BRIDLED DOLPHIN (T) 



Stenella frontalis (G. Cuvier 1829) 



Other Common Names 



Bridled spotted dolphin, Cuvier's dolphin, gamin (St. 

 Vincent), bridled porpoise. 



Description 



Bridled dolphins, the second species of spotted dolphins in 

 the western North Atlantic, reach an adult length of at least 

 7 feet (2.1 m). Like the other, the Atlantic spotted dolphin 

 (p. 104), bridled dolphins are characterized by light grayish- 

 white spots on the dark dorsal portions of the body and dark 

 spots on the light ventral surface. Other details of the 

 coloration differ somewhat. Bridled dolphins are dark gray 

 on the back, fading to lighter gray on the sides and belly. 

 They lack the spinal blaze characteristic of Atlantic spotted 

 dolphins. Except on the head, the border between the back 

 and side colors is indistinct. On the head, the cape (the dark 

 color of the! top of the head) is distinct. In the light g^ay of 

 the side of the head are the markings from which the species 

 derives its common name, "bridled dolphin." These are a 

 black circle around the eye with an extension to the junction 

 (apex) of the rostrum and the melon (present in nearly all 

 dolphins) and a broad black stripe from the origin of the 

 flipper to the corner of the mouth. This mouth-to-flipper 

 stripe tends to fade as spotting increases. Both the upper 

 and lower lips are white or pinkish. 



Natural History Notes 



Virtually nothing is known of the natural history of 

 bridled dolphins except that they have been observed in small 

 herds of from 5 to 30 individuals and sometimes ride the bow 

 wave of a vessel. 



May Be Confused With 



At sea, bridled dolphins may be confused with Atlantic 

 spotted dolphins or spinner dolphins. Differences by which 

 they may be distinguished from the first are tabularized on 

 p. 105. Differences between spinner and bridled dolphins 

 permitting identification at sea are as follows: 



Bridled Dolphin 



Spinner Dolphin 



COLORATION 



Distinct cape on top of head; 

 side of head light gray; 

 distinct stripes from flippers 

 to corner of mouth and from 

 dark circles around eye to 

 apex of melon. 



Dark gray on back; tan or 

 yellowish tan on sides; white 

 on belly. 



BEAK 



Shorter and more slender; all 

 black; lips white. 



Extremely long and slender; 

 dark gray to black on top, 

 white below; lips black. 



DORSAL FIN 



Uniformly dark gray. 



Distribution 



Often lighter gray in middle, 

 dark around border. 



Bridled dolphins occur in tropical and subtropical waters 

 primarily near coastal areas and islands, but are best known 

 from the West Indies. They have been reported from the 

 Antilles, from Texas, and from Florida north to North 

 Carolina. It has been speculated that this species replaces the 

 Atlantic spotted dolphin around the West Indies. 



Bridled dolphins have not yet been described from the 

 South American coast. 



Stranded Specimens 



Bridled dolphins have from 29 to 34 teeth in each upper 

 jaw and from 33 to 36 in each lower jaw. They can be 

 distinguished from spinner dolphins, which have 46-65 teeth 

 in each jaw, by this character alone. 



They may be distinguished from spotted dolphins only if 

 the color pattern of the head is clearly visible. If it has faded, 

 the specimen will probably require museum preparation and 

 examination before it can be positively identified. 



108 



