Jenynsia lineata species complex, revision and new species description (Cyprinodontiformes: Anablepidae)

Abstract

The Jenynsia lineata species complex comprises J. lineata from Montevideo, Uruguay and Jenynsia multidentata, from coastal basins of Brazil, Uruguay and Argentina up to 1200 m a.s.l. Taxonomic divisions within this group were tested using three different species delimitation methods, which found the two existing names to be synonyms and revealed a new cryptic species. Jenynsia darwini sp. nov. is distinguished from all congeners by having a unique combination of character states, including the shape of the dorsal postcleithrum (three times higher than wide v. less than two times higher than wide) and female colour pattern in the half of the caudal peduncle with rows of chromatophores segmented in unaligned spots (v. aligned spots forming lines). The new species also differs from J. lineata by having 26 nucleotide substitutions in the mitochondrial gene cytochrome c oxidase I (coI). Phylogenetic analysis of the genus based on morphological characters proposed by previous studies corroborates monophyly of the subgenera Plesiojenynsia and Jenynsia, with the new species being allocated to the subgenus Jenynsia as the sister group of J. lineata.

A new cryptic species of Hyphessobrycon Durbin, 1908 (Characiformes, Characidae) from the Eastern Amazon, revealed by integrative taxonomy

“…Currently molecular techniques are frequently useful for solve species complexes and discover cryptic species (e.g. Bickford et al 2006;Costa and Amorim 2011;Pereira et al 2011;Adams et al 2014;Costa-Silva 2015;Costa et al 2012Costa et al , 2014Costa et al , 2017Amorim 2018;Guimarães et al 2018;Ottoni et al 2019) and could be an excellent complement for traditional taxonomy (Kekkonen and Hebert 2014). DNA barcoding has demonstrated to be very efficient for delimiting species of Hyphessobrycon, mainly in groups with little morphological variation (i.e., cryptic species) (see Castro-Paz et al 2014;Guimarães et al 2018), preferably when applied together with other species delimitation methods, such as PAA, DBC, CBB, bPTP, and WP in an integrative taxonomy perspective (Guimarães et al 2018).…”

Multigene phylogeny supports diversification of four-eyed fishes and one-sided livebearers (Cyprinodontiformes: Anablepidae) related to major South American geological events

“…The family Anablepidae is a group of cyprinodontiform fishes comprising three recent genera, Anableps Scopoli, 1777, Jenynsia Günther, 1866 and Oxyzygonectes Fowler, 1916, commonly known as four-eyed fishes, one-sided livebearers, and white-eye, respectively [ 1 ]. Two species of Jenynsia and all those included in Anableps and Oxyzygonectes live in coastal salt-water or brackish-water habitats, whereas the remaining 12 species of Jenynsia inhabit freshwaters [ 2 , 3 , 4 , 5 , 6 ].…”

“…The geographical distribution of Anablepidae is restricted to Neotropical areas ( Fig 1 ): Oxyzygonectes is a monotypic genus found in the Pacific coast of Central America; Anableps comprises three species inhabiting both the Pacific coast of Central America and the Atlantic coast of northern South America; and Jenynsia , the most species diverse genus of Anablepidae, comprising 14 species inhabiting the Paraná-Paraguay river system and coastal drainages of south-eastern South America [ 2 , 4 , 21 ]. However, biogeographical historical events responsible for the present distribution of the Anablepidae were never deeply explored [ 2 ].…”

First record sheds light on the distribution of the cyprinodontiform genus Jenynsia (Günther, 1866) in the High Andean Plateau

“…The specimens were kept alive, later anaesthetized with benzocaine and killed by immersion in cold water (0 C) in situ (Metcalfe & Craig, 2011). Then they were fixed in 10% formalin and preserved in 75% ethanol in the Ichthyological Collection of the (Aguilera et al, 2013;Amorim, 2018;Buti & Miquelarena, 1995;Frota et al, 2019;Ghedotti, 2003;Menni et al, 2005, and references therein). The distribution of J. obscura encompasses many endorrheic riverine wetlands associated with the easternmost Sierras Pampeanas ranges at the Cruz del Eje River (type locality, 470 m) and the Conlara River (675 m) to the south.…”