Sexual maturity and fecundity of Octopus maorum in southeast Tasmania

Female Octopus maorum caught between March and October 1996 in Eaglehawk Bay, southeast Tasmania, were in various stages of ovarian development, but most were close to sexual maturity. Of the males caught, 91% were mature, and produced spermatophores, but 20% of these males produced spermatophores without a sperm rope. Females ready to lay eggs were caught in all months of the study except May and August. The number of eggs in their ovaries ranged between 56,000 and 232,000; there was no clear relationship between fecundity and ovary weight. Likewise, ovary weight was not correlated with body weight. Histological examination of O. maorum eggs showed that the process of oogenesis in this species is very similar to that of other cephalopods. O. maorum oocytes change shape during their development, with mature oocytes most closely resembling those of Pteroctopus tetracirrhus. An additional collection of male O. maorum off the east and west coasts of Tasmania showed that males over 830 g have developing hectocotyli and can produce spermatophores. Furthermore, dorsal mantle length, genital bag weight and spermatophore length were highly correlated with body weight in these specimens.