564 



ECOLOGY AND BEHAVIOR 



The size and seasonal distributions of C. carcharias caught in the Durban 

 area (summarized in Figure 10) make the segregation of small and large 

 specimens clear. Large sharks occur principally in the first half of the year 

 and smaller sharks in the second half of the year with a peak at about August 

 or September. This distribution reflects some movement or migration other 

 than that caused by seasonal temperature changes, otherwise more large 

 sharks should be caught during the period October to December, when water 

 temperatures are roughly equivalent to those of March to May. C. carcharias 

 differs from most of the large sharks found in the seas about southern Africa 

 in having a range that is basically warm temperate rather than tropical. The 

 actual nursery areas have still to be defined. As yet, virtually nothing is 

 known about the breeding habits. 



Scylliogaleus quecketti 



Scylliogaleus quecketti (Figure 11) is a small crustacean-eating shark with 

 demersal habits. Born at a length of about 34 cm, males are mature at 70 cm 

 and females at 80 cm with a maximum size of slightly more than a meter. All 

 known specimens of this species have come from shallow water off the Natal 

 and eastern Cape coasts, the great majority being adolescent or adult females. 

 Many of the latter have contained embryos, some full term, others still in 

 the earliest stages of development. Only two males, both adult, have been 

 recorded and the habitat of juvenile sharks of both sexes is unknown. Pre- 

 sumably it is in deep water away from the shore, possibly among reefs where 

 sampling by means of trawls is not possible. It is unlikely that a 



24 

 23 



224 



°c 



21 



20 



19 



4 



5 275cm 2 







8 



6 



4 



i 



2 

 



Q 



£Lil- 



T r - 



-l r - 



H 



< 275cm 



I I I I .  



M 



M 



= males I I = female 



Figure 10 Seasonal distribution of 58 Carcharodon carcharias taken in Natal waters 

 (mostly from the Durban area). Also shown are the monthly surf temperatures as recorded 

 at Durban. (After Figure 11 of Bass et al. 1975c.) 



