Trichomycterus rubbioli

description

Description. Morphometric data of holotype and paratypes are given in Table 1.

A new species of cave catfish from Brazil, Trichomycterus rubbioli sp. n., from Serra do Ramalho karstic area, São Francisco River basin, Bahia State (Silurifomes: Trichomycteridae)

diagnosis

Diagnosis. Trichomycterus rubbioli is readily distinguished from epigean and most hypogean congeners by three distinctive, non-exclusive characters: highly reduced skin pigmentation (except for T. gorgona and caverestricted congeners, T. chaberti, T. itacarambiensis, T. spelaeus, T. sandovali, T. santanderensis, T. uisae and T. dali) (Fig. 2); reduced eyes, visible externally as small black or reddish-brown spots (except for T. gorgona and the hypogean T. chaberti, T. itacarambiensis, T. santanderensis, T. uisae and T. sketi) (Figs. 2 and 3); and barbels long, especially nasal (86.9 – 127.1 % of HL) and maxillary (98.1 – 129.3 % of HL) (except for T. longibarbatus and the hypogean T. spelaeus, T. santanderensis, T. uisae, T. sketi and T. dali) (Figs. 2 and 3). The characters above, in combination, differentiate new species from all hypogean congeners except for T. santanderensis and T. uisae. Trichomycterus rubbioli can be further diagnosed from almost all congeners, including T. santanderensis and T. uisae (except for T. hualco, T. sketi and T. dali) by pectoral-fin ray count reaching I, 9.

A new species of cave catfish from Brazil, Trichomycterus rubbioli sp. n., from Serra do Ramalho karstic area, São Francisco River basin, Bahia State (Silurifomes: Trichomycteridae)

distribution

Distribution. Trichomycterus rubbioli is known exclusively from subterranean waters in at least two caves of the same cave system in the Serra do Ramalho karst area, middle São Francisco River basin: Lapa dos Peixes and Gruna da Água Clara (Fig. 1). Notes on habitat and ecology. The small vadose stream inside Lapa dos Peixes where T. rubbioli catfishes were found is about 180 m long (accessible part), with an average width of 0.3 m and maximum depths of 0.5 m. The fishes were concentrated in places with the bottom formed by clay and small blocks of limestone, usually hiding under these blocks and inside crevices in the walls, thus showing a strong cryptobiotic habit. The level of water in this stream is lower in the dry season, and on two occasions the locality was mostly dry. Non-troglobitic fish, such as tetra characins, Astyanax sp., and heptapterids, Rhamdia sp. and Pimelodella sp., were observed in the locality (Trajano et al., 2009). In April 2000 and September 2003, respectively, 15 and 17 specimens of T. rubbioli were counted along the 180 m long stream, but afterwards this number sharply decreased (see Trajano et al., 2009: Table 1), which suggests that the population in t

A new species of cave catfish from Brazil, Trichomycterus rubbioli sp. n., from Serra do Ramalho karstic area, São Francisco River basin, Bahia State (Silurifomes: Trichomycteridae)

etymology

Etymology. The specific name (noun in apposition) is in honor of Ezio Rubbioli, speleologist, the first explorer of Serra do Ramalho caves, who brought this new species to our attention.

A new species of cave catfish from Brazil, Trichomycterus rubbioli sp. n., from Serra do Ramalho karstic area, São Francisco River basin, Bahia State (Silurifomes: Trichomycteridae)