Subterranean Fishes of the World

Country

Types

Holotype: FML 2590, 29.4 mm SL. Paratypes: AMNH 233621 18.5 mm SL, FLBS 01071A 18.7 mm SL, FML 2591, 2, 24.5 mm SL, FML 2592 19.6 mm SL, FML 2594, 2, 25.4mm SL, MZUSP 83359 27.7 mm SL.

Distribution

Known only from a series of artificial wells which penetrate a phreatic aquifer near Río Arenales at San Luis, Departamento Capital, Provincia de Salta, western Argentina. 24°50'S, 65°30'W. Altitude 1273m.

These wells are in the biogeographic unit Central Pacific and drainage basin Bermejo of Schaefer (2011:268-273). These wells are in the Panpean biogeographic province of Lopez et al. (2008).

Habitat

The nature of the phreatic aquifer inhabited by Silvinichthys bortayro is not known. The wells where it is caught contain clear water to a depth of 7-12m with a sandy substrate.

Systematics

There are currently seven species in the genus Silvinichthys Aratia 1998 (Eschmeyer, Fricke, and van der Laan 2021), five of them in Argentina (S. bortayro, S. gualcamayo, S. huachi, S. leoncitensis and S. mendozensis - Mirande and Koeber 2015). Four of these (S. bortayro, S. gualcamayo, S. huachi and S. leoncitensis) lack the pelvic girdle and pelvic fins and this synapomorphy unites these four into a monophyletic group. Within this group S. bortayro and S. huachi share a reduction in the number of branched pectoral-fin rays (5 or 6 vs. 7 to 9 in other Silvinichthys species and most trichomycterins) and it is hypothesized that S. huachi is the sister species to S. bortayro (Fernandez, Sanabria, Quiroga and Vari 2014). Hoever, there is a distance of 800km between the type localities of these two species.

Museum Holdings

As above plus: FACEN40 (Fernandez et al. 2021).