Taxonomic status ofBathysolea profundicola andB. polli (Soleidae; Pleuronectiformes) with notes on the genus

Abstract

The objectives of this study were to i) clarify the taxonomic status and provide redescriptions of the deepsea soleid speciesBathysolea profundicola andB. polli (Pleuronectiformes), ii) discuss the taxonomic status ofB. lactea andB. lagarderae and iii) examine the monophyletic status of the genus. One hundred and fifteen specimens including most available type material were examined.B. profundicola andB. polli can be differentiated by their dorsal fin pterygiophore complex over the cranium, number of dorsal fin rays, angle between the dorsal and ventral branches of the urohyal and relative length of the posteriormost ray of the dorsal fin. Both species also share a unique diagnostic combination of traits among soleids and are hypothesized to be sister species. This study confirmed thatCapartella longisquamis andSolea greeni are junior synonyms ofBathysolea profundicola. Bathysolea lactea, known only from the description of the lost holotype, remains valid pending the capture of more specimens from Cabo Verde Islands. Two apomorphic characters define the genus as monophyletic: the filamentous structure of the pectoral fins and the presence of dark pigmentation inside the abdominal and branchial cavities. However, contradictory evidence from a study of the supracranial dorsal fin pterygiophore complex indicated that B. lagarderae, a deep-sea species endemic to the coasts of Madagascar, and the eastern Atlantic clade,B. profundicola-B. polli, might be more closely related to other soleid taxa than to each other. Until a revision of the family Soleidae is completed, it is preferable to maintain all of the abovementioned species withinBathysolea. An identification key to species in the genus is provided.