Taxonomy & naming
Curimata macrops was described by Carl H. Eigenmann and Rosa Smith Eigenmann in 1889. It belongs to the genus Curimata within the family Curimatidae, a distinct lineage of toothless, detritus-feeding characins placed in the order Characiformes alongside the piranhas, pacus and silver dollars of Serrasalmidae covered elsewhere in this atlas — the two families share the order but not the jaws, teeth or diet that make the "piranha" name relevant. ITIS (Taxonomic Serial Number 640881) confirms Eigenmann & Eigenmann, 1889 as the valid authority and combination for this species.
Curimata is a modestly sized genus of South American toothless characins, and species-level identification within it rests on fine anatomical detail — proportions of the head, fin-ray counts and scale counts — rather than any obvious external field mark, which is typical of the family and is part of why these fish stay obscure outside specialist taxonomic work.
Morphology
Curimata macrops is a small, laterally compressed, silvery characin with the toothless, downturned mouth typical of Curimatidae — an adaptation for grazing and sifting rather than biting or grasping prey. FishBase records a maximum size of 7.5 in standard length, a genuinely modest adult size, well short of the pacus and larger characins covered elsewhere in this family group.
Like its relatives in the family, it lacks jaw teeth altogether, relying instead on pharyngeal structures to process the fine organic and algal material it grazes from surfaces and sediment. Detailed colouration and fin-shape description are not available from the cached sources for this species specifically; the wider genus and family are generally plain silver fish without strong pattern, consistent with an animal that spends its life grazing river bottoms rather than displaying.
Habitat
The species is known from the Poti and Parnaíba river system of northeastern Brazil, placing it among the smaller number of Curimatidae restricted to that basin rather than the wider Amazon or Paraguay-Paraná drainages that carry many of this atlas's other characins. Within Curimatidae generally, species occupy the flowing to gently flowing channels of tropical South American rivers, from southern Costa Rica to northern Argentina across the family as a whole, grazing algae, zooplankton and detritus from the periphyton film on rocks, wood and sediment.
Specific water chemistry data for Curimata macrops itself is not available from the cached sources; the family more broadly is associated with warm water in roughly the 73–81 °F range and pH 6.0–7.8, and with habitats that provide current plus cover from rocks or submerged wood — consistent with a grazing fish that needs both flow, for oxygen and food delivery, and structure to retreat into.
Feeding
Curimata macrops is a detritivore/grazer, the default diet for its toothless family. Curimatidae lack jaw teeth entirely and instead browse periphyton — the algae, biofilm, associated microfauna and organic detritus that coats submerged rocks, wood and sediment — rather than pursuing live prey or plant matter in the way many other characins do. A study of the congener Curimata mivartii documented detritivorous feeding on organic debris and benthic organisms, and the same general feeding mode is the reasonable expectation for C. macrops, though species-specific dietary data was not found in the cache.
This toothless, grazing diet distinguishes the Curimatidae sharply from the predatory Serrasalmidae members of this atlas's piranha and pacu groups, and it is worth stating plainly: this is not a fish built to bite anything, and its ecological role in its home rivers is closer to a bottom-cleaning grazer than to a predator or even an omnivore in the usual sense.
Mating
No courtship or spawning-behaviour data for Curimata macrops was found in the cached sources, and none is claimed here. The species has no established aquarium-breeding history to draw on, and the cached literature (FishBase, IUCN, ITIS, and a congener study on feeding ecology) does not address reproductive behaviour.
Breeding
Breeding biology for Curimata macrops specifically is not documented in the cached sources, and this account does not guess at a mode. The species is not part of the aquarium trade and has no record of home or commercial breeding; as with several other minor, single-basin characins in this atlas, honest treatment here means stating that the data is sparse rather than assigning a spawning strategy from memory or by analogy to unrelated groups.
In the aquarium
Curimata macrops has essentially no presence in the aquarium hobby — it carries no established common name and does not appear in the trade literature consulted for this account. General care notes for the toothless Curimatidae as a family suggest a need for current and hiding places (rocks or driftwood) plus warm water around 73–81 °F and pH 6.0–7.8, but these are family-level generalisations rather than species-specific guidance, and a prospective keeper should treat them as a starting point only, not a confirmed care sheet for this species.
Given its modest adult size of about 7.5 in and grazing, detritivorous habits, a fish of this kind would in principle suit a river-style setup with flow and biofilm-covered surfaces rather than the large predator or shoaling-piranha tanks discussed elsewhere in this family group — but since it is not a documented aquarium fish, this remains a reasonable inference rather than tested advice.
Conservation
The IUCN Red List assesses Curimata macrops as Least Concern, an assessment dated 7 November 2018, reflecting FishBase's characterisation of the species as having medium resilience (a population doubling time of 1.4–4.4 years) and low vulnerability to fishing pressure. This is consistent with a small-bodied grazing species that is not itself a fisheries target and faces no documented specific threat within its Poti-Parnaíba range.
As with many single-basin, non-commercial characins, the main long-term watch items are the general pressures on northeastern Brazilian river systems — water abstraction, damming and land-use change — rather than any threat specific to this species; none of these is flagged as an active concern in the current assessment.