title: Sea lice (Siphonostomatoida: Caligidae) diversity on littoral fishes from the south-eastern Pacific coast determined from morphology and molecular analysis, with description of a new species (Lepeophtheirus confusum).
abstract: Parasitic copepods of the family Caligidae are common on marine fish worldwide, and some species are responsible for disease outbreaks in aquaculture. Ten species of Lepeophtheirus have thus far been described in the south-eastern Pacific coast. Seven species have been recorded from littoral fish species. However, the latitudinal distribution and host ranges of these Lepeophtheirus spp. are not known. We evaluated, using morphology and molecular analyses, the taxonomic diversity, geographical distributions and host range of known Lepeophtheirus species. Seventeen fish species were examined for copepods. The collected parasites were identified according to their morphology and genetic sequences, based on rDNA 28S and COI genes. The recognition of Lepeophtheirus chilensis and L. mugiloides was indeed difficult due to the high morphological similarities between them. However, their taxonomic statuses were supported by the COI gene and ABGD analysis, with 6% of genetic distance. Moreover, a new species with a genetic distance of 19-22% with respect to known species was detected and described herein as L. confusum. This new species can be distinguished from other Lepeophtheirus spp. by a combination of characters (maxillary tine length and width; furca shape; the fifth leg position, shape and armature; maxillule tine length and thickness; and maxilliped armature on the myxal area). Lepeophtheirus chilensis, L. mugiloides and L. frecuens co-occurred on several littoral fish species, showing an extensive latitudinal distribution, whereas L. confusum was found only on Eleginops maclovinus from southern latitudes.
authors: Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile. Electronic address: teresa.gonzalez@uantof.cl.
authors: M Teresa
authors: MT
authors: González
authors: Depto. Ciencias Acuáticas y Ambientales, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile.
authors: Raúl
authors: R
authors: Castro
authors: Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, P.O. 5080, Viña del Mar, Chile.
authors: Gabriela
authors: G
authors: Muñoz
authors: Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile.
authors: Zambra
authors: Z
authors: López
mesh_terms: D000818:Animals; D033342:Copepoda / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D005393:Fish Diseases / Q000469:parasitology*; D005843:Geography; D058507:Host Specificity; D058889:Molecular Typing; D010140:Pacific Ocean; D010473:Perciformes / Q000469:parasitology*; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics
chemical_list: D012339:RNA, Ribosomal, 28S; D003576:Electron Transport Complex IV
keywords: ABGD analysis; COI gene; Chile, host range; Copepods, 28S gene