Knodus shinahota (Characiformes: Characidae) a new species from the río Shinahota, río Chapare basin (Mamoré system), Bolivia

Abstract

Knodus shinahota, new species, is described from río Shinahota, a tributary of the upper rio Mamoré basin, Província de Tiraque, Cochabamba State, Bolivia. The new species can be distinguished from all congeners except K. chapadae and K. geryi by having six rows of scales between the lateral line and the dorsal-fin origin (vs 4 or 5 rows of scales in the other species). Knodus shinahota differs from K. chapadae by possessing more rows of scales between the lateral line and the pelvic-fin origin (5 vs 3½ or 4, respectively) and more lateral line scales (38-41 vs 36-38, respectively). It differs from K. geryi by possessing more rows of scales between the lateral-line and the pelvic-fin origin (5 vs 4, respectively); fewer branched anal-fin rays (17-20 vs 15-17, respectively), and by lacking the two symmetric, large, dark, blotches on the basal portions of the caudal-fin lobes that characterize K. geryi.Knodus shinahota, espécie nova, é descrita do río Shinahota, um afluente do alto da bacia do rio Mamoré, Província de Tiraque, Estado de Cochabamba, Bolívia. A espécie nova pode ser distinguida de todas as suas congêneres exceto K. chapadae e K. geryi por ter seis fileiras de escamas entre a linha lateral e a origem da nadadeira dorsal (vs 4 ou 5 fileiras de escamas nas demais espécies). Knodus shinahota difere de K. chapadae por possuir mais fileiras de escamas entre a linha lateral e a origem da nadadeira pélvica (5 vs 3½ ou 4, respectivamente) e mais escamas na linha lateral (38-41 vs 36-38, respectivamente). Difere de K. geryi por possuir mais fileiras de escamas entre a linha lateral e a origem da nadadeira pélvica (5 vs 4, respectivamente); menos raios ramificados na nadadeira anal (17-20 vs 15-17, respectivamente), e pela falta das duas grandes manchas escuras, simétricas, basalmente nos lobos da nadadeira caudal que caracteriza K. geryi.

Deep barcode divergence in Brazilian freshwater fishes: the case of the São Francisco River basin

“…However, the genus Knodus has not yet been described for the SFR. In addition, Knodus is differentiated from Bryconamericus by a sole feature, the presence of scales on the basal portion of the caudal fin in Knodus (Ferreira and Carvajal 2007). We therefore suggest that the range of occurrence of K. moenkhausii should be extended to the SFR.…”

Knodus dorsomaculatus (Characiformes: Characidae), a new species from Teles Pires River, Tapajós River basin, Brazil

“…Given the variation observed here, a more comprehensive analysis of the number of dorsal fin rays in other clade A characids genera of Malabarba & Weitzman (2003) is necessary for a better understanding of the significance of this character as a putative synapomorphy for the group. Even though K. dorsomaculatus presents the plesiomorphic condition for Characidae, the decision to assign it to Knodus was based on the fact that it shares all the other common features currently used to define the genus: the presence of two rows of teeth on the premaxillary; four teeth on the inner tooth row; two to four teeth on the maxilla; teeth of dentary with cups oriented posteriorly with median cusps larger than the lateral cusps; four or more rows of scales covering the basal portions of the dorsal and ventral caudal fin lobes; eight pelvic fin rays with the first and last rays unbranched (Lima et al , 2004; Ferreira & Lima, 2006; Ferreira & Carvajal, 2007).…”

“…Knodus is currently assigned as an incertae sedis group within the Characidae (Lima et al , 2003) and encompasses 22 recognized species known from the Amazon, Paraná‐Paraguay, Parnaíba and São Francisco River basins (Lima et al , 2003, 2004; Ferreira & Lima, 2006; Zarske & Géry, 2006; Ferreira & Carvajal, 2007; Zarske, 2007, 2008). Recent collecting efforts in the Teles Pires River system yielded a new species of Knodus that is described in this article.…”

New and poorly known Characiform fishes (Teleostei: Characiformes: Characidae) from French Guyana. A new Tetra of the genus Bryconamericus

“…There are authors which accept Knodus as a valid genus (e.g. GÉRY, 1978;LIMA et al, 2004;ZAR-SKE & GÉRY, 2006;FERREIRA & LIMA, 2006;FERREIRA & CARVAJAL, 2007;ZARSKE, 2007ZARSKE, , 2008VARI et al, 2009, and others) and authors which do not accept Knodus (THAPHORN, 1992;ROMAN-VALENCIA, 2003, 2005. Here we accept Knodus because the phylogenetic relationships of the whole old Tetragonopterinae is not solved and if we do not accept the differentiation between Bryconamericus and Knodus so we also can not accept for example the differentiation between Astyanax and Moenkhausia or Hyphessobrycon and Hemigrammus.…”