Abstract
A new genus and species of glandulocaudine, Lophiobrycon weitzmani, is described based on specimens collected in headwater tributary streams of the rio Grande, upper rio Paraná system, State of Minas Gerais, southeastern Brazil. The inclusion of the new species in the phylogeny of the subfamily Glandulocaudinae proposed by Weitzman & Menezes (1998), reveals a sister group relationship between the new genus and the monophyletic group composed of Glandulocauda and Mimagoniates that currently form the tribe Glandulocaudini. The new species can be readily distinguished from all other species of the tribe by the autapomorphic presence in adult male individuals (with more than 23.9 mm standard length) of an adipose-fin whose base extends for almost the entire distance between the posterior terminus of the base of the dorsal fin and the base of the upper lobe of the caudal fin and averages approximately 25% standard length, along with the presence of globular expansions formed by the lepidotrichia and hypertrophied soft tissue in the middle portions of the first and second pectoral-fin rays. The diagnosis of the tribe Glandulocaudini is modified to accommodate the new genus.
Highlights
The Glandulocaudinae are a group of 20 genera and approximately 60 species of small sized characiform fishes that occur in practically all major South American drainages
Recent findings have shown that inseminating characids other than the Glandulocaudinae have elongated sperm nuclei, in absence of published hypothesis on the distribution and homology of these characters, we keep the diagnosis of the Glandulocaudinae as proposed by Weitzman & Menezes (1998)
The genus Glandulocauda not supported by any synapomorphies was kept as a separate genus, that was defined by the absence, in the adult males, of a caudal-fin ray pump like the derived one found in Mimagoniates, formed by highly modified caudal-fin rays 10-12, associated to the presence of hypertrophied glandular tissue confined to the area immediately around and on the caudal pump region of the gland
Summary
The Glandulocaudinae are a group of 20 genera (including Lophiobrycon described ) and approximately 60 species of small sized characiform fishes (less than 130 mm in standard length) that occur in practically all major South American drainages. In the tribe Glandulocaudini, in which the new species is included, the adult males possess a unique kind of caudal-fin ray pheromone pump that consists of hypertrophied glandular tissue associated with modified caudal-fin scales and the principal fin rays. This structure is apparently used to signal females during courtship (Weitzman & Burns, 1995; Weitzman & Menezes, 1998). The rio Grande, upper Paraná River System, State of Minas Gerais, in southeastern Brazil (Fig. 3)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
