TL;DR: Examination of morphological variation across the range of these forms, and diagnosed and mapped the distributions of valid species, recognized in Acanthocobitis and the recently recognized Paracanthcobitis, finds five newly described species and two removed from synonymy.
Abstract: Acanthocobitis was created by Peters in 1861 for a new species, A. longipinnis, from the Ganges River basin in India and has been treated over the past 150 years as a valid genus or as a synonym of Nemacheilus or Noemacheilus. A large number of names have been proposed for species that are morphologically similar, and presumably closely related, to A. longipinnis, with eight treated in recent publications as valid species (most with poorly understood geographic distributions), and 15 treated as synonyms. The present study examined morphological variation across the range of these forms, and diagnosed and mapped the distributions of valid species. Fifteen species are recognized in Acanthocobitis and the recently recognized Paracanthocobitis, including five newly described species and two removed from synonymy. Acanthocobitis is known from the Ganges and Brahmaputra basins of northern India and Bangladesh. Paracanthocobitis ranges from the Indus basin in Pakistan to the Mekong basin of Cambodia and Laos. A ...
TL;DR: A higher diversity within the P. zonalternans species complex than formerly believed is document and a strong impact of global sea level on its evolutionary history is reported, which can be expected in all stationary fauna in all non-mountainous coastal regions worldwide.