Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Siluriformes
(Catfish) > Loricariidae
(Armored catfishes) > Hypoptopomatinae
Etymology: Hisonotus: Greek, isos = equal + Greek, noton = back (Ref. 45335); acuen: The specific name 'acuen' is in reference to the Xavante indigenous peoples, who in anthropological literature are known as 'acuen'. These people are constituted by the natives inhabiting the east of the Mato Grosso State, living in the margins of the rivers Culuene, Xingu, Mortes and Araguaia.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal. Tropical
South America: upper rio Xingu basin in Mato Grosso State, Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 2.9 cm SL male/unsexed; (Ref. 113800)
Morphology | Morphometrics
soft rays: 6;
Vertebrae: 27. Hisonotus acuen is distinguished from all congeners with the exception of H. bockmanni, H. chromodontus, H. insperatus, H. luteofrenatus, H. oliveirai and H. paresi by the possession of a functional V-shaped spinelet, (vs. non-functional spinelet, a square ossification, or spinelet absent). It can be diagnosed from H. insperatus, H. paresi, H. luteofrenatus, and H. oliveirai by having odontodes not forming longitudinally aligned rows on head and trunk (vs. odontodes forming longitudinally aligned rows on head and trunk). It differs from H. insperatus and H. luteofrenatus by having 4-5 lateral series of abdominal plates (vs. 6?8 and 7?8, respectively) and from H. insperatus by having 22-24 lateral median plates (vs. 25?26). It can be distinguished from H. luteofrenatus, H. oliveirai and H. paresi by having a single rostral plate at tip of snout (vs. presence of a pair of rostral plates at tip of snout); from H. bockmanni by the absence of unpaired platelets at typical adipose fin position (vs. presence of the unpaired platelets); from H. chromodontus by having yellowish tipped teeth (vs. reddish-brown teeth), caudal-fin color pattern mostly hyaline, except for dark blotch on origin of rays, and dark brown chromatophores largely concentrated on rays near lower caudal spine (vs. caudal-fin mostly dark brown with chromatophores largely concentrated on rays and membranes, and with two hyaline spots on middle of the fin); from H. paresi by the absence of conspicuous dark dorsal saddle and longitudinal stripe on the body (vs. inconspicuous dark saddles and stripe of the body) and from H. insperatus by having 14-27 premaxillary teeth (vs. 6?12) and 12-23 dentary teeth (vs. 5?11) (Ref. 106073).
Inhabits flat areas in creeks of headwaters of the rio Xingu basin in places of shallow clear waters with low current. Found associated with vegetation that covers the bottom and the border of the headwaters (Ref. 106073).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Silva, G.S.C., F.F. Roxo and C. Oliveira, 2014. Hisonotus acuen, a new and phenotypically variable cascudinho (Siluriformes, Loricariidae, Hypoptopomatinae) from the upper rio Xingu basin, Brazil. ZooKeys 442:105-125. (Ref. 106073)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 118484)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00832 (0.00273 - 0.02536), b=3.05 (2.80 - 3.30), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.5 ±0.1 se; Based on size and trophs of closest relatives
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .