Inhabits streams with rocky and sandy bottom; in shallow
and deeper (up to 0.7 m) areas with water flow up
to 70 cm per second. Forages at night, although occasional
diurnal activity is also recorded. Before grazing
on a patch with dense sediment, the fish makes wiggling
head-down movements, which raise sediment and blown
away by the water current. Density may reach about
0.1 fish per square meter both in shaded and sunned
stream stretches. Aquarium Care:
Not the easiest genera to keep as they will need clean,
oxygen rich water and a strong current. They will
also need reduced temperatures in the aquarium due
to their southern habitats. Does not do well in imports
due to its difficulty in traveling containers. Sexual
Differences: Males tend to have odontodes
(hair like structures) on the first ray of the pectoral
fins and the head in males is broader. Diet:
Grazes on microscopic algae, mostly diatoms and green
algae growing on rugged and light-coloured rocks,
and submersed vegetation. Chironomid and simuliid
larvae, as well as tiny crustaceans, are recorded
in its diet. When scraping algae off the substrate,
the fish makes vigorous mouth movements and jerky
movements, probably related to its mouth making alternate
grazing and attaching to the substrate. In the aquarium
feed dry foods, algae wafers, Spirulina and normal
tablet foods. Frozen foods, Artemia nauplii,
glass worms and Daphnia.
South America:Ribeira de Iguapé River basin, Brazil.
Type locality: Rio Bethary, Brazil.
H.-G. & I.Seidel: Mergus, Baensch Catfish
Atlas Volume 1, 1st English edn., 2005. Pp.944. Froese, R. and D. Pauly. Editors. 2011.
FishBase. World Wide Web electronic publication. www.fishbase.org,
version. Ferraris, C.J. Jr., 2007. Checklist
of catfishes, recent and fossil (Osteichthyes: Siluriformes),
and catalogue of siluriform primary types. Zootaxa 1418:1-628.
Buck, S. and I. Sazima, 1995. An assemblage
of mailed catfishes (Loricariidae) in southeastern Brazil:
distribution, activity and feeding. Ichthyol. Explor.