Thesis (Ph. D.)--University of Washington. / Bibliography: l. 186-196.

Inaug.-diss. - Berlin. / Vita. "Libri adhibiti": p. 33-34.

Within life-history trait variations for two herbivorous intertidal lacunids, Lacuna pallidula, a direct developer and Lacuna vincta a planktotroph, were compared and related to their ecology and to marine invertebrate life-history theory. Aspects of life-history theory covered included; reproductive investment, the relationship between egg size and egg fecundity, the Egg-Juvenile-Period (EJP), the implications of egg size for offspring status and maternal effects. Similar patterns of growth and reproductive investment were observed for adult females of both species, although absolute rates of growth and reproduction were differently affected by macroalgal diet. Further, differences in response to the favourability of macroalgal diet were observed for the two species, notably in the manner in which eggs were packaged. Variations in both egg size and egg numbers in spawn masses were observed for the two species, among populations within both species and within Lacuna pallidula populations. For Lacuna pallidula, these variations were shown to be mediated by both maternal macroalgal diet and population source. Maternal diet directly affected the size of hatching offspring but not the size of eggs produced. Consequently, egg size was not a good indicator of hatching size for either species. The EJP was determined for both species for a range of temperatures. Greater variations in the EJP and juvenile size were observed in Lacuna vincta. This was attributed to the ability of the larvae of this species to delay metamorphosis and to display positive growth during the delay phase. Both temperature and microalgal diet were shown to affect patterns of growth and development in Lacuna vincta larvae. Sources of naturally occurring cues for inducing settlement and metamorphosis in Lacuna vincta larvae were investigated to understand further the distribution patterns of this species on macroalgal types. Extension of the work investigated the suitability of various artificial cues for inducing metamorphosis and the effects of larval age and nutritional status of larvae upon latency of response to established inducing cues. Overall, L. pallidula displayed greater variation in traits and was more sensitive to environmental change than L. vincta. This finding is discussed in light of the two species larval strategy.

This study concerns the reproductive and larval ecology of the nudibranch Adalaria proxima. Attainment of competence is demonstrated to be cue specific. Embryos metamorphose in response to choline, yet remain precompetent to elevated potassium and the natural cue until after hatching. It is hypothesized that the choline-mediated metamorphic pathway (or choline-sensitive portion of the natural pathway) becomes functionally complete ontogenetically earlier than do larval chemoreceptors. Larvae metamorphose in response to sea water 'conditioned' (CSW) by the bryozoan Electra pilosa. A range of littoral organisms failed to induce metamorphosis and it is suggested that A. proxima displays a high degree of cue specificy. It is reported that CSW-mediated metamorphosis is dose dependent and effected in a disparate manner to that of potassium. No evidence for a bacterial role in metamorphosis was found. These results are intended to facilitate future isolation of the natural cue. Both starved (lecithotrophic) and fed (facultatively planktotrophic) larvae may successfully delay metamorphosis for 28-31d post-hatching (at 10-C). Larval fitness appeared to be unaffected by nutritional status, which is suggested to reflect the transitional evolutionary nature of facultative planktotrophy. The lowered fitness commensurate with an extended pelagic period is hypothesized to confer a lowered dispersal potential. A. proximais semelparous, producing up to eleven spawn before dying. Significant variation in reproductive traits is demonstrated within and between six U.K. populations of A. proxima Intrapopulation decreases in egg size, fecundity and hatching success with spawn laying sequence are suggested to reflect phylogenetic constraints. Interpopulation differences in egg size and fecundity are considered consistent with the predicted limited larval dispersal potential. Population egg size was correlated to larval size but not latitude or fecundity. Possible causative factors of the observed interpopulation variation in reproductive traits are discussed, and most probable causes hypothesized.

No description available.

Thesis (Ph. D.)--University of Washington, 1995. / Vita. Includes bibliographical references (leaves [249]-286).

