Rhizosomichthys totae Miles, 1942

Greasefish, Lake Tota feeler fish, Pez grasso, Tota catfish, Pez graso, Runcho



Taxonomy & Nomenclature

Synonym/s: Pygidium totae Miles, 1942 (protonym)


Conservation Status


Last record: 1957 or 1958

IUCN RedList status: Critically Endangered (Possibly Extinct)


"Several threats may impact this species of catfish, known from only a few unusual specimens found in lake Tota of the Colombian Andes (Mojica et al., 2012). Tectonic instability in the region where the fish is found causes earthquakes and possible landslides that may eliminate populations, and introduction of trout to the lake may bring competition with the fish, or predation on them, or even possibly the introduction of disease. However, the severity of these threats to the aquatic fauna is uncertain. Evidence of geologic events is not based on direct accounts, and there has not been a thorough study of the impacts of trout in the species' home lake. Thus P(local) is set with relatively broad bounds around a mid-value. The single lake from which the few specimens are known, is relatively well isolated high in the Andes (with one affluent stream and one effluent stream). However, local experts suggest it is possible that the species may be found in one of these connecting streams."

(Keith et al., 2017:324)



Lake Tota, Colombia


Biology & Ecology




SU 37074






Original scientific description:

Miles, C. (1942). Descripcion sistematica del “pez graso” del Lago de Tota (Boyacá). Caldasia 5: 55-58.


Other references:

Burgess, W. E. (1989). An atlas of freshwater and marine catfishes. A preliminary survey of the Siluriformes. T. F. H. Publications, Inc., Neptune City, New Jersey (USA). 784 pp.

Groombridge, B. (ed.). 1994. 1994 IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland and Cambridge, UK.

Keith, D. A., Butchart, S. H. M., Regan, H. M., Harrison, I., Ackakaya, H. R., Solow, A. R. and Burgman, M. A. (2017). Inferring extinctions I: a structured method using information on threats. Biological Conservation 214: 320-327.

Mesa-Salazar, L. & Mojica, J. 2016. Rhizosomichthys totae. The IUCN Red List of Threatened Species 2016: e.T19661A61472482. Accessed on 09 July 2022.

Mojica J. I., C. Castellanos, J. S. Usma, and R. Álvarez. (2002). Libro Rojo de los Peces Dulceacuicolas de Colombia. La serie libros rojos de especies amenazadas de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Ministerio del Medio Ambiente, Bogotá, D.C.

Mojica, J.I., Usma, J.S., Álvarez-León, R. and Lasso, C.A. 2012. Libro rojo de peces dulceacuícolas de Colombia. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá.

Schaefer, Scott A. and Fernández, Luis. (2009). Redescription of the Pez Graso, Rhizosomichthys totae (Trichomycteridae), of Lago de Tota, Colombia, and Aspects of Cranial Osteology Revealed by Microtomography. Copeia 2009(3): 510-522. [Abstract]

World Conservation Monitoring Centre. (1996). Rhizosomichthys totae. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. ( Downloaded on 01 February 2012.


<< Back to the Neopterygii (New-Finned Fishes) database