Sepia australis is most abundant in the eastern South Atlantic between Luderitz and St. Helena Bay (about 27-35°S in 100-200m). There seems to be no link between the variation in abundance of S. australis and that of its most important predator, the shallow-water Cape hake, Merluccius capensis. The variations in abundance of S. australis and one of its most important prey species, the stomatopod crustacean Pterygosquilla armata capensis, show simultaneous changes, suggesting that both species respond to the same environmental factors. Mantle length, total weight, gonad weight, and sex ratio of Sepia australis vary from year to year and by region off the west coast of southern Africa. Animals from the south coast (eastward of Cape Point) were very different: length-weight relationhips were found to be similar in slope and intercept for both sexes and within each sex between years and regions off the west coast, but different for the south coast
