Smale and Goosen: Reproduction and feeding of Triakis mega/opferus 



993 



ulirus homarus, appeared in the largest size class. 

 Although crustaceans were important prey of the 

 large sharks, they were less dominant in the diet. 



Teleosts became more important prey for larger 

 sharks. They included representatives from at least 

 10 families and 14 species (Table 1). They dominated 

 the prey of large sharks by mass (53.9%) and by num- 

 ber i.477c), whereas they contributed only 10.3% and 

 14.2% by mass for the medium and small-size classes, 

 respectively (Fig. 8). Only three species offish were 

 eaten by the smallest sharks, of which barred 

 fingerfin, Cheilodactylus pixi, was the most impor- 

 tant. Six species were taken by the medium-size class, 

 and twotone fingerfin (Chlrodactylus brachydactyhis) 

 was the most important. The diet of the large-size class 

 was dominated by several species, viz. seacatfish 

 (Galeichthys sp. ), cob (Ar-gyrosomiis inodorus). red tjor- 

 tjor (Pagellus bellottii natalensis), and blue hottentot 

 (Pachymetopon aeneum). The two largest teleost spe- 

 cies ingested, based on recalculated total length, were 

 a 336-mm sand steenbras (Lithognathus mormyrus) 

 and a 334-mm seacatfish (Galeichthys sp.). Both were 

 taken by sharks longer than 1500 mm TL. 



Cephalopods were the second most important for- 

 age category for medium-size sharks (Fig. 8). The 

 common octopus [Octopus vulgaris) and the squid 

 Loligo vulgaris reynaudii were the most important 

 species, making up 25.5% and 7.8% by mass, respec- 

 tively. Cephalopods were minor prey for the largest 

 class of sharks (4.6% by mass). 



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I I I I I I I I I I I I I I  r 1 ' I * I I 



3 6 9 12 15 18 21 24 

 Months 



Figure 7 



Mean size of normal embryos in each lit- 

 ter plotted against month of the year. 

 The arrow indicates a shift of large lit- 

 ters (empty circles) to the same months 

 one year later 



Elasmobranchs were relatively unimportant prey 

 of spotted gully sharks. One stomach had the remains 

 of a lesser sandshark (Rhinobatos sp.), another con- 

 tained remains of a brown catshark (Haploblepharus 

 fuscus ), and two contained catshark eggs. The occur- 

 rence of anomalous food items was very rare. Ined- 

 ible remains included a bryophyte (one stomach) and 

 an unidentified mussel (one stomach). 



In addition to ontogenetc variation in prey, prey 

 size increased with growth (Fig. 9). Cape rock crab 

 {Plagusia chabrus) was an important prey for sharks 



<999 



" 1.000-1.399 



Crustaceans 



Cephalopods 



Teleosts 

 Prey taxa 



Elasmobranchs Miscellaneous 



Figure 8 



Percentage mass of different taxa in the diet for different size classes of T! megalopterus. 



