c. Ventral grooves absent, but i-] deep longitudinal creases present 

 on chin or throat; viewed dorsally or laterally head nearly tri- 

 angular, mouthline slightly arched; dorsal fin absent, but small 

 hump present, tollowed by 6-12 ridges or crenulations; maximum 

 body length 14.0 m; m8-i8o white to vellovvish-white baleen 

 plates per side; body mottled gray. 



* Gra\' Whale, Eschruhlius rohuslus (A) 

 ;. a. Ventral grooves end before navel Go to 4 



b. Ventral grooves extend to or beyond navel Go to 5 



4. a. 50-70 ventral grooves [2] longest often ending between flippers; 



baleen less than 21 cm long, mostly white or yellowish white 

 (some posterior plates may be dark) with 15-25 white bristles per 

 centimeter; 251-285 plates per side [i] head coloration sym- 

 metrical; maximum body length 10 m; conspicuous white band 

 on each flipper; viewed laterally, head flat; viewed dorsally, head a 

 slim, pointed triangle. 



* Minke Whale, Bulacnoptcra aculoroslrata (A) 



b. J 2-60 ventral grooves, longest ending well short ot navel; baleen 

 less than 80 cm long, black (^some antenormost plates may be 

 white) and with 55-60 fine silky light bristles per centimeter; 

 219-402 plates per side; head coloration symmetrical; viewed 

 laterally head slightly arched near tip; viewed dorsally head 

 slightly rounded on tip; maximum body length i6m; flippers all 

 dark, 



* Sei Whale, Balainoplira hortnlts (B) 



5. a. Flippers one-fourth to one-third of body length, knobbed on 



leading edge ( two prominent knobs ); less than 2 5 broad, conspic- 

 uous ventral grooves, longest extending at least to navel; head 

 covered with numerous knobs; barnacles often attached to head, 

 including lips; baleen less than 80 cm long, ash black to olive 

 brown (sometimes whitish 1, with 10-55 gravish-white bristles per 

 centimeter; 570-400 plates per side; maximum body length |ust 

 over 16 m, 



* Humpback Whale, Migapler^ novm-afij/iiif (A'\ 



h. Flippers less than one-fihh ot body length and lack knobs; from 40 

 to 100 fine ventral grooves, longest extending at least to navel; head 

 lacks knobs Go to 6 



6. a. Three conspicuous ridges on top of head, a mainridge trom 



blowholes to tip ot" snout, one auxiliary ridge along each side of 

 main ridge [4]; 40-50 ventral grooves; 255-565 slate-gray baleen 

 plates vv'ith 15-55 dirty gray bristles per centimeter; maximum 

 body length 14 m; head coloration symmetrical. 



* Bryde's Whale, Balacnoplera cdim (B) 



b. Only one prominent ridge on head [4], from |ust in front of 

 blowholes torward towards tip ot snout; 55-100 ventral grooves 

 Go to 7 



[1] Ventral grooves are longitudinal tolds located on the chin, throat 

 and abdomen of rorqual whales. Do not confuse them with the 2-5 

 deep longitudinal creases found on the throat of gray whales (item 2.c.) 

 or the "V" shaped creases on the throat ot dwart sperm whales (item 

 I i.b) and beaked whales (items 12, a, 14, and 1 5). Such creases, though 

 variable in depth, orientation, and length, always end on the throat, 

 well short of the naval. 



[2] Counts ot ventral grooves are made between the flippers and do not 



include shorter grooves often found on the side of the head and on the 



side above the flipper. 



[5] Minke whales in some areas have been reported to have as many as 



500-525 plates per side. 



[4] Blue and fin whales have taint lateral ridges, as well. 



55 



