Phylogeny, diversity, and species delimitation of the North American Round-Nosed Minnows (Teleostei: Dionda), as inferred from mitochondrial and nuclear DNA sequences

Morphological and Genetic Evidence for Multiple Evolutionary Distinct Lineages in the Endangered and Commercially Exploited Red Lined Torpedo Barbs Endemic to the Western Ghats of India

“…The Palghat gap has been suggested as a biogeographic barrier [5], which has separated species and/or genetic lineages of several taxa including plants [44], amphibians [45], [46], birds [47] and elephant [48]. Our findings support previous studies and indicate that this biogeographic barrier might have played an important role in the distribution of freshwater fishes.…”

“…Accelerating the description of unknown biodiversity continues to be a major challenge as extinction rates increase [2] and modern taxonomy is far from reaching a scientific consensus on species concept and delimitation [3], [4]. As a result, distinctive units, such as evolutionarily significant units (ESUs) or designatable units (DUs), which are appropriate targets for conservation, may remain undetected for long periods of time [5]. This is a critical impediment particularly for regions harboring exceptionally high biodiversity, that face a high risk of anthropogenic impacts [6] and also among speciose yet poorly known taxa, such as reptiles [7]–[9] and freshwater fishes [10]–[13].…”

Conservation Genetics of Six Species of GenusDionda(Cyprinidae) in the Southwestern United States

“…Fish and Wildlife Service (USFWS), we evaluated the conservation-genetic status of 10 populations representing 6 species of roundnose minnows (Cyprinidae: genus Dionda) from spring-fed headwaters in Texas and New Mexico. Species of Dionda are found in the southwestern United States and Mexico; 7 nominal and 2 undescribed species occur in central and west Texas; 1 nominal and 1 undescribed species occur in New Mexico; and 3 nominal and 2 undescribed species occur in Mexico (Schönhuth et al 2012. Roundnose minnows typically inhabit springs and spring-fed streams (Hubbs and Brown 1956, Hubbs et al 1991, Edwards et al 2004 and are of particular interest to conservation and management by TPWD and USFWS, in part because of their limited distribution in springfed headwaters, and in part as indicator species of habitat quality (Harvey 2005, Edwards et al 2004).…”

“…serena,and D. texensis (until recently,D. serena from the Nueces River). The recent taxonomic revisions may be found in Schönhuth et al (2012). Dionda diaboli is considered threatened by both the United States and the state of Texas (USFWS 1999) and endangered by the Endangered Species Committee of the American Fisheries Society (Jelks et al 2008).…”

“…The federal recovery action plan (USFWS 2005) for D. diaboli includes evaluation of geographic variation and population genetic structure. Scharpf (2005) listed both D. argentosa and D. serena (the latter was split into D. serena and D. texensis by Schönhuth et al 2012) as imperiled, whereas D. episcopa and D. flavipinnis (listed then as D. nigrotaeniata) were listed as secure. With support from TPWD and USFWS, we acquired sequences of mitochondrial (mt)DNA and genotypes at nuclear-encoded microsatellites to evaluate the conservation-genetic status of these species.…”