Gymnorhamphichthys hypostomus
No common name
Collection Details
Specimens
Photos
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Records
Taxonomic Hierarchy
Rhamphichthyidae (Sand Knifefish)
Gymnorhamphichthys
Gymnorhamphichthys hypostomus
Description
This species account was compiled from
FishBase (Froese, R. and D. Pauly. Editors. 2025. FishBase. World Wide Web electronic publication. www.fishbase.org, version 04/2025.)
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Characters
Body shape: elongated.
Distribution
South America: upper Mamoré and Orinoco River basins.
Habitat Associations
Freshwater. benthopelagic.
Biology
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).
Max length: 21.5 cm TL.
IUCN Red List Status: Least Concern (LC), assessed 2020-11-18.
Commercial or Environmental Importance
Fisheries: of potential interest.
References
Eigenmann, R.S. (1912) The freshwater fishes of British Guiana, including a study of the ecological grouping of species, and the relation of the fauna of the plateau to that of the lowlands. Mem. Carneg. Mus. 5:578 p.
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.
Ferraris, C.J. Jr. (2003) Rhamphichthyidae (Sand knifefishes). p. 492-493. In R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.) Checklist of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, Brasil.
Comments On Gymnorhamphichthys hypostomus