Species delimitation reveals an underestimated diversity of Andean catfishes of the family Astroblepidae (Teleostei: Siluriformes)

Abstract

Catfishes of the family Astroblepidae form a group composed by 82 valid species of the genus Astroblepus inhabiting high-gradient streams and rivers throughout tropical portions of the Andean Cordillera. Little has been advanced in the systematics and biodiversity of astroblepids other than an unpublished thesis, a single regional multilocus study and isolated species descriptions. Here, we examined 208 specimens of Astroblepus that apparently belong to 16 valid species from several piedmont rivers from northern Colombia to southern Peru. Using three single-locus approaches for species delimitation in combination with a species tree analysis estimated from three mitochondrial genes, we identified a total of 25 well-delimited lineages including eight valid and 17 potential undescribed species distributed in two monophyletic groups: the Central Andes Clade, which contains 14 lineages from piedmont rivers of the Peruvian Amazon, and the Northern Andes Clade with 11 lineages from trans- and cis-Andean rivers of Colombia and Ecuador, including the Orinoco, Amazon, and Magdalena-Cauca basins and Pacific coastal drainages. Results of species delimitation methods highlight several taxonomical incongruences in recently described species denoting potential synonymies.

Fish Ecology of the Alto Madre de Dios River Basin (Peru): Notes on Electrofishing Surveys, Elevation, Palm Swamp and Headwater Fishes

“…We found five different species of Astroblepus (Figure 5), two of them undetermined, five species of Bryconamericus, and six species of Trichomycterus all undetermined (Figure 4). Astroblepids and trichomycterids are typically restricted in their geographical distribution and endemic to single or adjacent river systems of the Andes, and their taxonomy is poorly known and in constant revision [76][77][78]. Advances on the taxonomic and ecological knowledge of these high mountain species, related to tropical montane cloud forests, are mandatory for the design of conservation and management plans in the area.…”

Conservation threats and future prospects for the freshwater fishes of Ecuador: A hotspot of Neotropical fish diversity

“…In Ecuador, there are 24 recognized species of Astroblepus , of which 17 are listed as endemic (Barriga, 2012 ). Very little is known about the ecology or distribution of most species of Ecuadorian Astroblepus , a problem that is made worse by the taxonomic uncertainties plaguing this genus (Ochoa et al ., 2020 ; Schaefer et al ., 2011 ). Given the magnitude of the threat and the high rates of endemism, studies on the impacts of climate change on Andean fishes are urgently needed, as is a comprehensive taxonomic review of the genus Astroblepus in the Ecuadorian Andes.…”

“…Astroblepus, a problem that is made worse by the taxonomic uncertainties plaguing this genus (Ochoa et al, 2020;Schaefer et al, 2011).…”

Phylogeography of Hypomasticus copelandii (Teleostei, Anostomidae) Reveals Distinct Genetic Lineages along Atlantic Coastal Drainages of Eastern Brazil

“…The conservation of mega-biodiversity obtained over hundreds of millions of years depends on accurate species identification, especially in ecosystems highly impacted by anthropogenic activities [11,12]. However, the assessment of such biological diversity is complex due to the high number of described and undescribed species [13,14], the lack of phenotypic variation in cryptic species [15,16], and the inadequate funding and training for taxonomic research [17,18].…”