Taxonomy & naming
Poptella magnuspina was described by Garcia-Ayala, Oliveira and Benine in 2025, making it among the most recently erected species in the genus. The valid name as governed by Eschmeyer's Catalog of Fishes is Poptella magnuspina Garcia-Ayala, Oliveira & Benine, 2025. The original description was published in a Brazilian ichthyological journal — the authors are associated with Neotropical fish systematics, with a publishing record in journals such as Neotropical Ichthyology.
The genus Poptella Eigenmann, 1908 belongs to the family Characidae, the largest family of freshwater fishes in the New World. Poptella species are small to medium-sized characids characterised by a strongly compressed, deep body, large eyes, and a silvery coloration often with a dark lateral stripe or humeral spot. The genus has historically been placed in various subfamilial arrangements as the internal phylogeny of Characidae has been revised; current treatment places it within Characidae without a firmly resolved subfamily assignment. Several species in the genus are wide-ranging across multiple South American drainages, while others are more locally distributed.
Morphology
Poptella magnuspina reaches approximately 2 in total length based on data recorded in FishBase. Like other members of the genus, it is a laterally compressed, deep-bodied fish with a roughly rhomboidal body profile, large eyes, and a terminal mouth. The general coloration is silvery, as is typical of Poptella, with details of pigmentation and body proportions that distinguish it from congeners.
The specific epithet magnuspina — from Latin magnus (large) and spina (spine or thorn) — signals that a prominently developed spine or spinous structure is a diagnostic character of the species, distinguishing it from related Poptella. The precise meristic and morphometric data establishing its limits relative to congeners are detailed in the original 2025 description. As with most freshwater characids, the adipose fin is present, and the lateral line is complete.
Habitat
Poptella magnuspina is distributed in South America, as is the entire genus. The broader Poptella genus occupies a wide range of lowland freshwater environments across the Amazon, Orinoco, Paraguay, and other major South American drainages, typically inhabiting open water over sandy or muddy substrates in rivers, flooded plains, and associated lagoons and streams.
Specific collecting locality data for P. magnuspina is in the original 2025 description. Given the genus's general ecology, the species likely occupies flowing or standing freshwater with warm, soft to moderately hard conditions typical of lowland tropical South America. Data on its precise drainage distribution and habitat preferences were sparse at the time of writing.
Feeding
No published dietary study exists specifically for Poptella magnuspina. Members of Poptella are generally considered small-prey omnivores or micropredators, taking small invertebrates, zooplankton, and plant material, consistent with the generalist feeding habits widespread in Characidae.
In an aquarium setting, close relatives of similar size accept a range of small prepared foods, live and frozen invertebrates such as Daphnia, brine shrimp, and micro-worms, and finely crushed flake. A varied diet is recommended to maintain condition. Details specific to P. magnuspina should be treated as inferred from congeners until more is known.
Mating
No direct observations of mating behaviour in Poptella magnuspina have been published. Characids of this body plan are typically egg-scattering open spawners with no parental care. In the wild, spawning is often associated with the rainy season and rising water levels, which trigger reproductive activity across many Neotropical characids.
Males in related species may display subtle lateral colour intensification and compete for proximity to receptive females. Spawning takes place in open water or over fine-leaved vegetation, with adhesive or semi-adhesive eggs deposited among plants. These details are inferred from the genus and family; specific observations for P. magnuspina are not yet available in the literature.
Breeding
Breeding details specific to Poptella magnuspina are not yet documented in the hobby or scientific literature as of 2025. Based on family-level biology, the species is expected to be an egg-scattering spawner that deposits adhesive eggs among fine-leaved aquatic vegetation or over the substrate, with no parental care by either parent.
In aquarium conditions, congeners and morphologically similar small characids are typically bred by conditioning adults on live and frozen foods, allowing spawning over spawning mops or fine-leaved plants, and removing adults promptly after spawning to prevent egg predation. Fry are very small at hatching and require infusoria or comparable first foods before graduating to larger live prey. Specific breeding accounts for P. magnuspina remain to be reported.
In the aquarium
Poptella magnuspina has not yet established a presence in the mainstream aquarium hobby as of its 2025 description, and dedicated husbandry guides do not exist. Given the general requirements of the genus and comparable small South American characids, the species would be expected to do well in a moderately sized aquarium with soft to moderately hard, slightly acidic to neutral water at temperatures in the range typical of lowland tropical South America, around 75–82 °F.
Small characids of this type are generally peaceful schooling fish best kept in groups of six or more, with open swimming space and some planted areas for cover. They are unlikely to bother tankmates of similar or larger size. Until dedicated husbandry experience accumulates in the hobby, care guidance should be drawn from well-documented congeners.
Conservation
Poptella magnuspina has not been assessed by the IUCN Red List as of 2025 — the species was described that year and formal assessments typically follow years after a formal description. It is accordingly treated as Not Evaluated (NE). No information on population size, range trends, or specific threats is yet available for this species.
The broader genus Poptella includes species that are locally common across large South American drainages and are not currently considered threatened. Whether P. magnuspina has a broad or restricted range, and what pressures it may face, will depend on the locality data provided in the original description and on subsequent field surveys.