Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Gymnotiformes
(Knifefishes) > Gymnotidae
Etymology: Gymnotus: Greek, gymnos = naked (Ref. 45335); capitimaculatus: Derived from the Latin subject capitis (head) and adjective maculatus (blotchy), in reference to the presence of a pair of blotches in the ventral portion of the head.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal. Tropical
South America: Rio do Ouro, rio Jucuruçu basin in Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 15.8 cm TL male/unsexed; (Ref. 96661)
Morphology | Morphometrics
Gymnotus capitimaculatus belongs to the Gymnotus pantherinus species-group, characterized by having a slender body (body depth 7.2-8.9 % of TL), proximal portion of the fifth rib with broad triangular ridge, more than three times width of the sixth rib (vs. narrow ridge, less than three times width of the sixth rib) and one laterosensory pore in the dorso-posterior portion of the preopercle, in the preopercular-mandibular canal (vs. two pores). It differs from all congeners by having a pair of round blotches anteriorly positioned or under vertical passing through eye, on ventral portion of the head. It can be diagnosed from all members of the G. pantherinus species-group (sensu) by the following unique combination of characters: tail with a unique series of bands or round spots (vs. tail with randomly disposed spots, never forming a unique series); precaudal portion of the trunk lacks bands or with rounded and/or vermiculated spots scattered all over it (vs. with well defined bands); 45 precaudal vertebrae (vs. 31-43 or 46-51); 9 scales above lateral line at mid-body (vs. 6-8 or 10); anal fin base length 75.2-78.6 % of TL (vs. 62.9-74.7 or 79-83.8 %); anus-anal fin length 101.4-122.8 % of HL (vs. 50-96.3 %); and branchial opening 38.5-45.0 % of HL (vs. 24-35) (Ref. 96661).
Occurs in clear water stream with topical width of about 1.5 m, depth range from 0.1 to 1 m and bottom consisting of sand and small gravel. Individuals were deeply hidden among marginal vegetation and roots, mostly where the water flow was faster. Inhabits sympatrically with another species of Gymnotus belonging to the G. carapo species group, but not syntopically (Ref. 96661).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Rangel-Pereira, F.S., 2014. Gymnotus capitimaculatus, a new species of electric fish from rion Jucuruçu basin, northeastern Brazil (Ostariophysi: Gymnotiformes: Gymnotidae). Vert. Zool. 64(2):169-175. (Ref. 96661)
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
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00589 (0.00179 - 0.01938), b=2.97 (2.71 - 3.23), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (15 of 100) .