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); megaloplax: The species epithet megaloplax, from the Greek megalos, big and plax, plate, referring to the large lateral abdominal plate series present in the new species. A noun in apposition (Ref. 80996).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical; 28°S - 29°S
South America: Brazil. Known only from the headwaters of the rio Passo Fundo drainage, tributary to the upper rio Uruguay basin (Ref. 80996).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 4.7 cm SL male/unsexed; (Ref. 80996)
Morphology | Morphometrics
soft rays: 5. Hisonotus megaloplax differs from its congeners by the arrangement of abdominal plates,
which is composed by greatly enlarged lateral abdominal plates, which contact each other at the belly midline, without a median abdominal series or with a single triangular plate located posteriorly. All other species of Hisonotus, with the exception of Hisonotus montanus, possess a complete median series between the lateral abdominal plates or a naked area between them. This feature is polymorphic in H. montanus, some individuals having enlarged lateral abdominal plates contacting at the midline and leading to misidentification. Hisonotus megaloplax is further distinguished from Hisonotus montanus by the caudal-fin color pattern which is almost completely dark vs. color pattern composed by vertical dark stripes, and by the infraorbital canal entering infraorbital series via sphenotic vs. infraorbital canal entering infraorbital series via compound pterotic (Ref. 80996).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Carvalho, T.P. and R.R. Reis, 2009. Four new species of Hisonotus (Siluriformes: Loricariidae) from the upper rio Uruguay, southeastern South America, with a review of the genus in the rio Uruguay basin. Zootaxa 2113:1-40. (Ref. 80996)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00550 (0.00225 - 0.01343), b=3.11 (2.90 - 3.32), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.0 ±0.1 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months ().
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .