title: A new genus and species of Leptocheliidae (Crustacea: Peracarida: Tanaidacea) from Isla del Coco (Costa Rica).
abstract: Samples from the scarcely-studied sedimentary seabed from the Isla del Coco (Costa Rica) yielded a single species of Tanaidacea, belonging to a new genus of Leptocheliidae, Cocotanais. The new genus shows affinities with Pseudonototanais and Heterotanais in bearing a conspicuous forcipate cheliped in the males, which in Cocotanais has a modified merus and carpal flange. Other distinct characters of the males are a triangular cephalothorax, a three-articled antennular peduncle and swollen bases of pereopods 4-6. Females have a four-articled antennule, a maxilliped endite with three distal flat spines and two inner coupling hooks, and a maxilliped basis with two long setae. The species was found in sheltered bays, both free-living in the sediment and also as a commensal of anemones (Infraorder Boloceroidaria), thus representing the first reported case of such an association.
authors.affiliation: Departamento de Ecología y Biología Animal. Universidad de Vigo. Campus As Lagoas-Marcosende. E-36310 Vigo, Pontevedra, Spain; Email: pesquete@uvigo.es.
authors.forename: Patricia
authors.initials: P
authors.lastname: Esquete
authors.affiliation: Departamento de Ecología y Biología Animal. Universidad de Vigo. Campus As Lagoas-Marcosende. E-36310 Vigo, Pontevedra, Spain Escuela de Biología y Centro de Investigación en Ciencias del Mar y Limnología (CIMAR), Universidad de Costa Rica, San José, Costa Rica.; Email: jeffro.alejandro@gmail.com.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Sibaja-Cordero
authors.affiliation: Departamento de Ecología y Biología Animal. Universidad de Vigo. Campus As Lagoas-Marcosende. E-36310 Vigo, Pontevedra, Spain; Email: troncoso@uvigo.es.
authors.forename: Jesús S
authors.initials: JS
authors.lastname: Troncoso
mesh_terms: D000818:Animals; D003364:Costa Rica; D003445:Crustacea / Q000033:anatomy & histology / Q000145:classification*; D004463:Ecology; D017753:Ecosystem; D005260:Female; D005843:Geography; D008297:Male