A new Leptodiaptomus (Copepoda: Calanoida: Diaptomidae) from Jalisco, Mexico, with a key to species and comments on species groups

The freshwater calanoid copepod genus Leptodiaptomus Light, contains roughly 20 species, eight of which have been reported in Mexico. Male and female individuals of an undescribed species of this genus were collected during a plankton survey of a small temporary pond in the state of Jalisco, Mexico. The new species is described from adult male and female individuals and was assigned to Leptodiaptomus based on the armature of the male right antennule, the structure of the male right fifth leg, and the reduced third exopod of the female fifth legs. Leptodiaptomus amulensis sp. n. closely resembles L. signicauda, but can easily be distinguished by the shape of the female genital somite, the shape of the male right fifth leg endopod, the non-articulated coxal projections of the female fifth legs, and the presence of spinules on the coxae of both male and female fifth legs. To perform a complete comparative analysis, the type specimens of 20 species of North American Leptodiaptomus deposited in the National Museum of Natural History were examined. The new species L. amulensis has been found so far only in its type locality, with a very limited distribution, as also observed for some of its congeners.http://www.zoobank.org/urn:lsid:zoobank.org:pub:D1C632A6-4549-4F0F-ABA2-4411F2403D6A