ISLAGRANDE (DECAPODA: THALASSINIDEA: CALLIANASSIDAE) UNDER LABORATORY CONDITIONS

Descriptions of the zoeal and decapodid stages of the ghost shrimp Callichirus islagrande were based on laboratory cultures from a population inhabiting the coast of Louisiana. Whereas morphological studies were based upon animals from mass cultures, 40-120 larvae from each of 8 parental females were reared individually to obtain stage-duration data. Larvae passed through 4 or 5 zoeal stages before molting to the decapodid stage. The proportion of individuals that molted to a fifth zoeal stage varied widely (9-89%) between clutches of different parental females. The first juvenile stage was usually reached 16-20 days after hatching, and durations of larval stages were similar in larvae from different females. Morphological comparisons with congeneric species revealed larvae of C. islagrande to be more similar to larvae of C. garthi, a species from the coast of Chile, than to larvae of a Gulf of Mexico population of Callichirus major. In a recent revision of the Callianassidae (Manning and Felder, 1991), the genus Callianassa was restricted from its former worldwide status to certain eastern Atlantic populations based on morphological characters. American species that were previously included in the genus Callianassa were placed in a number of genera, based on life history and morphology, as in the case of the genus