Description of two new species of Hisonotus Eigenmann & Eigenmann, 1889 (Ostariophysi, Loricariidae) from the rio Paraná-Paraguay basin, Brazil

By

Roxo, Fábio
Zawadzki, Cláudio Henrique
Troy, Waldo

Type

Article

Date of Publication

2014

Original Publication

ZooKeys

Volume

395

Pages

57-78

Subjects

Cascudinhos , Fresh Water , head plates , Hypoptopomatinae , Neotropical fish

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.395.6910

 

Abstract

Two new species of Hisonotus are described from the rio Paraná-Paraguay basin in Brazil. The most remarkable features of the new species are the odontodes forming longitudinally aligned rows (one odontode after the other, but not necessarily forming parallel series) on the head and trunk (vs. odontodes not forming longitudinally aligned rows), a pair of rostral plates at the tip of the snout (vs. a single rostral plate), the functional v-shaped spinelet (vs. spinelet non-functional, square-shaped, or absent). These features suggest close phylogenetic relationships with Hisonotus bockmanni, H. insperatus, H. luteofrenatus and H. piracanjuba. Additionally, both new species are distinguished from their congeners by characters related to head length and depth, orbital diameter, suborbital depth, caudal peduncle depth, pectoral-fin spine length, snout length and counts of teeth. Hisonotus paresi sp. n. further differs from its congeners bycontrasting dark geometric spots on the anterodorsal region of the body, a character lacking in H.oliveirai sp. n. The variation in number and shape of the rostral plate, posterior rostrum plates, infraorbitals and the preopercle in both new species and in H. insperatus are discussed.