Multi-gene phylogeny of the primary freshwater crab genus Ptychophallus Smalley, 1964 (Pseudothelphusidae: Ptychophallinae) from the Neotropical region.

The diversity of primary freshwater crabs of Central America is underestimated and poorly known, specially when considering both Atlantic and Pacific drainages distribution. Among the family Pseudothelphusidae Ortmann, 1893, the genus Ptychophallus Smalley, 1964 was recently revised using morphological data and encompassing 14 valid species, which are distributed exclusively in Costa Rica and Panama. Despite the informative scenario constructed with this previous study, some uncertainties remained such as those related to the populations distributed along different drainages and the lack of complete information regarding the phylogenetic relationships among the species that belong to this genus.

The Influence of Natural Barriers on the Amphidromous Shrimp (Caridea, Atyidae) from Two Rivers in Southeastern Brazil.

AbstractThe migratory behavior of freshwater shrimps may be affected by natural barriers in limnetic environments. This study evaluated the river areas separated by natural barriers, such as waterfalls, which affect the amphidromous shrimps' () population features and reproductive aspects. Results indicate that in the Félix and Prumirim Rivers from southeastern Brazil shrimps show few differences in sampling areas, and these differences may not be causally related to the waterfalls.

Multigene phylogeny and taxonomic revision of American shrimps of the genus Dana, 1852 (Decapoda, Palaemonidae) implies a proposal for reversal of precedence with Spence Bate, 1868.

The freshwater shrimp genus Dana, 1852 has a disjunct distribution in North (Mexico) and South (Brazil, Chile) America, and is composed of only six species. The current classification of genera in the Palaemonidae is controversial, based on variable morphological characters, and still far from a clear definition. differs from the speciose genus Spence Bate, 1868 only by the absence of the hepatic spines on the carapace.

The influence of environmental variables in the reproductive performance of Macrobrachium amazonicum (Heller, 1862) (Caridea: Palaemonidae) females in a continental population.

Macrobrachium amazonicum is a commercially important freshwater prawn with a high degree of reproductive plasticity. The species is classified into two groups: coastal populations, with larger individuals exhibiting high fecundity and needing brackish water for larval development; and continental populations, with smaller specimens exhibiting low fecundities and completing metamorphosis in freshwater. The objective of this study was to investigate the influence of environmental factors in the fecundity, egg size and volume, and reproductive output in females of M.

The first zoeal stage morphology of Achelous spinimanus (Latreille), A. gibbesii (Stimpson), and Portunus sayi (Gibbes) (Decapoda, Brachyura) provides support for molecular phylogeny.

Taxonomic rearrangements were recently proposed for some members of Portunus Weber and Cronius Stimpson, including the re-elevation of the status of the subgenus Achelous De Haan to accommodate 21 American species. In the present study the first zoea of Achelous spinimanus, type species of the genus, A. gibbesii and Portunus sayi were obtained from laboratory-hatched specimens.

Morphological description of early zoeal stages of Alpheus brasileiro Anker, 2012 reared in the laboratory, including a revision of the larval morphology of the first zoeal stage of the genus Alpheus Fabricius, 1798 (Caridea: Alpheidae).

The aims of this study were to describe and illustrate the early larval stages of the snapping shrimp Alpheus brasileiro Anker, 2012 and to review the larval morphology (Zoea I) of the genus Alpheus Fabricius, 1798. Larvae were obtained from two females with embryos collected in an intertidal estuary in Cananéia, São Paulo state, Brazil. The published descriptions of all available Alpheus zoea I (only 14 spp.

First zoeal stage of the partner shrimp Periclimenes paivai Chace, with remarks on the genus Periclimenes O.G. Costa (Caridea, Palaemonidae.

The morphology of the first zoeal stage of Periclimenes paivai Chace is described and illustrated for the first time. Larvae were obtained from three females with embryos, caught in the type locality (Cananéia, São Paulo state, Brazil). The morphological characters are detailed and compared with all previous descriptions of larvae in the genus (P.