Distinguished from T.
quadrifilis in the alignment of the lateral margins of the
head in the region from the anterior margin of the orbit to the
posterior limit of the opercle (running approximately in parallel
from ventral view vs. diverging laterally, respectively); in the
body width at the pectoral-fin insertion as a proportion of the
head width at the posterior margin of the orbit (0.99-1.10 vs. 1.17-1.25,
respectively); in the distance from the tip of the snout to the
anal fin origin (0.29-0.32 of SL vs. 0.33-0.36 of SL, respectively);
and in the position of the anterior termination of the gill opening
(one orbital diameter posterior of the transverse plane running
through the posterior margin of the orbit vs. positioned in the
transverse plane running through the center of the orbit, respectively).
America : Amazon basin: upper Negro River system in Brazil
and Venezuela and upper Orinoco River basin in southern Venezuela.
Vari, R.P. and
C. Ferraris, Jr. 2006 The catfish genus Tetranematichthys
(Aucheniptridae). Copeia 2006(2):168-180.