ROUGH-TOOTHED DOLPHIN (T) 



Steno bredanensis (G. Cuvier in Lesson 1828) 



Other Common Names 



Rough-toothed porpoise, goggle-eyed porpoise. 

 Description 



Rough toothed dolphins reach a length of at least 8 feet 

 (2.4 m). The coloration of the rough-toothed dolphins is quite 

 variable. Individuals are often dark gray to dark purplish 

 gray on the back with pinkish-white blotches on the sides 

 and belly. The flippers and flukes are dark and the belly is 

 white. Individuals are frequently scarred with numerous 

 white streaks. 



The most distinctive characteristic of the rough-toothed 

 dolphin is its beak, which is quite long and slender, may be 

 white or pinkish white along both sides, including one or both 

 lips and the tip of the snout, and is not separated from the 

 forehead by the transverse groove present in other long- 

 snouted dolphins. Because the forehead and the sides of the 

 head slope smoothly into the rostrum, when this animal is 

 seen from above or from the side, its entire head appears very 

 long and nearly conical. 



Natural History Notes 



Rough-toothed dolphins occur in small groups of 50 

 animals or fewer and are usually found off the edge of the 

 continental slope. They may ride the bow waves. 



May Be Confused With 



In their offshore habitat, rough-toothed dolphins are most 

 likely to be confused with Atlantic spotted dolphins (p. 104) 

 and with Atlantic bottlenosed dolphins (p. 128). They may 

 be distinguished from Atlantic spotted dolphins by the 

 following: 



Rough-Toothed Dolphin 



Atlantic Spotted Dolphin 



SNOUTS 



Long and slender; not clearly 

 demarcated from forehead. 



Moderate in length and 

 clearly demarcated from 

 forehead. 



Figure 149. — Captive rough-toothed dolphins in Japan. Note the distinctive, smoothly tapering head and the white 

 coloration of the sides and front of the snout. Rough-toothed dolphins are probably widely distributed in the offshore 

 waters of the tropics. The streamers on the backs of the animals are marker tags (see Appendix A.) (Photo courtesy of 

 Japanese Whales Research Iiutitute. ) 



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