Juvenile development of the crab Bathyrhombila sp (Crustacea, Decapoda, Pseudorhombilidae) from megalopae obtained in the neuston

Abstract

The identification of juvenile brachyurans obtained from the wild is extremely difficult, because the juveniles of most species have different features from the adults. Furthermore, studies on the post-embryonic development of brachyuran crabs are few. Nothing is known about the juvenile development of members of the Pseudorhombilidae. The present study analysed the growth of Bathyrhombila sp., providing morphological details for the identification of its developmental stages. Decapodites were collected using neuston nets in the region of Ubatuba, state of São Paulo, Brazil. The larvae were transported to the laboratory, cultivated separately in labelled acrylic containers with filtered, aerated seawater, and fed with Artemia sp. nauplii. Eleven juvenile stages were obtained for males, and 14 for females. The morphology and number of setae on the appendages are described, mainly for the first juvenile stage. Secondary sexual characters develop from the fourth juvenile stage. Compared with previously studied crab species, Bathyrhombila sp. and Eurytium limosum have a similar carapace form. Also, in Bathyrhombila sp. the endopod of the second maxilliped has five segments, whereas the other species of Xanthoidea and Eriphioidea described so far have four.