175 



KEY TO MARINE MAMMALS (Cont.) 



40' Blunt snout and short thick body; dorsal fin usually triangular 

 but posterior margin nearly perpendicular to the back, while an- 

 terior margin not so steep; dark above, light below; no sharply 

 delimited white area on flanks; no prominent ridge running forward 

 from flukes; teeth usually with broad crown (flattened laterally, 

 spatula-shaped), not buried in gums; diameter of teeth in the middle 

 of the jaw >1 mm at the gum line; vertebrae number about 68. 



HARBOR PORPOISE 



41 Beak long, the distance from its tip to the eye center is less than 

 2.6 times the beak length (from tip to beginning of forehead); beak 

 length is greater than one- twentieth the total body length. 42 



41' Beak moderate to short, the distance from beak tip to the eye center 

 greater than 2.7 times the beak length; beak length is less than one 

 twenty-fifth the total body length. 43 



42 A dark streak running from the flipper base toward chin; roof of 



mouth (palate) with two longitudinal grooves. COMMON DOLPHIN 



42' A dark streak (often indistinct) running from flipper to corner of 

 mouth area or to base of eye, and frequently circling eye (variable); 

 roof of mouth without grooves; up to 2.7 m in length. 



SPOTTED AND STRIPED DOLPHINS (Stenella spp; 



skull required for positive identification) 



43 Each side of upper jaw has 19-26 teeth, 19-25 teeth on each side of 

 lower jaw; diameter of a tooth from the middle of the jaw 6-11 mm; 

 beak not white, up to 7 cm long in adults; no ridge on back from 

 flukes forward; gray or dark blackish, belly lighter. 



BOTTLENOSE DOLPHIN 



43' Each side of upper and lower jaws has 27-40 teeth; diameter of a tooth 

 from center of jaw, 4-5 mm; if teeth fewer (up to 22 per side of jaw) 

 and their diameter is greater (up to 6-7 mm), then beak white; beak 

 from tip to forehead is up to 5 cm long in adults; sides of body 

 flattened just before flukes with a distinct ridge along top; black 

 back, striking light gray sides and white belly. 



PACIFIC WHITE-SIDED DOLPHIN 



