Taxonomy & naming
Tometes makue was described in 2002 by Jégu, Santos and Belmont-Jégu, part of a wave of taxonomic work in the early 2000s that clarified the genus Tometes within the family Serrasalmidae — the piranhas, pacus and silver dollars of Characiformes. Serrasalmidae has been extensively revised over the past two decades, with silver-dollar-type species redistributed out of the old catch-all genus Myleus into narrower genera including Myloplus, Ossubtus and Tometes; older literature or trade listings that use "Myleus" for this fish reflect that pre-revision classification rather than the currently accepted name. The Catalog of Fishes (Eschmeyer, California Academy of Sciences) is the standing authority for the valid combination Tometes makue, and this article keeps that genus assignment throughout.
The species epithet "makue" is not explained in the sources consulted for this article; rather than guess at an etymology, this account leaves it undocumented pending a source that states the authors' intent. Tometes makue has no established English common name in the aquarium trade — it circulates, when it appears at all, simply as a Tometes or under the generic "silver dollar" label, sometimes conflated with the more commonly traded Myloplus and Metynnis species that share the same body plan.
Morphology
Like other Tometes and Myloplus species, T. makue has the classic silver-dollar build: a strongly compressed, disc-shaped body that is nearly as tall as it is long, giving the fish a coin-like silhouette when viewed head-on or from the side. FishBase records a maximum published size of 15 in standard length, which is large for a silver-dollar-type serrasalmid and makes this one of the bigger-bodied members of the group — closer in scale to a small pacu than to the compact, hand-sized Metynnis species commonly sold as "silver dollars" in the trade.
FishBase's morphological data for the species lists 20–24 dorsal soft rays, 30–36 anal soft rays and 39–40 vertebrae, along with a small number of prepelvic serrae (0–9) and total serrae (10–23) along the ventral keel — the saw-edged belly scutes characteristic of the family, though reduced compared to the true piranhas. An aquarium-import account from Aquarium Glaser describes a total length of roughly 15.5 in in a captive specimen, corroborating the FishBase figure and confirming this as a genuinely large aquarium fish at maturity, not a permanently small one.
Habitat
Tometes makue is native to the middle and upper Negro River and the Orinoco River basin in South America, placing it among the blackwater and clearwater systems of the northern Amazon and the Orinoco drainage rather than the whitewater, sediment-rich rivers found elsewhere in the basin. FishBase classifies it as a pelagic, tropical freshwater species, consistent with an open-water grazer that moves through the water column over submerged vegetation and flooded structure rather than holding tight to the bottom.
Detailed water-chemistry data specific to this species was not found in the sources consulted; the Negro River system in particular is known more broadly for soft, acidic, tannin-stained blackwater conditions, but this article does not assert specific pH or hardness figures for T. makue beyond what is documented, since generalising from the wider Negro basin to a single species risks overstating precision the sources do not support.
Feeding
Tometes, along with its close relatives Myloplus and Ossubtus, are grazing herbivores within Serrasalmidae, feeding on aquatic vegetation, algae and, seasonally, on fallen fruit and seeds from the flooded forest margin — the same general dietary pattern documented across the silver-dollar lineage. Sources specific to T. makue do not provide detailed stomach-content data, but its build and its placement among the herbivorous Tometes species make a plant- and algae-based diet the well-supported expectation, and aquarium accounts of the species as an aggressive plant-shredder in captivity are consistent with that.
In the aquarium, keepers should offer a vegetable-forward diet — blanched vegetables such as courgette, cucumber and spinach, spirulina-based flake or pellet, and algae wafers — supplemented with only modest protein. A silver dollar kept on a protein-heavy diet intended for predatory fish is being fed against its biology; the fish's natural grazing habit means it will happily substitute a planted tank's soft growth for the vegetable matter it isn't offered.
Mating
No courtship or pair-formation behaviour specific to Tometes makue was found in the sources consulted for this article, and none of the cached material documents sexual dimorphism in the species. Data is sparse enough here that this article does not speculate about courtship displays, colour changes or size differences between the sexes — nothing in FishBase, the aquarium-import notes or the conservation screening documents addresses reproductive behaviour or external sex differences for this species.
Breeding
Tometes makue has not been documented as bred in the aquarium hobby in any source consulted for this article. Its relatives among the silver dollars (Metynnis, Myloplus) are broadly understood as egg-scatterers that release adhesive eggs over fine-leaved plants with no parental care, and — absent species-specific data to the contrary — that is the general pattern this fish most plausibly follows. But this article does not assert a confirmed breeding account for T. makue itself; it should be treated as a species essentially unbred in captivity, reflecting both its large adult size and its narrow, specialist collection range in the wild.
In the aquarium
Tometes makue is a large silver dollar — a published maximum of 15 in SL, corroborated by an aquarium specimen reported at roughly 15.5 in total length — and it needs to be sized accordingly: a tank suited to a small pacu rather than to the compact Metynnis species usually sold under the "silver dollar" name. An aquarium-import account from Aquarium Glaser specifically describes the species as quarrelsome toward conspecifics and incompatible with other serrasalmids sharing the tank, including Myleus schomburgkii, and otherwise as a hardy, undemanding fish once acclimated. That combination — robust health but a short temper toward its own family — argues for a spacious tank with clear sightlines broken by driftwood or rockwork rather than a densely aquascaped layout.
The single most important care note is dietary: as a grazing herbivore, T. makue will shred soft-leaved aquarium plants with the same enthusiasm it shows for algae and vegetation in the wild, so a planted tank is the wrong environment for this fish unless the keeper accepts the plants as a renewable food source rather than permanent decor. Robust, tough-leaved or artificial hardscape, combined with a vegetable-forward feeding routine, suits the species far better than a soft aquascape.
Conservation
The IUCN Red List assesses Tometes makue as Least Concern, an assessment reflected in FishBase's summary and dated to December 22, 2020, with high resilience and a minimum population doubling time of under 15 months. This status is consistent with a species occupying a still relatively intact stretch of the middle and upper Negro and Orinoco basins without documented major population pressure.
The species was also profiled in a US Fish & Wildlife Service Ecological Risk Screening Summary, a document produced to assess the risk this fish would pose if introduced outside its native range — standard due diligence for species that enter the aquarium trade, rather than an indicator of conservation concern within its native waters. No wild-collection pressure specific to T. makue is documented in the sources consulted; it does not appear to be a heavily trafficked aquarium species, and its conservation picture is best summarised as stable but sparsely studied.