''Exastilithoxus'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of suckermouth armored catfish native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

Species

There are currently two recognized species in this genus: * '' Exastilithoxus fimbriatus'' ( Steindachner, 1915) * '' Exastilithoxus hoedemani'' Isbrücker & Nijssen, 1985

Appearance and anatomy

''Exastilithoxus'' species are small, cylindrical loricariids. These species exhibit a round lower lip with fleshy

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...

. Color pattern is generally mottled and dark brown with paler areas under and just posterior to the dorsal fin. The abdomen is white, fins are mottled, and the ventral surface of the

caudal peduncle Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

is colored as the sides, but slightly lighter. Like other loricariids, the body is armored, however the abdomen is naked.

Ecology

''Exastilithoxus'' species are unique among loricariids in that they subsist entirely on

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

References

Ancistrini Fish of South America Catfish genera Taxa named by Isaäc J. H. Isbrücker Taxa named by Han Nijssen Freshwater fish genera {{Loricariidae-stub