Morfología, diversidad y distribución de los Cyclopoida (Copepoda) de zonas áridas del centro-norte de México. I. Cyclopinae

freshwater cyclopoid copepods represent a group whose diversity and biogeography has been studied in different areas of mexico, but its knowledge in arid environments, mainly in the central-northern region of the country, was still limited. from samples previously obtained (1985-2008) and also from new collections, we reviewed the copepod of the subfamily cyclopinae from water bodies of this extense arid zone of mexico. this study incorporated three priority eco-regions (conabio), that include the states of aguascalientes, zacatecas, san luis potosí, durango, chihuahua and coahuila. up to 16 species of the subfamily cyclopinae were found, including 3 undescribed species (one acanthocyclops, two microcyclops) and other species that are probable endemics in this region of the country. the genus metacyclops is recorded for the first time in mexico. diagnoses and taxonomic illustrations of the species are provided together with a comparative analysis of the specimens examined. up to 22 new state records of cyclopines are presented; this is also the first taxonomic survey on freshwater copepods focused in this arid area of mexico. with the findings reported here the number of species of cyclopinae occurring in mexico increased from 37 to 43 (16%).