Ivindomyrus opdenboschi Taverne and Géry, 1975
Species overview
Larger-sized fish, body moderately deep, occipital region may be quite big; head much varying in shape, front sloping, end of snout round or steeply sloping; mouth subterminal.
Size observed: 274 mm SL.
I. opdenboschi(measurements)
Taxonomic description
-Body rather bulky, moderately short, laterally compressed, body depth 30-35 % SL, greatest depth more or less above pelvic fin.
-Head length 26-30 % SL, head depth 25-31 % SL, 76-93- % body depth, measured above opercular cleft, much less above nostrils.
-Outline of back slightly curved from neck to dorsal fin; upper profile of head sloping down, slightly convex or concave.
-End of snout rounded or steeply inclined; underside of head straight or slightly concave.
-Snout moderately long, moderately projecting mouth, 22-29 % head length, 39-58 % postorbital length; upper jaw on a level between pectoral fin and underside of head.
-Mouth wide, 21-22 % head length, subterminal, its edge below posterior nostril; lips rather thick.
-Chin with slight submental swelling.
-Teeth slightly notched, 4-7/5-8, often hidden in the gums.
-Nostrils separate, posterior one slightly oval and slightly more than two times as far from eye as from anterior nostril; posterior nostril on a level with lower margin of eye, anterior slightly above, axis of nostrils cuts axis of head at an angle of about 30°.
-Eye diameter 8-10 % head length.
-Opercular cleft curved, 30-43 % head length, 33-40 % head depth.
-Dorsal fin 20-24 fin-rays, base of D 15-21 % SL, anal fin 26-30 rays, base of A 25-26 % SL, origin of D behind origin of A, end of D before end of A; both D and A are moderately steep inclined to caudal peduncle.
-Predorsal length 61-64 % SL, preanal length 57-61 % SL.
-Pectoral fin pointed, extending beyond middle of pelvic fin. V is nearer P than A. -Caudal fin large, pointed, scaled lobe as well as membrane. 50-57 scales in lateral line; 12 round caudal peduncle.
-Caudal peduncle slim, 17-22 % SL, its depth 5-6 % SL, 25-30 % its length.
Type locality
»Rapides de Loa-Loa, en aval de Makokou«, (00° 27 ‘N 12° 48 ‘E) and »Liboumba, jusqu’á une dizaine de kilomètres de son embouchure [opposite Makokou], Gabon.«
Distribution
Ivindo river and tributaries, type locality; the Ivindo is a tributary of the Ogowe, Gabon.