"A . guttatus " is easily differentiated from other members of the " A . ischnosoma " group by a slender ( vs . moderately thick ) humeral process ( maximum width 10.0 & ndash; 11.8 % its length vs . 13.2 & ndash; 18.4 ) . " A . mahakamensis " is differentiated from other members of its group by a rounded ( vs . angular ) anterior margin of the anal fin, and a more slender body . " A . septentrionalis " can be differentiated by members of the " A . ischnoma " group by a smaller dorsal to adipose distance ( 4.4 & ndash; 5.7 % standard length vs . 6.2 & ndash; 9.8 ), fewer branchiostegal rays ( 4 vs . 5 & ndash; 6 ) and an almost uniformly cream colour pattern with few very small brown spots ( vs . a variegated colour pattern with numerous brown patches ) . " A . strigosus " can be differentiated from members of the " A . ischnosoma " species group by a rounded ( vs . angular ) posterior margin of the adipose fin and a more slender body; the genital papilla in male " A . strigosus " is also morphologically different from other members of its species group ( short and thick vs . long and thin ) . " A . ischnosoma " is distinguished from other members of the " A . ischnosoma " group by a greater distance between the dorsal fin and adipose fin ( 9.0 & ndash; 10.1 % SL vs . 4.4 & ndash; 8.7 ) and a greater exposure of the premaxillary teeth when the mouth is closed ( one-third vs . less than one-fifth to none ) . " A . gyrinus " can be distinguished from its congeners by a concave posterior margin of the pectoral fin.
