Reproductive biology of the edible jellyfish Catostylus mosaicus (Rhizostomeae)

The reproductive biology of the jellyfish Catostylus mosaicus (Quoy and Gai mard 1824) (Scyphozoa: Rhizostomeae) was investigated in New South Wales, A ustralia. Medusae were gonochoristic. There was a 1:1 ratio of male and fem ale medusae and there was no evidence of sexual dimorphism. Oocytes arose f rom the gastrodermis and maintained contact with the gastrodermis, via trop hocytes, throughout gametogenesis. Spermatogenesis occurred within follicle s that arose from invagination of the gastrodermis. Detailed sampling of go nads over a period of 3.25 yr in Botany Bay, and over 2.5 yr in Lake Illawa rra, indicated that gametogenesis occurred almost continuously during the y ear. Oocytes were smaller, or were absent from the ovaries during 3 of the 4 winters sampled at Botany Bay and during all 3 winter periods sampled at Lake Illawarra. Comparisons were made with other locations, although these were sampled less frequently. When medusae were present at a location, simi lar trends were observed. The size at which medusae matured varied, but dur ing non-winter periods and at two locations, all medusae exceeding 130 mm d iam were considered mature.