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UNDERWATER GUIDE TO MARINE LIFE 



Fig. 59. Smooth dogfish. 



in a pavement and are adapted for shell crushing. Thus, it is a crab-eater 

 primarily, though a few lobsters are taken. It also takes small fishes, squids, and 

 some molluscs and worms. It may scavenge. This is the fish on which experi- 

 ments on shark feeding methods have been done. Smell is the chief aid for find- 

 ing food, the shark moving its head from side to side and therefore sensing food 

 alternately more strongly with one nostril than the other until the direction of 

 the food is detected. It has been shown that plugging one nostril causes the 

 fish to take much longer to find food. This shark is viviparous. As many as 

 twenty-seven foot-long young are born in June and July. The gestation period 

 is ten months. 



Similar Species: The gray smooth hound, Mnstelus californicus, is found 

 from northern California to Baja California and the sicklefin smooth hound, 

 Mustalus lunulatus, from San Diego to Colombia. Both are very much like 

 the East Coast species in habits and appearance. 



Fig. 60. Leopard shark. 



LEOPARD shark: Triakis semifasciata 



Size: Females mature at Wi feet and grow to 5 feet. Males grow to 3 feet. 



Distribution: Oregon to Baja California. 



Identification: The pattern of black crossbars and spots is unmistakable. 



Habits: This is a bay and shallow-water shark similar to the smooth dogfish. 

 Although small, this shark is easily incited by the presence of blood and will 

 bite. 



Similar Species: The brown smooth hound Triakis henlei, looks very much 

 like the Mustelus species. It is very common in San Francisco Bay and other 

 enclosed California bays. 



