Actinopteri (ray-finned fishes) > Gymnotiformes
(Knifefishes) > Rhamphichthyidae
Etymology: Gymnorhamphichthys: Greek, gymnos = naked + Greek. Rhamphos = beak, bill + Greek, ichthys = fish (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; depth range - m (Ref. ), usually - m (Ref. ). Tropical; 0°C -
South America: upper Mamoré and Orinoco River basins.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 21.5 cm TL male/unsexed; (Ref. 2037)
Buried in the sand during the day, emerging at dusk and remain active until just before dawn (Ref. 10809). Field observation showed that the electric organ discharge (EOD) rate of this species start rising just before sunset, increasing to over 2-folds just after dark when the fish comes out of the sand, and decreasing when the fish returns to the sand well before dawn. Experimental studies suggest internal control of this cyclic behavior (Ref. 10810). There is evidence of fractional spawning; fecundity count was 65 eggs (Ref. 10644).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Mago-Leccia, F., 1994. Electric fishes of the continental waters of America. Fundacion para el Desarrollo de las Ciencias Fisicas, Matematicas y Naturales (FUDECI), Biblioteca de la Academia de Ciencias Fisicas. Matematicas y Naturales, Caracas, Venezuela. vol. 29 . 206 p. (Ref. 26457)
IUCN Red List Status (Ref. 124695)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5156 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00324 (0.00120 - 0.00869), b=3.09 (2.86 - 3.32), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.2 ±0.4 se; based on size and trophs of closest relatives
Vulnerability (Ref. 59153
): Low vulnerability (11 of 100) .