A new subterranean species of Phreatobius Goeldi, 1905 (Siluriformes, Incertae sedis) from the Southwestern Amazon basin

Abstract

A new species of the previously monotypic catfish genus Phreatobius is described from an artificial well in the village of Rio Pardo, located 90 km south of the city of Porto Velho, State of Rondônia, Brazil, in the drainage area of the Rio Branco (Rio Madeira system, Amazon basin). Phreatobius dracunculus n. sp. differs from its only congener, P. cisternarum, by the absence of eyes (vs. present), the lack of dark integumentary pigmentation (vs. faint dark pigment always present), the presence of five pectoral-fin rays (vs. four), ventral procurrent rays 11-13 (vs. 22 to 26), dorsal procurrent rays 29-31 (vs. 42 to 50), fewer vertebrae (52 or 53 vs. 59 to 64) and the larger pseudotympanus. The new species shows all diagnostic characters so far proposed for Phreatobius, including an unusual red coloration in life. The localities of the two species of Phreatobius are approximately 1900 km apart. That, in association with their peculiar and mostly inaccessible habitats, indicates that the genus may be widely distributed in the Amazon basin.

The adductor mandibulae muscle complex in lower teleostean fishes (Osteichthyes: Actinopterygii): comparative anatomy, synonymy, and phylogenetic implications

“…In at least some members of most families of the Siluriformes, the origin of the malaris expands dorsally onto the neurocranium (Fig. ) and in more derived conditions the dorsally enlarged contralateral malares contact each other midsagittally (McMurrich, ; Juge, ; Takahasi, ; Eaton, ; Alexander, ; Howes, ; Grande & Lundberg, ; Lundberg, Bornbusch & Mago‐Leccia, ; de Pinna & Vari, ; Adriaens & Verraes, ; Cabuy et al ., ; Devaere et al ., , ; Herrel et al ., ; Rodiles‐Hernández et al ., ; Sarmento‐Soares & Porto, ; de Pinna, Ferraris & Vari, ; Shibatta, Muriel‐Cunha & de Pinna, ; Datovo & Bockmann, ). The malaris inserts on the buccopalatal membrane plus the maxilla in the Callichthyidae (see below) and on the lower jaw in both all other examined siluriforms and those for which the muscle was described in the literature (Fig.…”

“…This condition is present in most siluriforms, including all members of the primitive families Diplomystidae and Cetopsidae (Fig. ; McMurrich, ; Juge, ; Takahasi, ; Eaton, ; Alexander, ; Howes, ; Grande & Lundberg, ; Lundberg et al ., ; de Pinna & Vari, ; Adriaens & Verraes, ; Cabuy et al ., ; Herrel et al ., ; Rodiles‐Hernández et al ., ; Devaere et al ., , ; Sarmento‐Soares & Porto, ; de Pinna et al ., ; Shibatta et al ., ; Datovo & Bockmann, ), and at least in the Gymnotidae (Fig. A; Aguilera, ), the basal‐most gymnotiform family according to the morphologically based phylogenetic analysis by Albert ().…”

Behaviour, feeding habits and ecology of the blind catfish Phreatobius sanguijuela (Ostariophysi: Siluriformes)

“…occur in wells of different depths. Phreatobius sanguijuela was found in wells at depths from 4·0 to 7·3 m. Fernandez et al (2007) collected the only three individuals known hitherto in wells at depths from 6·0 to 12·0 m. Phreatobius cisternarum has been collected in 4-20 m deep wells (Carvalho, 1967;Muriel-Cunha & de Pinna, 2005) and P. dracunculus in a 5 m deep well (Shibatta et al, 2007). In this study, P. dracunculus was collected in wells ranging from 4 to 7 m, but this study found that the depth of the well does not influence the occurrence of P. sanguijuela and that its presence or absence may be related to the water quality in the wells.…”

“…Phreatobius sanguijuela was found in wells at depths from 4·0 to 7·3 m. Fernandez et al () collected the only three individuals known hitherto in wells at depths from 6·0 to 12·0 m. Phreatobius cisternarum has been collected in 4–20 m deep wells (Carvalho, ; Muriel‐Cunha & de Pinna, ) and P . dracunculus in a 5 m deep well (Shibatta et al , ). In this study, P .…”

“…cisternarum and P . dracunculus (Muriel‐Cunha & de Pinna, ; Shibatta et al , ), stressful conditions temporarily induced a vertical body position in individuals of P . sanguijuela .…”