ABSTRACT
The seasonal temporal sexual and size segregation of White Sharks, Carcharodon carcharias, at the Neptune Islands, South Australia, is described. Under baited conditions, using chum to attract sharks to the vessel, the sex and size of White Sharks were recorded over a 3-yr. period from April 2001 to February 2004. Sexual and size segregation was observed in this species. There was a high degree of interannual variability in the data with the number of subadult males increasing and mature males decreasing over the 3 yrs. of the study. An overall trend was observed for larger White Sharks to be recorded in the winter/spring months (June to September) and smaller sharks in other months. Sea-surface temperature appeared to be related to sexual and size segregation in this species. It was found to be negatively related to subadult and mature male numbers, whereas no signi¢cant relationships with temperature were found for females of either size grouping, although female abundance tended to cluster toward the higher temperature ranges (15.7-18.1°C). The signi¢- cantly lower temperatures in 2003 may explain the absence of females in this year. It is speculated that females may favor warmer waters to promote and accelerate embryonic development of young as a result of comparatively increased internal core body temperatures.
