Integrative taxonomy reveals a new species of the Hoplias malabaricus species complex (Teleostei: Erythrinidae)

ROSSO, J. J.; GONZÁLEZ-CASTRO M.; BOGAN, S.; CARDOSO, Y. P.; MABRAGAÑA E.; DELPIANI, S. M.; DÍAZ DE ASTARLOA, J. M.

ICHTHYOLOGICAL EXPLORATION OF FRESHWATERS

VERLAG DR FRIEDRICH PFEIL

Año: 2018

0936-9902

Surpassing 5000 species, the Neotropical fish fauna represents about one-third of all freshwater fishes worldwide. However, recent estimates regard a final diversity reaching 9,000 species. Habitat degradation in freshwater ecosystems is a major threat to biodiversity and many of these unknown species may disappear well before they can be described. In South America, fishes of the family Erythrinidae inhabit a large array of aquatic ecosystems. Bearing 13 valid species, the genus Hoplias is its richest member. Five species belong to the H. malabaricus group, but molecular results strongly suggested that this number largely underestimates the actual diversity within this group. By means of an integrative taxonomic approach, a new species of the H. malabaricus group from the La Plata River Basin is described. Hoplias argentinensis, new species, is characterized by: 17?19 predorsal scales, 42?43 vertebrae, 20 scales around caudal peduncle, no distinctive brown bands in lower jaw, last series of vertical scales on caudal fin nearly straight, 41?44 lateral-line scales and snout width (18.4?24.9 % of SL). Hoplias argentinensis is unambiguously discriminated from all other species of the H. malabaricus group by means of traditional characters, landmarks-based morphometrics and genetics. A key to species of the Hoplias malabaricus group is provided.