Taxonomy & naming
Hypostomus caudofasciatus was formally described by Zawadzki and Azevedo in 2024 in Zootaxa (volume 5471, number 3, pages 318–328). The type locality is the Rio Sapucaí-Mirim, a tributary of Rio Grande in the municipality of Guará, São Paulo State, Brazil (coordinates approximately −20.497°S, −47.864°W). No synonyms have been recorded. The Catalog of Fishes (Eschmeyer, CAS) registers the species under genus id 553, species id 77754.
The valid name Hypostomus caudofasciatus Zawadzki & Azevedo, 2024 is unambiguous and carries no preceding combination; this is an original description with no earlier usage of the epithet for this taxon. The placement within Hypostomus (Lacépède, 1803) follows the authors' assessment of morphological affinities within the genus.
At the time of writing, the species has not been assigned to a named species group within the large and heterogeneous genus Hypostomus, nor has it received an L-number or any ornamental trade designation. As a 2024 description, it is expected to be absent from older reference works.
Morphology
The maximum recorded length is 6.5 in standard length (SL), based on specimens examined in the original description (Zawadzki & Azevedo 2024, reference 133475 on FishBase). The body is elongated and dorsoventrally flattened in the typical Hypostomus bauplan, encased in rows of overlapping bony scutes.
The species is distinguished by a striking colour pattern: the caudal fin bears longitudinal dark stripes on a yellow background, a combination not previously described in the genus and directly referenced by the species name. The lateral series of plates carry horizontally aligned stripes. The ventrolateral caudal peduncle and proximal regions of the anal and caudal fins appear to lack strong patterning, providing contrast with the distal fin coloration.
Diagnostic meristic and morphometric features include: upper-jaw teeth 21–39; straight dentary tooth rows; orbital diameter 20.7–25.0% of head length; 2 dorsal spines and 7 dorsal soft rays; 4 anal soft rays; keels absent on the lateral series of plates. The tooth count and straight dentary configuration place it among the more grazing-oriented Hypostomus rather than the spoon-toothed wood-eating forms.
Habitat
The type locality and known distribution centre on the Rio Sapucaí-Mirim and the broader upper Rio Paraná basin in São Paulo State, Brazil. The river systems involved — Rio Grande (a major Paraná tributary) and its smaller feeder streams — are part of the La Plata drainage, the second largest river system in South America.
Field data from the original description characterise the habitat as small to medium-sized streams, 1–16 ft deep, with substrates of sand, clay, loose gravel, and occasionally pebbles and boulders. This is a shallow stream environment typical of the Brazilian cerrado / Atlantic forest transition zone, where upper Paraná tributaries often run over unconsolidated sediments with variable organic matter input.
No water chemistry parameters (temperature, pH, conductivity) are available in the sources reviewed. The upper Paraná basin encompasses substantial environmental diversity, and without field measurements from the specific collection sites, parameter ranges for the natural habitat cannot be provided.
Feeding
No feeding data specific to H. caudofasciatus have been published. The straight dentary tooth rows and moderate tooth counts (21–39 upper-jaw teeth) are consistent with the broadly algivorous and detritivorous feeding strategy typical of the majority of Hypostomus species. These fish rasp algal films, biofilm, and fine organic detritus from substrates using the ventral suckermouth, moving methodically across rock, wood, and gravel surfaces.
The absence of spoon-shaped teeth and the lack of any reference to xylophage behaviour in the original description suggest this species is not a wood specialist. Beyond these general inferences from morphology, no diet-specific data are available.
Data sparse.
Mating
No mating observations for H. caudofasciatus have been reported from the wild or in captivity. The species was described in 2024 and has not entered the aquarium trade at any documented level; no hobbyist breeding accounts exist. Courtship and pair behaviour are entirely undocumented.
Data sparse.
Breeding
No breeding records exist for H. caudofasciatus. The species is too newly described to have accumulated any aquarium breeding reports, and no field observations of reproductive behaviour appear in the original description or subsequent literature.
Data sparse.
In the aquarium
Hypostomus caudofasciatus has not been documented in the ornamental fish trade. It carries no common name, no L-number, and no husbandry records appear in accessible hobbyist databases as of mid-2024. PlanetCatfish records the species as very new, with hobbyist data entirely absent.
The species' striking caudal fin coloration — yellow with longitudinal dark stripes — would likely make it attractive to hobbyists if it becomes available. At adult sizes of up to ~6.5 in SL, it would require a tank of at least 55 US gal with appropriate filtration for an algivorous Hypostomus. General husbandry applicable to medium-sized Hypostomus would be a reasonable baseline — clean, well-oxygenated water, algae wafers and blanched vegetables, smooth rocks or driftwood for rasping — but no species-specific guidance can be offered until husbandry experience accumulates.
Conservation
Hypostomus caudofasciatus has not been evaluated by the IUCN Red List. Described only in 2024, it falls outside the assessment cycle for recently named species, and no population data, range modelling, or threat assessment has been conducted.
The upper Rio Paraná basin in São Paulo State is one of Brazil's most heavily modified river landscapes, subject to agricultural intensification, urban expansion, water extraction, and regulation by large hydroelectric impoundments. Whether H. caudofasciatus is narrowly endemic to the Rio Sapucaí-Mirim catchment or more broadly distributed through upper Paraná tributaries is not yet established. Its conservation status remains formally Not Evaluated.