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Sucker Key (Key to Adult Suckers >150 mm)
| 1a) |
Snout long, bullet shaped, when viewed from below it projects beyond the upper lip (Fig. A); lower lips large and, in profile, their hind margins extends back to, or beyond, the middle of the nostril (Fig. C); dorsal fin with 9-11 rays; scales small, more than 90 along the lateral line
-> Longnose sucker, Catostomus catostomus |
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| 1b) |
Snout short, blunt, when viewed from below it scarcely projects beyond the upper lip (Fig. B) lower lips moderate and, in profile, their hind margins barely reach the front half of the nostril (Fig. D); dorsal fin with 10-17 rays; scales large, fewer than 75 along the lateral line
-> see 2 |
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Figure A |
Figure B |
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Figure C |
Figure D |
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| 2a) |
Dorsal rays usually 10-13; the dorsal profile of the body gradually tapers back from the dorsal fin (Fig. E) to the relatively deep caudal peduncle (its depth usually more than half the width of the dorsal fin base)
-> White sucker, Catostomus commersoni |
| 2b) |
Dorsal rays usually 13-16; the dorsal profile of the body steeply tapers back from the dorsal fin (Fig. F) to a relatively narrow caudal peduncle (its depth usually less than half the width of the dorsal fin base)
-> Largescale sucker, Catostomus macrocheilus |
Figure E |
Figure F |
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