Larval development of Notolopas brasiliensis Miers, 1886 (Brachyura: Majoidea: Pisidae) described from laboratory reared material and a reappraisal of the characters of Pisidae

O completo desenvolvimento larval de Notolopas brasiliensis é descrito, a partir de material criado em laboratório, com ênfase na morfologia externa de Majoidea e comparado aos demais gêneros de Pisidae. O desenvolvimento larval de N. brasiliensis consiste em dois estágios de zoea e um de megalopa. A duração media de cada estágio foi de 4.2 ± 1.0 dias para a Zoea I e 3.8 ± 0.7 dias para a Zoea II, a megalopa aparece entre 8.1 ± 0.4 dias após a eclosão. Os caracteres previamente utilizados para definir as formas larvais de Pisidae ou são simplesiomórficos ou altamente homoplásticos. Foi observado que não existe um conjunto de caracteres capazes de definir Pisidae até o presente.Contudo foi mostrado que uma combinação de caracteres pode ser utilizada para diferenciar Notolopas dos demais gêneros da família.

Kinetic Analysis of Gill (Na+,K+)-ATPase Activity in Selected Ontogenetic Stages of the Amazon River Shrimp, (Decapoda, Palaemonidae): Interactions at ATP- and Cation-Binding Sites

We investigated modulation by ATP, Mg2+, Na+, K+ and NH4 (+) and inhibition by ouabain of (Na+,K+)-ATPase activity in microsomal homogenates of whole zoeae I and decapodid III (formerly zoea IX) and whole-body and gill homogenates of juvenile and adult Amazon River shrimps, . (Na+,K+)-ATPase-specific activity was increased twofold in decapodid III compared to zoea I, juveniles and adults, suggesting an important role in this ontogenetic stage. The apparent affinity for ATP ( (M) = 0.09 +/- A 0.01 mmol L-1) of the decapodid III (Na+,K+)-ATPase, about twofold greater than the other stages, further highlights this relevance. Modulation of (Na+,K+)-ATPase activity by K+ also revealed a threefold greater affinity for K+ ( (0.5) = 0.91 +/- A 0.04 mmol L-1) in decapodid III than in other stages; NH4 (+) had no modulatory effect. The affinity for Na+ ( (0.5) = 13.2 +/- A 0.6 mmol L-1) of zoea I (Na+,K+)-ATPase was fourfold less than other stages. Modulation by Na+, Mg2+ and NH4 (+) obeyed cooperative kinetics, while K+ modulation exhibited Michaelis-Menten behavior. Rates of maximal Mg2+ stimulation of ouabain-insensitive ATPase activity differed in each ontogenetic stage, suggesting that Mg2+-stimulated ATPases other than (Na+,K+)-ATPase are present. Ouabain inhibition suggests that, among the various ATPase activities present in the different stages, Na+-ATPase may be involved in the ontogeny of osmoregulation in larval The NH4 (+)-stimulated, ouabain-insensitive ATPase activity seen in zoea I and decapodid III may reflect a stage-specific means of ammonia excretion since functional gills are absent in the early larval stages.