SPERMATOPHORE AND SPERMATOZOAL MORPHOLOGY IN THE PORCELLANIDAE .2. THE GENERA PETROLISTHES AND POLYONYX (DECAPODA, ANOMURA)

The porcellanid genera Petrolisthes and Polyonyx are shown to have dif fering spermatozoal morphology reflecting an apparently natural divisi on of the family previously suggested on adult and larval somatic morp hology. Species investigated in the genus Petrolisthes have spermatozo a with a globular nucleus and autapomorphic opercular ridge and tubula r ring structure within the acrosomal vesicle. Spermatozoa of Polyonyx transversus (Haswell) have a long ''taillike'' nucleus penetrated thr oughout by a central microtubular core. This latter spermatozoal morph ology is shared with other members investigated in the ''Porcellana-gr oup,'' (Aliaporcellana and Pisidia). All the Porcellanidae investigate d share a suite of spermatozoal characters that unite them (superior a crosomal vesicle; broad, centrally perforate operculum; 4 or more exte rnal microtubular arms; perforatorial chamber wall folded into corruga tions or septa; dense perforatorial cone; posterior perforatorial ring and divided inner acrosome zone). A unique spermatophore morphology, consisting of a tubular extension of the anterior end of the ampulla, is described for representatives in the genus Petrolisthes.