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.
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.
(Sanchez-Duarte, P. 2016. Trichomycterus sketi. The IUCN Red List of Threatened Species 2016: http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T64792696A64890650.en. Downloaded on 11 July 2017).
CAC-CDMB 139 49.1mm SL, MBUCV-V-35642 45.0mm SL.
- Sket, B. (1988)
- Ardila Rodríguez, CA (2006)
- Castellanos-Morales, CA (2007)
- Castellanos-Morales, CA (2008)
- Castellanos-Morales, C.A., Marino-Zamudio, L.L., Guerrero, L. and Maldonado-Ocampo, J. (2011)
- Castellanos-Morales, C.A. and Galvis, F. (2012)
- Castellanos-Morales, C.A., Moreno, F., Malagón, L.M., Arango, Á.J., Pardo, D.D. and Méndez, M,A, (2015)
- 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. (2017)
- Colihueque, N., Corrales, O, and Yáñez, M. (2017)
- Flórez, J.S., Cadena, C.D., DoNascimiento, C. and Torres, M. (2020)
|Sket, B.||Journal Article||1988||Speleobiological investigations in the Colombian Andes 1984|
|Ardila Rodríguez, CA||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, CA||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).|
|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|
|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)|
|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|