Biology of Octopus vulgaris off the east coast of South Africa

The biology of Octopus vulgaris Cuvier inhabiting subtropical littoral reefs off the east coast of South Africa was investigated. Analyses of stomach contents and lair middens revealed that the mussel Perna perna was the dominant food organism. Growth rate of captive individuals was higher than has previously been recorded but food conversion was lower. Females became sexually mature at 900 g which is estimated to be attained in 3.6 months. Males became sexually mature at 400 g, which is estimated to be attained after 3 months. Results indicate that females live for 9-12 months and have the potential to reach 4 000 g in 240 d while males live for about 12-15 months and have the potential to achieve 4 000 g in 290 d. Mating and breeding occurred throughout the year although evidence for the seasonal migration of females is presented and discussed in relation to breeding and feeding behaviour. © 1981 Springer-Verlag.