Neoplecostominae Regan 1904

Abstract

Subfamily NEOPLECOSTOMINAE Regan, 1904 Neoplecostominae Regan, 1904: 306. Type genus: Neoplecostomus Eigenmann & Eigenmann, 1888. Included genera. Hirtella Pereira, Zanata, Cetra & Reis, 2014; Isbrueckerichthys Derijst, 1996; Kronichthys Miranda Ribeiro, 1908; Neoplecostomus Eigenmann & Eigenmann, 1888; Pareiorhaphis Miranda Ribeiro, 1918; Pareiorhina Gosline, 1947; and Euryochus n. gen. Diagnosis. Neoplecostominae is diagnosed by one exclusive synapomorphy: Anteriormost pleural ribs connected to vertebral centra via ligament, while posterior ribs directly articulated (Char. 135.1). Non-exclusive synapomorphies include: Posterodorsal laminar expansion of upper pharyngeal tooth plate present (Char. 48.1), posterodorsal margin of lateral ethmoid with small expansion forming articular facet for articulation with metapterygoid (Char. 86.1), metapterygoid with complete suture to hyomandibula along its entire posterior margin (Char. 90.2), one bifid hemal spine next to anal fin (Char. 127.1), and posterior process of coracoid straight and projected posteriorly (Char. 159.1). Comparisons. The species of Neoplecostominae are distinguished from most other loricariids (except the Hypoptopomatinae) by having a posterior expansion on the ventromesial process of the pelvic-fin spine for the insertion of the abductor superficialis muscle (see character 204; Fig. 37 B). In addition, the Neoplecostominae are distinguished from most other loricariids by the thickness of the ventral surface of pelvic-fin spine of adult males, where the ray is widened and its ventral surface is flat, and the transverse section is roughly triangular (also shared with Lithogenes and few hypoptopomatines; vs. pelvic-fin spine roundish in cross-section). The Neoplecostominae are further distinguished from the Hypoptopomatinae by possessing a pectoral girdle completely covered by skin or dermal plates (vs. a pectoral girdle completely or partially exposed ventrally, and supporting odontodes). From the Lithogeninae, they are further distinguished by a simple pelvic-fin spine (vs. a partially bifurcate pelvic-fin spine) and by having the body entirely covered by dermal plates (except for Pareiorhaphis nudulus). Neoplecostominae can be further distinguished from the Delturinae by their lack of a pronounced preadipose ridge typical of the latter subfamily, and by possessing asymmetrical cusps on the dentary and premaxillary teeth (vs. approximately symmetrical cusps). From the Hypostominae, they are further distinguished by possessing a roundish or rectangular dorsal-fin spinelet, when present (vs. typically a V -shaped dorsal-fin spinelet). The Neoplecostominae are further distinguished from the Loricariinae by possessing a deep caudal peduncle, that is vertically ovoid or approximately triangular shape in cross-section, and by usually possessing an adipose fin (vs. a caudal peduncle conspicuously depressed and adipose fin absent).