Trichomycterus undescribed species
[Perez and Moodie 1993]
Trichomycterus species from Guacharo Cave, Venezuela
The Guacharo Cave, Venezuela (10o10’33”N, 63o33’06”W) is famous both for the visit to it by Humboldt, and for its enormous population of oil birds, Steatornis caripensis. (For a schematic outline of the cave and details of these birds see Bellard Pietri (1957, 1960) and Brosset (1998)). In addition to the birds the cave also contains fishes and these have been studied by various workers over the years. Schultz (1949) identified these fishes as Pygidium conradi but said no more about them. Nalbant and Linares (1987) made a more detailed study, decided that both generic and specific placements were incorrect, and said that the fishes were Trichomycterus guianense. In the same year Romero (1987) published some experimental results on these animals under the name Trichomycterus conradi, suggesting that the animals breath air. Andreani (1987, 1990) made a thorough morphometric study of fishes from within and outside of the cave and concluded that neither of them were conradi. The latest published work, that of Perez and Moodie (1993), suggests that the taxonomy requires re-evaluation and refers to the fishes simply as Trichomycterus sp.. They make the significant remark: “...we analysed genetic variation within a troglobite (obligatory cave-dweller) population of catfish belonging to the genus Trichomycterus that inhabits a subterranean stream in Guacharo Cave, and within an epigean population of the same genus living in a small stream outside the cave”. They clearly consider the cave fishes to be troglobitic. However their measurements of variation suggest that the epigean and hypogean populations are very closely related, and they suggest that either there has been a very recent separation of the populations or that there remains genetic continuity between them. Morphologically the cave population is only slightly different from the epigean one and shows no troglomorphic features. This species should be described as new.
|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)|