Taxonomic review of Neoplecostomus franciscoensis Langeani, 1990 (Loricariidae: Neoplecostominae)

Author(s)

Arieli Matheus Cherobim

• Document type: Master's Dissertation
• Press: São José do Rio Preto. 2016-03-24.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2016-02-25
• Advisor: Francisco Langeani

Abstract

The diversity in Neoplecostomus Eigenmann & Eigenmann, 1888 increased considerably last years. In the only taxonomic revision available for the genus, Langeani (1990) recognized only one species from the upper rio Paraná basin, N. paranensis, and also only one species from the rio São Francisco drainage, N. franciscoensis. Further studies revealed the occurrence of other species from the upper rio Paraná, totaling eight species from the drainage. However, since the description of N. franciscoensis 25 years ago, no analysis was performed in the rio São Francisco basin, the second largest drainage to harbor the genus. Thus, the aim of this study was to review the Neoplecostomus populations occurring in this basin. Results demonstrate the occurrence of two species: N. franciscoensis stricto sensu, from affluents of the rio das Velhas and Neoplecostomus sp. n., from headwater streams of the rio São Francisco surrounding Serra da Canastra National Park and affluents of the rio Paraopeba. Neoplecostomus franciscoensis present spinelet absent or with varied size and disposition (vs.spinelet always wider than dorsalfin spine base in Neoplecostomus sp. n.) and two or three large plates arranged in line, and above them several small plates between the cleithrum humeral process and the first plate of the lateral series (vs. one large plate between the cleithrum humeral process and the first plate of the lateral series in Neoplecostomus sp. n.). Furthermore, in N. franciscoensis there is no difference in the number of teeth between males and females (12-22 (15) teeth in the premaxillary and 10-20 (12) teeth in the dentary). Already in Neoplecostomus sp. n., females present more number of teeth in the premaxillary (17-34 (23) vs. 18-20 (20) in males) and in the dentary (11-33 (15) vs. 13-19 (14) in the males). Additionally, N. franciscoensis present the anterior extremity of the second basibranchial greater than posterior extremity (vs. extremities without any difference in the development in Neoplecostomus sp. n.) and lateral process in the first anal-fin pterygiophore absent or inconspicuous (vs. narrow lateral process in Neoplecostomus sp.n.). (AU)

• FAPESP's process: 13/26865-8 - Taxonomic review of Neoplecostomus franciscoensis Langeani, 1990 (Loricariidae: Neoplecostominae)
• Grantee: Arieli Matheus Cherobim
• Support Opportunities: Scholarships in Brazil - Master