112 Commercial Shark Fishing in the Caribbean Area 



Figure 39 



Family Triakidae, Smooth Dog Fishes. 



Genus Mustelus, Smooth Dog Fishes. The nostril is not con- 

 nected with mouth and docs not bear a barbel; the teeth are low, 

 rounded and without definite cusps. 



Figure 39. Mustelus canis, Common Smooth Dog Fish. 



Description: Trunk slender; snout moderately long and blunt- 

 tipped; eye rather large; gill openings noticeably short, a little 

 longer than the horizontal diameter of the eye; the teeth (the most 

 distinctive feature of the genus) low, with bluntly rounded apex 

 directed a little toward the corners of the mouth, similar in the 

 two jaws, but a little more numerous in the lower (about 80) than 

 in the upper (about 75), in mosaic arrangement, several series 

 being in service simultaneously; mid-point of the base of the first 

 dorsal about as near to the axil (armpit) of the pectoral as to the 

 origin of the pelvics ; second dorsal 2/3 to 4/5 as high as the first 

 dorsal ; pectoral with nearly straight distal margin and with 

 rounded corners. 



Color: Plain olive-slaty or brownish gray above, with the mar- 

 gins of the fins paler; yellowish or grayish white below. 



Size: Born at a length of 14 to 15 inches, it matures at three 

 feet or less and occasionally grows to about five feet. 



Habits: An inshore species usually in depths of less than ten 

 fathoms and often close in to the land in bays and harbors, occa- 

 sionally entering fresh. water; feeding chiefly on the larger Crusta- 

 cea, such as crabs and lobsters, of which it is a destructive enemy; 

 also on squid and on any small fish that may be available. On the 

 northern part of its range, mating takes place in late summer and 

 the young arc born between early June and mid-July. The breed- 

 ing season of the southern stocks of the species is not known. 



Range: Western Atlantic. North abundantly to Cape Cod or 

 still farther as a stray; south to Central Brazil and Uruguay. This 

 species is known in Cuban waters, around Jamaica and at Trinidad 

 and is to be expected throughout the West Indian-Caribbean 

 region. Very little, however, is known about its occurrence there. 

 By contrast, it is one of the commonest of sharks along the coast 

 of the United States from North Carolina to southern New Eng- 

 land, where it is a regular migrant, north in spring, southward 

 again in autumn. Present indications also are that there is but 

 little interchange between the northern and southern populations, 

 for it does not seem to occur at all along the east coast of Florida. 



