Taxonomy & naming
Hyphessobrycon chocoensis was formally described by Carlos A. García-Alzate, César Román-Valencia, and Donald C. Taphorn in 2013, in a paper published in the Revista de Biología Tropical (volume 61, issue 1). The type locality is Quebrada de la Tundera, a tributary of the Quigualpí River in the Telembí River basin, Nariño Department, Colombia, at approximately 148 ft elevation. Eschmeyer's Catalog of Fishes (CAS) records the name as valid with no synonyms.
The species belongs to the large, heterogeneous genus Hyphessobrycon, which encompasses hundreds of small characid tetras distributed across Central and South America. Within that genus, H. chocoensis is considered most closely related to other Pacific-slope Colombian characids including Hyphessobrycon daguae, to which it was compared in the original description. Its meristic formula includes 10 dorsal soft rays and 33 vertebrae, falling within the typical range for the genus.
Morphology
Hyphessobrycon chocoensis is a small tetra reaching a maximum recorded standard length of 1.5 in. Like other members of the genus it is laterally compressed, with a moderately deep body, a terminal mouth, and the characteristic adipose fin of the Characidae.
The species is diagnosed principally by a combination of absence characters: it lacks the dark spot on the dorsal fin and the spot or band on the caudal peduncle that mark several related species, and instead bears a diffuse humeral spot — a pale to dusky blotch behind the opercle on the shoulder region. Body coloration details beyond these diagnostic marks are not fully documented in available sources, and the overall patterning is likely subdued, as is typical for many cryptic small Hyphessobrycon from Pacific-slope Colombian drainages.
Habitat
The species is known from creek and wetland habitat in the Telembí River drainage of the Southern Pacific slope of Colombia, with the type locality being Quebrada de la Tundera, a small tributary of the Quigualpí River in Nariño Department. The collection site lies at roughly 148 ft above sea level, in the lowland Chocó biogeographic region, one of the most biodiverse and rainfall-heavy areas in the world.
FishBase classifies H. chocoensis as benthopelagic and tropical freshwater. The IUCN assessment records its known extent of occurrence as approximately 217 mi², confined to the Telembí basin in Nariño Department. Beyond the known collection points in the Quebrada de la Tundera and the broader Telembí drainage, the full habitat range of the species has not been systematically surveyed, and water chemistry parameters for the type locality are not reported in currently available sources.
Feeding
No specific dietary studies of Hyphessobrycon chocoensis have been published. Based on the general biology of the genus and its benthopelagic freshwater habits, the species is presumed to be an opportunistic omnivore feeding on small aquatic invertebrates, insect larvae, microcrustaceans, and organic detritus in its lowland creek and wetland habitat.
In the aquarium, congeners of similar size and ecology typically accept a wide range of small prepared and live foods, including fine flake, micro-pellets, and frozen items such as Daphnia, brine shrimp nauplii, and Cyclops. Data on the specific feeding behaviour and diet of wild H. chocoensis remain sparse.
Mating
No observations of mating behaviour in Hyphessobrycon chocoensis have been recorded. The species has not been documented in the aquarium hobby, and field behavioural data are absent from available sources.
As with other small Hyphessobrycon, egg-scattering open spawning among fine-leaved vegetation with no parental care is the expected reproductive mode, based on the reproductive biology of the genus as a whole. Sexual dimorphism, if present, has not been described for this species.
Breeding
Breeding has not been documented for Hyphessobrycon chocoensis in captivity or in detail in the wild. In the broader genus, breeding typically involves scattering small, adhesive eggs among fine-leaved aquatic plants or substrate debris, after which adults provide no parental care and may consume the eggs.
Given the species' limited presence in the hobby and sparse documentation overall, husbandry and captive breeding protocols specific to H. chocoensis are not available. Researchers and aquarists with access to the species would likely follow protocols used for similarly sized, closely related Pacific-slope Hyphessobrycon such as H. daguae.
In the aquarium
Hyphessobrycon chocoensis has not been established in the ornamental fish trade and is essentially unknown in the hobby. No specimens are known to be in circulation, and no aquarium husbandry guidelines specific to the species have been published.
By analogy with similar small Hyphessobrycon from Colombian Pacific drainages, it would presumably do best in a species tank or community of small, peaceful fish with warm soft to moderately hard, slightly acidic to neutral water, fine-leaved planting, and subdued lighting. Until further field collection and population assessment occur, the species is unlikely to enter hobbyist availability.
Conservation
Hyphessobrycon chocoensis is assessed as Data Deficient (DD) on the IUCN Red List, with the assessment dated 9 October 2014 and published in 2016. The assessor, F. Villa-Navarro, noted that the species is endemic to Colombia and known only from the Quebrada de la Tundera type locality and the broader Telembí River basin in Nariño Department, with an extent of occurrence of just 217 mi². Population size and trend are unknown, and no population data were available at the time of assessment.
Potential threats were not characterised beyond a general note that the species may be affected by deforestation in the Chocó region, one of the most heavily deforested tropical zones in the Americas. The species does not occur in any protected area, and it is not listed under CITES. The Data Deficient status reflects lack of knowledge rather than confirmed stability; the Chocó's ongoing deforestation and land conversion represent a plausible but unquantified risk to this narrowly endemic species.