Juvenile Development of Clibanarius sclopetarius (Herbst, 1796) (Crustacea: Paguridea: Diogenidae) in the Laboratory

Abstract

The present study deals with the juvenile morphology of Clibanarius sclopetarius (Herbst, 1796) reared in the laboratory. Ovigerous females were collected in intertidal and shallow estuarine waters at Sao Sebastiao on the northern coast of the state of Sao Paulo, Brazil. Hermit crabs were maintained in filtered sea water in a climatically controlled room at 25 ? 2?C until hatching. Larvae were cultured individually with nauplii of Artemia salina as food. Ten or more crab instars after megalopa were obtained, of which five were studied intensely and their most representative structures illustrated and described. The developmental period of C. sclopetarius until the fifth juvenile crab instar was completed in 171 days (mean value) from hatching. Sexual dimorphism was evidenced by the appearance of secondary sexual characteristics in the fifth juvenile instar. The postembryonic development of decapod crustaceans is generally characterized by three distinct stages: a zoeal or larval stage involving several instars separated by ecdysis which vary in number according to the species, a megalopa stage consisting of a single instar, and a juvenile or postlarval stage starting from the first ecdysis undergone by the megalopa, and continuing through a varying number of juvenile crab instars, until the definitive adult form is attained. The end of the juvenile stage is not as distinct as that of the larval one, because of the difficulty in recognizing when the animals are functionally capable to reproduce. It could be defined as a period in which the external morphological structures become similar to those of the adults.