamento,aterros,lixo,esgoto doméstico,industrial e hospitalar),o que poderá ser causa de redução, no futuro, de moluscos da endofauna

Genetic variation at twelve loci which code for enzymes and non-enzymatic protein has been studied by means of starch gel electrophoresis in two apparent species of the pelecypod genus Transennella, Variable allozymes include esterase, leucine aminopeptidase, malate dehydrogenase, phosphoglucose isomerase, tetrazolium oxidase, and nonenzymatic protein, Observed allele frequencies for these systems are in close agreement with Hardy-Weinberg expectations indicating that these protandric hermaphrodites are outbreeding. The genus is characterized by two distinct morphotypes which differ in shell shape and pigmentation. Genetic similarity (I) and genetic distance (D) statistics were computed for the two morphotypes and for two populations of each morphotype. The I and D values derived from intraspecific comparisons of Transennella tantilla populations are 0.99 and 0,004; for Transennella sp., the I value is also 0.99 and D is 0,002. The I and D values obtained from interspecific comparisons (T. tantilla versus T, sp.) are 0,521 and 0,650 respectively. An extensive survey of the phosphoglucose isomerase system was conducted to evaluate microgeographic variation and age-dependent frequency selection at this locus. Differences in allele frequencies were found to be non-significant, suggesting that this locus is without selective import, or that selection for a particular genotype is too slight to be detected with the sample sizes employed, The amount of genetic divergence found between the morphotypes is comparable to interspecific estimates made for a variety of invertebrate species. The results indicate that the morphological divergence apparent in the two morphotypes has been accompanied by substantial genetic differentiation.

As global climate change accelerates, there is increasing concern about how ecosystems may change as a result of biodiversity loss and species replacement. Marine bivalves are important as commercial food resources, ecosystem-engineers and invasive or fouling species. Understanding how beneficial and harmful bivalve species may respond to the changing environment will be important for marine coastal management. Given the expected speed of climate change, it is unlikely that species will have time to evolve adaptively in time, instead, they will have to tolerate environmental stressors or acclimate and vary their life history traits. Studies were conducted to compare the interspecific differences in thermal tolerance between the non-invasive bivalve Septifer virgatus and the invasive Perna viridis, to see if differential tolerance can explain the invasion success of bioinvaders. The intraspecific thermal tolerance of the invasive P. viridis was also assessed to determine how thermal tolerance may differ among populations. In the second stage of the study, by acclimating both S. virgatus and P. viridis at different temperatures, the interspecific differences in thermal acclimation capacity was tested to assess their susceptibility to climate change. As the two species are ecologically and economically important, understanding how they will respond to climate change is important to help manage fisheries and coastal resources. Results showed that S. virgatus had a higher thermal tolerance than P. viridis in the cold and dry season in Hong Kong, but after acclimation at 27°C, which is the average sea surface temperature in the hot and wet season in Hong Kong, P. viridis had significantly increased its thermal tolerance and was more tolerant than S. virgatus acclimated at the same temperature, showing this species has a high capacity for acclimation. In comparison, S. virgatus showed limited acclimation capacity. The results suggest that to conclusively determine the full potential of a species' thermal tolerance, tests have to be conducted in different seasons to take into account phenotypic plasticity. The broad thermal tolerance range and the highly flexible physiology of P. viridis may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world. As invasive species are generally more stress tolerant and plastic, it is expected that global climate change will facilitate bioinvasion, and efforts to manage this will need to take into account the physiological capacities of these species. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management