The
holotype specimen of
N. pnar is long, & the largest individual sighted in its natural cave habitat exceeded in
standard length, making this species the largest known subterranean fish. The head of this fish is large, accounting for a bit over a quarter of its length, and has two pairs of
barbels. All fins of
N. pnar are
hyaline and translucent. This species is white or pinkish in color, with no pigmentation from
melanophores. The eye size in this species reduces as overall body size increases: in the largest individuals they cannot be discerned without very close inspection, whilst the eyes of smaller juveniles are clearly visible large dark spots under the skin surface.
N. pnar has a continuous
lateral lines with 28–31 perforated
scales, as well as an additional 1–2 on the
caudal fin base. ==Ecology and habitat==