110 Commercial Shark Fishing in the Caribbean Area 



Figure 38 



Family Triakidae, Smooth Dog Fishes. Only five gill open- 

 ings; two dorsal fins and an anal; the base of the first dorsal 

 wholly in front of the pelvics; caudal less than 1/4 of the total 

 length of the shark, its axis only a little raised; with or without 

 a small lower lobe; lower ridges along the sides; the fourth or fifth 

 gill opening over the origin of the pectoral ; the nostril with or 

 without a barbel ; the eye does not have a nictitating ("winking") 

 membrane inside the lower lid. Teeth small, several series in 

 service simultaneously, either low and rounded or with 3 to 4 

 distinct cusps. 



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

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

 rounded and without definite cusps. 



Figure 38. Mustelus norrisi, Florida Dog Fish. 



Description : This very closely resembles Figure 39, but it is 

 easily distinguished from it by the facts that the mid-point of the 

 base of its first dorsal fin is considerably nearer to the origin of 

 its pelvics than to the axil (armpit) of its pectoral (almost the 

 same distance from these two points in the M. cams) and that the 

 lower lobe of its caudal is sharp pointed and directed rearward 

 (rounded in M. cants). 



Color: Gray above; paler or dirty white below; without any 

 conspicuous markings. 



Size: Matures at 2 to 3 feet; maximum size not known. 



Habits: Nothing known. 



Range: While it is known possibly only from southern Florida, 

 it is to be expected throughout the West Indian-Caribbean region. 

 Hence it is included here as an aid to identification. 



