New Species of Jenynsia (Teleostei: Cyprinodontiformes) from Southern Brazil and Its Phylogenetic Relationships

A new species of Jenynsia from southern Brazil is described. Jenynsia weitzmani n. sp. from the rio Pinheiros drainage in Santa Catarina state is diagnosed by a single dark midlateral stripe, absence of associated dark dorsolateral or ventrolateral stripes or blotches in adults, a terminal to slightly oblique mouth, and absence of the first mandibular-canal pore (pore W). A phylogenetic analysis of primarily osteological data supported the new species as sister to a group composed of J. eirmostigma and J. eigenmanni within the subgenus Plesiojenynsia. A key to Jenynsia species is provided.

Resumen

Uma nova espécie do gênero Jenynsia do sul do Brasil é descrita. Jenynsia weitzmani sp. nov., das drenagens do rio Pinheiros, estado de Santa Catarina, é diagnosticada por uma única faixa lateral escura, ausência de faixas ou manchas dorso-laterais escurasou ventro-laterais associadas nos adultos, boca terminal a ligeramente oblíqua e ausência do primeiro poro do canal mandibular (poro W). Uma análise filogenética de dados principalmente osteológicos sustentou a nova espécie como a espécie-irmã de um grupo composto por J. eirmostigma e J. eigenmanni dentro do subgênero Plesiojenynsia. Uma chave para as espécies de Jenynsia é apresentada.

Fig. 1.

Jenynsia weitzmani n. sp. Top: MCP 25559 (holotype), female, 50.8 mm SL; bottom: MCP 17615 (paratype), male, 42.3 mm SL

Fig. 3.

Strict consensus of three equally most-parsimonious phylogenetic trees. Outgroups not included. Tree statistics based on fundamental trees from the analysis using the outgroup topology proposed by Parenti (1981). Statistics from all analyses presented in text. Branch lengths based on ACCTRAN optimization above branches, Bremer (1988) decay indices below branches. Symbols associated with Plesiojenynsia species correspond to those in Figure 4

Fig. 2.

Semidiagrammatic representation of mouth position (indicated by arrow) and pigmentation patterns in species of the subgenus Plesiojenynsia: (A) Jenynsia weitzmani; (B) Jenynsia unitaenia; (C) Jenynsia eirmostigma; (D) Jenynsia eigenmanni

Fig. 4.

Distributions of species in the subgenus Plesiojenynsia. The type locality of Jenynsia weitzmani is indicated by a star. Known distribution of Jenynsia eigenmanni shown as triangles. Known distribution of Jenynsia eirmostigma shown as squares. Known distribution of Jenynsia unitaenia shown as circles

Accepted: 26 Feb 2001