Morphology Data of Psilorhynchus melissa
Identification keys
Main Ref. Conway, K.W. and M. Kottelat, 2010
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral elongated
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth sub-terminal/inferior
Type of scales

Shares with its most similar species Psilorhynchus robustus and Psilorhynchus gracilis a dark reticulate pattern over the dorsal and lateral surfaces of the body. Differs from Psilorhynchus robustus and all its congeners by the presence (vs. absence) of a dark band running along the distal edge of the dorsal fin and by the presence of intense (vs. light) scattering of dark melanophores along the anterior edge of the paired fins. Can be further distinguished from Psilorhynchus robustus by its longer, narrower head (head length 22-26% SL vs. 20-22, head width 62-65% HL vs. 67-73), and narrower mouth (mouth width 24-28% HL vs. 28-31), from all other species of the genus, except Psilorhynchus robustus

and Psilorhynchus gracilis, by the presence (vs. absence) of a dark reticulate pattern

over the dorsal and lateral surfaces of the body, and from all other species of the genus, excluding Psilorhynchus robustus, by the presence (vs. absence) of an indistinct lateral streak, formed by a series of small dark spots between the pores of the lateral line canal. Furthermore, can be readily diagnosed from two other congeners (Psilorhynchus breviminor and Psilorhynchus pavimentatus) from Myanmar by having shallower caudal peduncle 7-8 % SL (vs. 9-10 in both Psilorhynchus breviminorand Psilorhynchus pavimentatus), and from Psilorhynchus pavimentatus by having 10 principal rays in the upper caudal fin lobe 10 (vs. 9) (Ref. 85100).

Description: Dorsal fin with iii.9 rays; anal fin with ii.6 rays; pectoral with fin v.11 rays; pelvic fin with ii.7 rays (Ref. 85100).

Ease of Identification

Meristic characteristics of Psilorhynchus melissa

Lateral Lines Interrupted: No
Scales on lateral line 32 - 34
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle 10 - 10
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
preanal 18 - 18
total 34 - 34


Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Spines total
Soft-rays total 12 - 12
Adipose fin absent

Caudal fin

Attributes forked

Anal fin(s)

Fins number
Spines total
Soft-rays total 8 - 8

Paired fins

Pectoral Attributes  more or less normal
Soft-rays   16 - 16
Pelvics Attributes  more or less normal
Position    abdominal  behind origin of D1
Soft-rays   9 - 9
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Torres, Armi G.
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cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17