Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Characidae
(Characins) > Tetragonopterinae
Etymology: Tetragonopterus: Greek, tetra = four + Greek, gonia = angle + Greek, pteron = wing, fin (Ref. 45335); akamai: Named for Alberto Akama in recognition of his contributions to Neotropical ichthyology and in recognition of his many collecting efforts on several South American drainages. A noun in apposition.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Upper and middle portions of the rio Tocantins drainage, Brazil.
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 5 - ? cm
Max length : 6.1 cm SL male/unsexed; (Ref. 96868)
Morphology | Morphometrics
Vertebrae: 30 - 33. Tetragonopterus akamai is distinguished from all its congeners by having a unique shape of the maxilla: anterodorsal portion of the maxilla that is articulated with the premaxilla is bent over, in close contact with the dorsal surface of the premaxilla and very short (about 5.5-5.9% of length of the free portion of the maxilla); the anterodorsal border of the proximal portion of the maxilla articulated with the premaxilla is concave and angled approximately 90 degrees relative to the free portion of the maxilla; the tip of the anterodorsal portion of the maxilla that is articulated with the premaxilla does not reach the vertical through the anterior margin of the antepenultimate teeth of the inner premaxillary series. It further differs from T. argenteus, T. chalceus, T. denticulatus, T. araguaiensis, T. rarus, and T. carvalhoi by having superior mouth (vs. terminal). It can be distinguished from T. anostomus by having longer snout 20.0-27.6% (vs. 9.5-14.3% HL) and by its relative size of the teeth on the inner premaxillary series, which are much larger than those of the outer series (vs. teeth of the inner premaxillary series as large as or smaller than those of the outer series in T. anostomus); from T. anostomus by having 9-10/14-16 gill rakers on the first branchial arch (vs. 11/18); from T. rarus by the absence of dark longitudinal stripes along the flanks (vs. presence of such stripes in T. rarus); from T. carvalhoi in the shape of the patch of dark pigmentation on the caudal peduncle (a round blotch restricted to the posterior half of the caudal peduncle (vs. a lozenge-shaped blotch stretching out the whole extension of the caudal peduncle) and having 14-16 gill rakers on the lower limb of the first branchial arch (vs. 13); from T. argenteus by having 7-10 predorsal scales (vs. 13- 17); from T. araguaiensis by having 5-6 large dentary teeth (vs. 4), overall relatively smaller dentary teeth with pointed cusps (vs. overall robust dentary teeth with roundish cusps), longer snout 20.0- 27.6% (vs. 14.3-18.1% HL) and 14-16 gill rakers on the lower limb of the first gill arch (vs. 19-20); from T. denticulatus by the distance between the first and second humeral blotches (distant 1-1.5 scales from each other in horizontal direction vs. distant 3 scales from each other, respectively), and by the longer snout 20.0-27.6% (vs. 10.9-18.4% HL) (Ref. 96868).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Araujo, L.B.S. and P.H.F. Lucinda, 2014. A new species of the genus Tetragonopterus Cuvier, 1816 (Ostariophysi: Characiformes: Characidae) from the rio Tocantins drainage, Brazil. Neotrop. Ichthyol. 12(2):309-315. (Ref. 96868)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5020 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01122 (0.00514 - 0.02450), b=3.04 (2.87 - 3.21), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.2 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .