Taxonomy & naming
Otothyropsis alicula was described by Lippert, Calegari and Reis in 2014 in Copeia (2014, number 2, pages 238–244), in a paper announcing a new species of Otothyropsis from eastern Brazil. The Catalog of Fishes (Eschmeyer, CAS) recognises the species as valid.
The genus Otothyropsis belongs to the subfamily Hypoptopomatinae, the small armoured catfishes known in Brazil as cascudinhos. The species is diagnosed by a unique caudal-fin pattern — a densely pigmented blotch on the proximal half of the fin prolonged onto the middle rays — together with a short pectoral-fin spine (16.5–20.0% of standard length) and a rectangular dorsal-fin spinelet.
Morphology
Otothyropsis alicula reaches about 1.5 in standard length. It has the elongate, dorsally flattened, plate-armoured body typical of Hypoptopomatinae, with a ventral suckermouth. Fin counts are dorsal ii,7 and anal i,5, with 29–30 vertebrae.
The most distinctive features are the caudal-fin blotch noted above, the short pectoral-fin spine, and a rectangular (rather than triangular) dorsal-fin spinelet. No information on sexual dimorphism has been published for this species.
Habitat
Otothyropsis alicula is known from the Rio Santo Antônio basin, a tributary of the Rio Sapucaí within the upper Rio Grande, which drains to the upper Rio Paraná system, in Minas Gerais, southeastern Brazil. The environment is freshwater, demersal and tropical. No published water-chemistry measurements (temperature, pH, hardness) are available for the locality.
Feeding
No direct diet study has been published for Otothyropsis alicula. Its trophic level is estimated at about 2.3 from a model, consistent with the herbivore/detritivore habit typical of the genus — grazing biofilm, algae and fine detritus from submerged surfaces.
Mating
No data on courtship or mating behaviour have been published for this species.
Breeding
No breeding data have been published for Otothyropsis alicula. The species is not known to have been bred in aquaria.
In the aquarium
Husbandry data for Otothyropsis alicula are sparse; the species is not established in the ornamental trade and no documented aquarium experience exists. As a small grazing cascudinho from a tropical stream system, it would in principle need clean, oxygenated water and grazing surfaces, but specific care recommendations would be speculative.
Conservation
The IUCN Red List assessed Otothyropsis alicula as Least Concern in 2018. The species is not currently considered threatened, though as a small fish with a restricted known range it depends on the continued integrity of its upper Rio Grande tributary habitats.