Suttkus and Mettee (1998) followed Hubbs and Lagler (1958) in presenting predorsal
scale counts for species of Mendia.
Few tripterygiid species have scales in the predorsal
highly arched back, strongly keeled predorsal
region, straight ventral contour (Douglas, 1974).
, pre-anal and pre-pelvic lengths are taken from the upper lip to the anterior origin of the respective fin.
Origin of first dorsal fin slightly posterior to pelvic-fin base, the predorsal
Number of scales in lateral series varies from 34 to 49 (mode = 40); predorsal
scales 11- 13.
Diagnosis: A species of melanotaeniid rainbow-fish distinguished by the following combination of characters: dorsal rays IV to VI + 1, 1 3- 16 (usually V + 1,14 or 15); anal rays 1,23-27 (usually 25 or 26); pectoral rays 13-15 (usually 14 or 15); lateral scales 37-39 (usually 38); transverse scales 9 or 10; predorsal
scales 17-19; circumpeduncular scales 12 or 13; total gill rakers on first arch 15-19 (usually 17 or 18); total scales covering preoperculum 1216 (mean 14.
A species of Synodus differentiated from its congeners by the following combination of characters: dorsal-fin rays 11 or 12 (rarely 11); anal-fin rays 11; total caudal rays 41-42; dorsal segmented caudal rays 9; ventral segmented caudal rays 10; dorsal procurrent caudal rays 12; ventral procurrent caudal rays 10-11; pelvic-fin rays 8; pectoral-fin rays 11 or 12; total vertebrae 47-49, modally 49; predorsal
vertebrae 12 or 13; pored lateral-line scales 45-48; median predorsal
scales 12 or 13; scale rows on cheek 4-6; eye large, 4.
Dorsal rays XI,9; anal rays III,9; pectoral rays 15; lateral-line scales 14-16 + 6-9; median predorsal
scales 5; horizontal scale rows on cheek below eye 2; gill rakers 14-17; body depth 2.
Sexual dimorphism also is observed with respect to maturity: males develop larger predorsal
adipose flaps than females at maturity, and males mature at older ages and larger sizes than do females (Grimes et al.
Other diagnostic features include 13 dorsal soft rays, 14 anal soft rays, first dorsal fin relatively short with no elongate rays, 51-55 longitudinal scales, 17-18 predorsal
scales, and a lanceolate caudal fin.
The following characters met the assumptions required for ANCOVA: head length, snout length, orbit length, interorbital width, postorbital length, upper jaw length, body depth 1, body depth 2, body width, caudal peduncle depth, upper peduncle length, pectoral-fin length, pelvic-fin length, dorsal-fin base length, spinous dorsal-fin base length, soft dorsal-fin base length, preanal length, predorsal
length, prepelvic length, pelvic-to-anal-fin length, 2nd dorsal-fin spine length, 3rd dorsal-fin spine length, and gill taker length.