Table 1. Morphometric data of holotype and paratypes of Trichomycterus payaya (n = 15). The ranges include the holotype. SD = Standard deviation.
Holotype Range Mean SD
Standard length (mm) 37.4 29.2-37.4 32.7 -
Total length (mm) 43.7 33.0-43.7 38.0 -
Percents of Standard length
Body depth 13.9 13.2-16.3 14.4 1.12
Body width 10.7 10.0-14.0 11.6 1.21
Caudal peduncle depth 9.1 7.5-10.2 8.8 0.79
Caudal peduncle length 19.5 17.4-22.2 19.7 1.18
Predorsal length 67.6 64.9-68.5 66.9 1.11
Preanal length 69.3 66.8-71.8 68.8 1.39
Prepelvic length 58.3 53.5-58.3 54.8 1.81
Dorsal-fin base length 9.9 9.9-12.9 11.4 0.85
Anal-fin base length 8.3 7.8-10.7 9.2 0.88
Dorsal-caudal length 12.1 7.6-12.5 10.3 1.53
Nasal barbel length 14.2 12.9-15.9 14.8 0.93
Maxillary barbel length 16.6 13.8-19.1 16.3 1.26
Rictal barbel length 13.1 12.6-15.8 13.7 0.91
Head length 20.3 19.7-22.4 21.1 0.81
Percents of Head length
Head width 81.6 78.1-82.9 80.8 1.44
Head depth 42.1 37.0-43.1 40.1 1.85
Inteorbital distance 25.0 25.0-29.3 27.3 1.52
Internarial distance 15.8 11.9-15.8 14.4 1.25
Internarial width 21.4 21.1-27.3 24.3 2.01
Snout length 35.5 32.8-38.8 35.8 1.74
Orbital diameter 11.8 9.6-12.3 11.2 0.84
Mouth width 36.8 35.6-40.9 38.4 1.50