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-26T15:00:04Z No. of bitstreams: 1 Dissertação - Timoteo Tadashi Watanabe.pdf: 811295 bytes, checksum: 167d496a5bd123f48ac7690e0fa8bb6b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-28T12:42:11Z (GMT) No. of bitstreams: 1 Dissertação - Timoteo Tadashi Watanabe.pdf: 811295 bytes, checksum: 167d496a5bd123f48ac7690e0fa8bb6b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-28T12:42:23Z (GMT) No. of bitstreams: 1 Dissertação - Timoteo Tadashi Watanabe.pdf: 811295 bytes, checksum: 167d496a5bd123f48ac7690e0fa8bb6b (MD5) / Made available in DSpace on 2016-01-28T12:42:23Z (GMT). No. of bitstreams: 1 Dissertação - Timoteo Tadashi Watanabe.pdf: 811295 bytes, checksum: 167d496a5bd123f48ac7690e0fa8bb6b (MD5) Previous issue date: 2014-02-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Gastropods from the Ampullariidae family are divided among nine genera being the most famous the Pomacea genera. There is about 20 species of Pomacea that lives in the Amazon ecosystem which has influence of flood pulses of the rivers. So this study evaluated the daily activity and the influence of the flood pulse in the apple snails behavior using Pomacea bridgesii as a model and also evaluated the desiccation resistance of the apple snails comparing the resistance between Pomacea amazonica and P. bridgesii. The gastropods were sampled between May 2012 and June 2013 in the city of Itacoatiara, Amazonas, Brazil. The daily activity, substratum selection and flood pulse simulation were made under natural light and temperature. The behaviors were registered on an ethogram and the daily activity was observed for 48 hours and the flood pulse simulation observations were made during 70 days. In the desiccation resistance experiment, the animals were put in plastics recipients and weighted with 24 hours interval until the death of the animals, after that the animals were dried on a 60ºC kiln to obtain the dry weight. Pomacea bridgesii had more activity during the night where up to 80% of the animals were exploring the tank and during the day up to 80% were immobile. The most used substratum was the pebble. When comparing day with night the part of the usage of pebble during the day shifted to the smooth surface significantly (X²=26.51; DF=3; P<0.05). The behavior of P. bridgesii related to the simulated flood pulse had significant difference between flood peak and dry period but there was no significant difference between the rising water period and the draining period. As for the desiccation resistance, P. amazonica survived a maximum of 314 days and P. bridgesii 157. There was neither difference between the sexes of both species nor difference between species. The size comparison was different for P. amazonica which the small individuals (5--|30 mm) survived less than the medium sized ones (30--|55 mm; H=13.33; DF=2; Z=2.78; P<0.05) and large ones (≥55 mm; H=13.33; DF=2; Z=3.11; P<0.05), and for P. bridgesii the large animals (≥36 mm) survived more time than small individuals (12--|25 mm; H=14.40; DF=2; Z=3.42; P<0.05) and medium ones (25--|36 mm; H=14.40; GL=2; Z=2.90; P<0.05). The species showed similar survival tendency and water loss although the maximum survival time was different. So we can conclude that P. bridgesii displays more activity during the night and had more usage of the pebble substratum during the day, but part of this usage shifted to the smooth surface relating to their nocturnal activity. This species also displayed adaptations to the complex Amazon ecosystem interrupting the activities and closing their operculum to survive the long drought period. And both Pomacea amazonica and P. bridgesii have high desiccation resistance as a part of their adaptations for the ecosystem which allows them to survive the drought period of the Amazon basin and even longer drought periods which may happen. / Os moluscos Ampullariidae estão divididos em nove gêneros sendo Pomacea o mais conhecido mundialmente. Cerca de 20 espécies do gênero Pomacea vivem no ecossistema amazônico sob a influência de um regime de pulsos de inundações. Tendo isso em vista, este estudo avaliou o comportamento diário e a influência do regime de água amazônico no comportamento de Pomacea bridgesii REEVE, 1856 como modelo. Adicionalmente, avaliou-se a resistência à dessecação por Pomacea amazonica REEVE, 1856 e P. bridgesii, para testar a hipótese de que os gastrópodes resistem à seca sazonal que ocorre na região. Os gastrópodes foram coletados entre maio de 2012 e junho de 2013 no Município de Itacoatiara, Amazonas, Brasil. A avaliação da atividade diária, seleção de substrato e simulação do pulso de inundação foram realizadas sob condições de luz e temperatura ambiente. Os comportamentos foram registrados em um etograma elaborado em experimentos preliminares. A atividade diária foi observada por 48 horas e as observações da simulação do pulso de inundação foram feitas em um período de 70 dias. No experimento de resistência à dessecação, os animais foram colocados em recipientes plásticos e pesados a cada 24 horas até a morte do animal; em seguida foram secos em estufa a 60ºC para a obtenção do peso seco. Os animais apresentaram mais atividade durante a noite quando até 80% dos indivíduos estavam explorando o ambiente e até 80% permaneciam imóveis durante o dia. Tanto para o dia como para a noite os gastrópodes utilizaram principalmente o substrato composto por seixo. Comparando a seleção entre o dia e a noite, parte dos animais que utilizavam o seixo durante o dia passou a usar substrato liso significantemente (X²=26,51; GL=3; P<0,05). O comportamento de P. bridgesii em relação à simulação do pulso de inundação mostrou diferença significativa entre a cheia e a seca e não houve diferença significativa entre os períodos da enchente e vazante. Quanto à resistência à dessecação, P. amazonica sobreviveu um tempo máximo de 314 dias e P. bridgesii 157. Não houve diferença da sobrevivência entre os sexos de ambas as espécies e nem quando comparado o tempo entre as espécies. A comparação entre tamanhos foi significativo para P. amazonica em que os indivíduos menores (5--|30 mm) apresentaram uma taxa de sobrevivência menor do que os indivíduos médios (30--|55 mm; H=13,33; GL=2; Z=2,78; P<0,05) e grandes (≥55 mm; H=13,33; GL=2; Z=3,11; P<0,05), e P. bridgesii, em que os indivíduos maiores (≥36 mm) apresentaram uma taxa de sobrevivência maior do que os indivíduos pequenos (12--|25 mm; H=14,40; GL=2; Z=3,42; P<0,05) e médios (25--|36 mm; H=14,40; GL=2; Z=2,90; P<0,05). As espécies apresentaram tendência de sobrevivência e de perda de água semelhantes apesar da diferença de tempo máximo de sobrevivência. Desse modo, pode-se concluir que P. bridgesii possui maior atividade durante a noite, teve maior uso do substrato composto por seixo durante o dia, mas durante a noite parte desse uso passou para o substrato liso relacionado a sua atividade noturna. Também mostrou adaptações ao complexo ecossistema amazônico, interrompendo as atividades e fechando seu opérculo para sobreviver aos longos períodos de seca que ocorrem na região amazônica. E tanto P. amazonica como P. bridgesii possuem elevada resistência à dessecação como parte de sua forma de adaptação suportando todo o período de seca e até mesmo secas de longa duração, evidenciando estarem adaptadas ao ambiente da várzea amazônica.

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