Trichomycterus sketi

Castellanos-Morales 2010

Trichomycterus sketi
Trichomycterus sketi. Photograph by Cesar Castellanos-Morales. Click for full screen view.


Trichomycterus sketi is a relatively recently evolved hypogean fish which has only incipient troglomorphies.






Holotype: CAC-CDMB 104 61.5mm SL. Paratypes: ANSP 189652 60.0mm SL, CAC-CDMB 105 55.9mm SL, CAC-CDNB 110 45.2mm and 55.3mm SL, IAvH-P 11806 45.7mm SL, MBUCV-V-35641 45.6mm SL, MLS 20.5mm SL, UIS-Th 1718 43.8mm SL.


Known only from the type locality: Cueva del Indio, vereda Casas Blancas, Municipio La Paz, Departmento de Santander, Colombia. 73o05'18"W, 6o50'21"N. Elevation 2157m.


There are no data on the relationships of this species.

Biological Notes

Florez et al. (2020) made a very thorough study of both epigean and hypogean Trichomycterus in the Province of Santander, Colombia. They were keen to understand whether the hypogean populations were derived from a single colonisation, evolution of troglomorphy and then dispersal to the known cave sites, or whether there had been multiple parallel colonisations followed by independent evolution of troglomorphy. Their data were quite clear that it was the second of these possibilities that had occurred and that some cave populations are very closely related to epigean ones.

Figure 2 of Florez et al. (2020) shows the relationships of all sampled Trichomycterus, and some other, taxa. The best supported clades are numbered 1-3 and hypogean Trichomycterus are found only in clades 1 and 2. Unnumbered clades received lower support and are not relevant here as they contain no troglomorphic taxa. Clade 1 consists of only the troglomorphic T. rosablanca and the widespread epigean species Eremophilus mutisii. Clade 2 is bigger and considerably more complex with 27 terminal taxa in four groups. Group 1 is monophyletic and consists of only the troglomorphic Trichomycterus undescribed species Guapota (3 terminals). Group 2 consists of two taxa, the non-troglomorphic Trichomycterus undescribed species Guadalupe (5 terminals) and the non-troglomorphic T. latistriatus (1 terminal). Group 3 is monophyletic and complex with 18 terminals. Three taxa are found in this group: T. sandavali (4 terminals), Trichomycterus undescribed species Zapatoca (7 terminals) and the hypogean, though apparently not troglomorphic T. uisae (7 terminals). Group 4 is monophyletic and consist of only the non-troglomorphic Trichomycterus undescribed species Curiti (3 terminals). From this set of data we can see that there are at least an additional two troglomorphic species in the genus that are not yet described, Guapota and Zapatoca. This takes the number of troglobitic species in the country to 12 with 5 currently undescribed. However, the lack of genetic structure in Group 3 strongly suggests that all terminals are very closely related and could be considered as the same species. If this were to be accepted then the formal name would be Trichomycterus sandovali Ardila Rodriguez 2006 and Zapoatoca need not be described.

Conservation Status

TLO [VU D1:3.1:2021]

Lasso, C. & Castellanos-Morales, CCM. 2021. Trichomycterus sketi. The IUCN Red List of Threatened Species 2021: e.T64792696A181734541. Accessed on 14 February 2022.

Museum Holdings

CAC-CDMB 139 49.1mm SL, MBUCV-V-35642 45.0mm SL.

Key References

Sket, B. Journal Article 1988 Speleobiological investigations in the Colombian Andes 1984
Ardila Rodríguez, C.A. Journal Article 2006 Trichomycterus sandovali, (Siluriformes: Trichomycteridae) a new species of a troglodytic fish (cave restricted) for the Department of Santander - Colombia. Peces del Departamento de Santander - Colombia
Castellanos-Morales, C.A. Journal Article 2007 Trichomycterus santanderensis: A new species of troglomorphic catfish (Siluriformes, Trichomycteridae) from Colombia
Castellanos-Morales, CA Journal Article 2008 Trichomycterus uisae: A new species of hypogean catfish (Siluriformes: Trichomycteridae) from the northeastern Andean Cordillera of Colombia
Castellanos-Morales, C.A., Marino-Zamudio, L.L., Guerrero, L. and Maldonado-Ocampo, J. Journal Article 2011 Peces del departamento de Santander, Colombia
Castellanos-Morales, C.A. and Galvis, F. Journal Article 2012 Las especies del genero Trichomycterus (Siluriformes: Trichomycteridae) en Colombia
Castellanos-Morales, C.A., Moreno, F., Malagón, L.M., Arango, Á.J., Pardo, D.D. and Méndez, M,A, Journal Article 2015 Aportes al conocimiento y uso de los ecosistemas subterráneos del municipio de La Paz (Santander).
Colihueque, N., Corrales, O, and Yáñez, M. Journal Article 2017 Morphological analysis of Trichomycterus areolatus Valenciennes, 1846 from southern Chilean rivers using a truss-based system (Siluriformes, Trichomycteridae)
DoNascimiento C., Herrera-Collazos E.E., Herrera-R G.A., Ortega-Lara A., Villa-Navarro F.A., Usma-Oviedo J.S. and Maldonado-Ocampo J.A. Journal Article 2017 Checklist of the freshwater fishes of Colombia: a Darwin Core alternative to the updating problem
Flórez, J.S., Cadena, C.D., DoNascimiento, C. and Torres, M. Journal Article 2020 Repeated colonization of caves leads to phenotypic convergence in catfishes (Siluriformes: Trichomycterus) at a small geographical scale
Flórez, J.S., Cadena, C.D., Donascimiento, C. and Torres, M. Journal Article 2021 Repeated colonization of caves leads to phenotypic convergence in catfishes (Siluriformes: Trichomycterus) at a small geographical scale
Lasso, C. and Castellanos-Morales, C.C.M. Web Page 2021 Trichomycterus sketi