Développement juvénile de Menippe nodifrons Stimpson, 1859 (Crustacea, Decapoda, Xanthidae) en laboratoire

Les huit premiers stades juvéniles de #M. nodifrons étudiés en laboratoire, ont été obtenus à partir d'élevage de larves provenant de femelles oeuvées collectées à Ubatuba, S.P., Brésil. Les expériences d'élevage ont été réalisées à une température de 24 (+ ou -) 1°C en eau de mer de salinité 34,5°/oo, utilisant comme alimentation des nauplii d'#Artemia salina et de petites portions de muscles de poisson. Dans ce travail sont présentées les descriptions morphologiques détaillées du premier stade juvénile, les caractères diagnostiques pour les autres stades obtenus, la durée de chaque stade et une analyse comparative avec des espèces semblables étudiées antérieurement, appartenant à la région sud-est du Brésil. (Résumé d'auteur

Range extensions along western Atlantic for Epialtidae crabs (Brachyura, Majoidea) genera Acanthonyx Latreille, 1828 and Epialtus H. Milne Edwards, 1834

The present study provided information extending the known geographical distribution of three species of majoid crabs, the epialtids Acanthonyx dissimulatus Coelho, 1993, Epialtus bituberculatus H. Milne Edwards, 1834, and E. brasiliensis Dana, 1852. Specimens of both genera from different carcinological collections were studied by comparing morphological characters. We provide new data that extends the geographical distributions of E. bituberculatus to the coast of the states of Paraná and Santa Catarina (Brazil), and offer new records from Belize and Costa Rica. Epialtus brasiliensis is recorded for the first time in the state of Rio Grande do Sul (Brazil), and A. dissimulatus is reported from Quintana Roo, Mexico. The distribution of A. dissimulatus, previously known as endemic to Brazil, has a gap between the states of Espírito Santo and Rio de Janeiro. However, this restricted southern distribution is herein amplified by the Mexican specimens

Développement juvénile de Menippe nodifrons Stimpson, 1859 (Crustacea, Decapoda, Xanthidae) en laboratoire

Les huit premiers stades juvéniles de #M. nodifrons étudiés en laboratoire, ont été obtenus à partir d'élevage de larves provenant de femelles oeuvées collectées à Ubatuba, S.P., Brésil. Les expériences d'élevage ont été réalisées à une température de 24 (+ ou -) 1°C en eau de mer de salinité 34,5°/oo, utilisant comme alimentation des nauplii d'#Artemia salina et de petites portions de muscles de poisson. Dans ce travail sont présentées les descriptions morphologiques détaillées du premier stade juvénile, les caractères diagnostiques pour les autres stades obtenus, la durée de chaque stade et une analyse comparative avec des espèces semblables étudiées antérieurement, appartenant à la région sud-est du Brésil. (Résumé d'auteur

Alometria no crescimento de Uca mordax (Smith) (Crustacea, Decapoda, Ocypodidae) na Baía de Guaratuba, Paraná, Brasil Allometric growth in the fiddler crab Uca mordax (Smith) (Crustacea, Decapoda, Ocypodidae) from Guaratuba Bay, Parana, Brazil

Um estudo do crescimento relativo da maior quela do macho e do abdome da fêmea foi realizado numa população do caranguejo chama-maré Uca mordax (Smith, 1870) ocorrente no extremo oeste da Baía de Guaratuba, Paraná, sul do Brasil. O comprimento da maior quela (CMQ) foi medido em 319 machos, e a largura do abdome (LAB) em 356 fêmeas. Adicionalmente, seis chama-marés sexualmente indiferenciados foram analisados. A largura da carapaça (LC) foi escolhida como dimensão de referência para ambos os sexos, a qual variou de 1,94 a 20,0 mm para machos, de 2,50 a 18,85 mm para fêmeas, e de 1,94 a 3,15 para os indivíduos sexualmente indiferenciados. A relação entre o LC e CMQ mostrou um ponto de inflexão em 11,70 mm LC nos machos, e entre LC e LAB, em 8,77 mm LC dentre as fêmeas. Os machos (média LC = 14,24 mm) atingiram tamanhos pouco maiores do que as fêmeas (média LC = 13,97 mm). O crescimento foi alométrico positivo durante toda a ontogênese de ambos os sexos, isto é, antes e depois da muda puberal. As equações das relações entre LC e CMQ nos machos foram: logCMQ = -0,542265 + 1,51.logLC para machos juvenis e logCMQ = -1,446281 + 2,37.logLC para machos adultos. Nas fêmeas, a relação entre LC e LAB foi: logLAB = -0,607282 + 1,22.logLC e logLAB = -0,912074 + 1,60.logLC, respectivamente, para juvenis e adultas. Estas dimensões estão relacionadas com as atividades reprodutivas da espécie. O nível de alometria do CMQ dos machos adultos de U. mordax foi o mais alto dentre as espécies do gênero, cujo crescimento relativo desta dimensão foi estudado. A proporção de machos destros foi estatisticamente a mesma daqueles sinistros (1:1).<br>Relative growth of the male major chela and female abdomen was studied in a population of the fiddler crab Uca mordax (Smith, 1870) from Guaratuba Bay, Parana, Southern Brazil. Major chela length (CMQ) was measured from 319 males, and abdomen width (LAB) from 356 females. Also six small sexually undifferentiated crabs were measured. Carapace width (LC) was the reference dimension for both sexes, which ranged from 1.94 to 20.0 mm for males, from 2.50 to 18.85 mm for females, and from 1.94 to 3.15 mm for sexually undifferentiated crabs. Relationship between LC and CMQ showed a transition point at 11.70 mm LC in males, and between LC and LAB, at 8.77 mm LC in females. Males (mean LC = 14.24 mm) showed a slightly greater size than females (mean LC = 13,97 mm). These dimensions had positive allometrical growth during all life for both sexes: before and after the puberal molting. Regressions between LC and CMQ in males read as: logCMQ = -0,542265 + 1,51.logLC for male juveniles and logCMQ = -1,446281 + 2,37.logLC for male adults. In females, the regressions between LC and LAB were: logLAB = -0,607282 + 1,22.logLC for juveniles and logLAB = -0,912074 + 1,60.logLC for adults. These body dimensions are related to reproductive activities of this species. The level of allometry in CMQ of adult males was the highest among Uca species which relative growth of this dimension is known. The handedness had a proportion of 1:1 between right-handed and left-handed males