Influence of temperature on larval survival, development and respiration in Chasmagnathus granulata (Crustacea, Decapoda)

Larvae of an estuarine grapsid crab Chasmagnathus granulata Dana 1851, from temperate and subtropical regions of South America, were reared in seawater (32 ‰) at five different constant temperatures (12, 15, 18, 21, 24 °C). Complete larval development from hatching (Zoea I) to metamorphosis (Crab I) occurred in a range from 15 to 24 °C. Highest survival (60% to the first juvenile stage) was observed at 18°C, while all larvae reared at 12°C died before metamorphosis. The duration of development (D) decreased with increasing temperature (T). This relationship is described for all larval stages as a power function (linear regressions after logarithmic transformation of both D and T). The temperature-dependence of the instantaneous developmental rate (D-1) is compared among larval stages and temperatures using the Q10 coefficient (van't Hoff's equation). Through all four zoeal stages, this index tends to increase during development and to decrease with increasing T (comparing ranges 12-18, 15-21, 18-24 °C). In the Megalopa, low Q10 values were found in the range from 15 to 24 °C. In another series of experiments, larvae were reared at constant 18°C and their dry weight (W) and respiratory response to changes in T were measured in all successive stages during the intermoult period (stage C) of the moulting cycle. Both individual and weight-specific respiration (R, QO2) increased exponentially with increasing T. At each temperature, R increased significantly during growth and development through successive larval stages. No significantly different QO2 values were found in the first three zoeal stages, while a significant decrease with increasing W occurred in the Zoea IV and Megalopa. As in the temperature-dependence of D, the respiratory response to changes in temperature (Q10) depends on both the temperature range and the developmental stage, however, with different patterns. In the zoeal stages, the respiratory Q10 was minimum (1.7-2.2) at low temperatures (12-18 °C), but maximum (2.2-3.0) at 18-24 °C. The Megalopa, in contrast, showed a stronger metabolic response in the lower than in the upper temperature range (Q10 = 2.8 and 1.7, respectively). We interpret this pattern as an adaptation to a sequence of temperature conditions that should typically be encountered by C. granulata larvae during their ontogenetic migrations: hatching in and subsequent export from shallow estuarine lagoons, zoeal development in coastal marine waters, which are on average cooler, return in the Megalopa stage to warm lagoons. We thus propose that high metabolic sensitivity to changes in temperature may serve as a signal stimulating larval migration, so that the zoeae should tend to leave warm estuaries and lagoons, whereas the Megalopa should avoid remaining in the cooler marine waters and initiate its migration towards shallow coastal lagoons.

Effects of nitrate concentration on larval development of the giant river prawn, Macrobrachium rosenbergii

The effect of nitrate concentration on giant river prawn, Macrobrachium rosenbergii, larvae was investigated. Survival rate, weight gain, and larval development were evaluated for different concentrations of nitrate in three experiments. The experiments were divided i n to two phases. In the first phase, larvae from stages I through VIII were analysed, while in the second phase larvae from stage VIII through post-larvae metamorphosis were analysed. Oxygen consumption was also determined for zoea I, II, and VIII exposed to 0, 700, and 1,000 mg/L of nitrate-N. No effect was observed for concentrations up to 180 mg/L NO3-N (experiments I and II), and nitrate levels as 1,000 mg/L NO3-N did not affect survival in the first phase of the third experiment. On the other hand, larval stage index (LSI) and weight gain decreased as nitrate-N concentration increased from 0 to 1,000 mg/L. In the second phase, survival and metamorphosis rate decreased as nitrate concentration increased, according to a linear model. The effect of nitrate levels on weight gain followed a curvilinear pattern. Larval respiration decreased in the water where nitrate was added, but only during stage II. The results demonstrated that nitrate presents extremely low toxicity for giant river prawn larvae, and data were related to the levels of nitrate that usually occur in larviculture systems also discussed. Therefore, nitrate is not a limiting factor for giant river prawn larviculture. © 2003 by The Haworth Press, Inc. All rights reserved.

Desenvolvimento embrionário do camarão-da-amazônia Macrobrachium amazonicum (Heller, 1862) (Crustacea, Decapoda, Palaemonidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribuição espacial dos decapoditos e caranguejos juvenis num estuário tropical

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Níveis de cálcio, fósforo, lipídeo e proteína na dieta inerte do camarão-da-malásia Macrobrachium rosenbergii, na fase larval

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First zoeal stage of ? Cataleptodius parvulus (Fabricius, 1793) and Xanthodius denticulatus (White, 1848) (Decapoda: Brachyura): larval evidences and systematic position

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First zoeal stage of the partner shrimp Periclimenes paivai Chace, with remarks on the genus Periclimenes OG Costa (Caridea, Palaemonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morfologia e distribuição dos estágios larvais de representantes da família Porcellanidae Haworth (Crustacea: Decapoda: Anomura) obtidas no nêuston da região de Ubatuba, SP

O presente projeto visa um estudo morfológico de formas planctônicas iniciais de crustáceos decápodos da família Porcellanidae. Os representantes da família Porcellanidae são bons indicadores da diversidade e complexidade das estruturas litorais, quando em relações simbióticas. E possuem também grande importância na cadeia trófica, sendo a base alimentar de muitos peixes de interesse econômico. Seu desenvolvimento larval conta com um estágio pré-zoea, dois estágios zoea e um estágio glaucothoe. O estágio de pré-zoea tem curta duração, comumente de 5 minutos a 5 horas, sendo coberto por uma cutícula embrionária. Os estágios de zoea são facilmente reconhecidos pelos grandes espinhos rostral e posterior da carapaça. O estágio de glaucothoe apresenta todos os somitos e apêndices presentes no caranguejo adulto, com redução somente no número de pleópodos. Para o estudo foram utilizadas as amostras da coleção do NEBECC (Núcleo de Estudo de Biologia, Ecologia e Cultivo de Crustáceos) feitas para o projeto “Morfologia dos estágios iniciais do desenvolvimento de Crustáceos Decápodos Pleocyemata, do litoral norte paulista” aprovado pela FAPESP (proc. 04/15194-6). Estas amostras foram triadas em estereomicroscópio e, separadas as larvas por região (inshore e offshore) e estágios larvais. Os estágios de larvais foram desenhados e análisados com ênfase nos maxilipedes secundário e terciário e no télson. Os resultados foram analisados estatisticamente por métodos não-paramétricos, apresentando uma homogeneidade na distribuição dos estágios larvais tanto inshore quanto offshore

Morphology of the first larval stage of Macrobrachium brasiliense (Heller, 1868) (Caridea: Palaemonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of salinity on the metabolism and osmoregulation of selected ontogenetic stages of an Amazon population of Macrobrachium amazonicum shrimp (Decapoda, Palaemonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)