A new genus and species of cave-dwelling cyclopine copepod (Copepoda: Cyclopoida) from the Yucatan Peninsula, Mexico

The present study describes a new genus and species of cave dwelling cyclopine cyclopoid copepod based on several adult males and one adult female collected from a cave in the northern Yucatan Peninsula, Mexico. The new genus Aktuncyclops gen. n. has morphological affinities with Bryocyclops, Haplocyclops and Rybocyclops, mainly in the structure and armature of the mouthparts, swimming legs 1–4 and reduction of legs 5 and 6. The new genus has affinities with Bryocyclops s. str. particularly with Group V, with reduced armature and segmentation of swimming legs 1–4, mainly of the spine formula (2,2,2,2) and the structure of intercoxal sclerites. The new genus also diverges from the current generic definition of Rybocyclops and Haplocyclops, both Bryocyclops-stemmed genera; and based on our comparative analysis, the erection of the new genus Aktuncyclops to accommodate these stygobitic cyclopine copepods from Yucatan is justified by its generic characters, such as all bisegmented swimming legs, male A1 14-segmented, geniculated at segment 12, with segment 9 widely expanded, female A1 11-segmented and crescentic anal operculum. The finding of this micro-endemic taxon from the Yucatan Peninsula underscores the need to expand the speleological research in this area and improve the protection strategies for this unique aquatic fauna.http://www.zoobank.org/urn:lsid:zoobank.org:pub:CCF32CB9-2EB0-45A4-B118-95C354D34C45