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-This work aims to estimate the average size at the onset of morphological and physiological sexual maturity and the reproductive period of Callinectes danae. Specimens were captured from a shrimp fishing boat equipped with a trawl net from March 2009 to February 2010. After sorting, crabs were sexed, and the following morphometric dimensions were measured: carapace width (CW), length and height of the major (MAP and HMAP), and the minor cheliped propodus (MIP and HMIP) for both sexes, and the abdominal width for females (AW). The onset of morphological maturity was estimated with the REGRANS program, in which the inflection point is calculated. The size at the onset of physiological maturity was determined by logistic regressions fitted to the relationships between the percentages of juvenile and adult individuals of each CW. A total of 893 individuals were sampled. Of these individuals, 389 were males, 472 non-ovigerous females, and 32 ovigerous females. The CW ranged from 19.81 to 117.17 mm for males, 19.91 to 113.11 mm for non-ovigerous females, and 70.55 to 88.60 mm for ovigerous females. Morphological sexual maturity was attained at 86.47 mm CW (males) and 67.87 mm CW (females). The size at the onset of physiological maturity was calculated to be 86.50 mm CW (males) and 67.00 mm CW (females). Due to the closeness of these values, both techniques were deemed suitable for determination of the onset of sexual maturity in C. danae. This species reproduces throughout the year, but reproduction is more intense during the winter. Mature males are present throughout the year. Data from this investigation will help resource managers to develop strategies that will ensure a sustainable harvest of this important species of swimming crab in southern Brazil.

An identification key was produced for caprellid species recorded from the coast of Paraná and Santa Catarina states, Southern Brazil. Analyzed specimens are part of scientific collections or were obtained from nature, within these states. Nine caprellid belonging to the family Caprellidae, from which eight of Caprellinae -Caprella danilevskii, Caprella dilatata, Caprella equilibra, Caprella penantis, Caprella scaura, Mayerella sp., Paracaprella pusilla e Pseudaeginella montoucheti -and one Phtisicinae -Phtisica marina -were treated in the present study.

A new species of caprellid, Pseudaeginella arraialensis, is described from Arraial do Cabo, Rio de Janeiro, Brazil. Abundant material was collected in Praia do Forno, associated to hydroids and algae of natural rocky substrata and fouling communities of artificial floating structures. The new species can be distinguished easily from the remaining species in the genus mainly by the pattern of dorsal projections, and by the setose antennae and gnathopod 2 in males. The dietary analysis revealed that the species is omnivorous, with a high contribution of small crustaceans in its diet. Detailed figures showing ontogenetic development and intraspecific variation of P. arraialensis are also included.

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Malacofauna de três fitais da Praia de Caiobá, Matinhos, Paraná

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Resumen.-La diversidad del espacio y la variabilidad de las condiciones ambientales que afectan la calidad del hábitat para los organismos son factores determinantes en la selección de un hábitat ideal. El presente estudio tuvo como objetivo determinar la selección del sustrato del anfípodo caprélido Caprella dilatata, en ambientes naturales al largo de la costa del sur de Brasil y en condiciones de laboratorio. Se contabilizaron 31 sustratos biológicos distintos que albergaban a invertebrados, la mayoría fueron sustratos algales. C. dilatata fue registrada en once de estos sustratos, y resultó ser especie dominante únicamente en algas finamente ramificadas, ascidias, briozoos y en las superficies de las boyas y cuerdas. Los experimentos de laboratorio para selección de sustrato por C. dilatata se realizaron utilizando dos y cuatro especies de algas que tenían contrastante ramificación; Gracilaria cervicornis, Pterocladia capillacea, Sargassum cymosum y Ulva fasciata. En el primer experimento, caprélidos fueron trasladados a tres acuarios que contenían combinaciones variadas de dos sustratos de algas con un total de nueve combinaciones. Para el segundo experimento (cuatro algas), todas las especies de algas se combinaron en cada acuario. Los anfípodos obtenidos para experimentos en laboratorio mostraron el color del dermatoesqueleto siempre muy similar al color de las algas. Hubo una fuerte preferencia de caprélidos por el sustrato original. A pesar de la morfología cosmopolita de C. dilatata para la selección del sustrato, los individuos se encuentraron principalmente en sustratos estructuralmente complejos, y demostraron la importancia del camuflaje en estos caprélidos.Palabras clave: Caprellidae, algas, sustratos artificiales, condiciones de laboratorio Abstract.-The diversity of space and the variability of environmental conditions that affect habitat quality for organisms, are determining factors in the selection of an ideal habitat. The present study aimed to understand the substrate selectivity of a caprellid amphipod, Caprella dilatata, in natural environments along the southern Brazilian coast and in laboratory conditions. A total of 31 biological substrates sheltering invertebrates were collected across various localities. C. dilatata was recorded in 11 substrate samples, and was a dominant species only in finely branched and softly surfaced algal substrate, ascidian and bryozoan colonies, and the surfaces of buoys and ropes. Laboratory experiments for substrate selection by C. dilatata were performed under two conditions: two-algal substrates and four-algal substrates. The phytals of Gracilaria cervicornis, Pterocladia capillacea, Sargassum cymosum and Ulva fasciata were selected for the experiments due to their contrasting degrees of ramification. In the first experiment (two-algal substrates), caprellids were transferred to three aquaria containing varied combinations of two algal substrates with a total of nine combinations. For the second experiment (four-algal substrates), all species of algae we...