No abstract

No abstract

No abstract

(1) Background: Integrative taxonomy has been important in the comprehension of relationships among nematode parasites. Philometridae is a highly diverse family of these organisms, but poorly-known regarding genetic characterization and evolution. An integrative taxonomic analysis was performed to improve the knowledge of the evolutionary history of Philometridae. (2) Methods: Phylogenies were reconstructed based on genetic sequences alone and integrated with morphological/life history traits, which were phylogenetically mapped. The host–parasite cophylogeny was evaluated. (3) Results: Previously unpublished 28S rDNA sequences are given for some species. The phylogeny from this marker, although limited by data scarcity, showed similar patterns as that from 18S rDNA. Clades shared common features related to the structure of the esophagus and of the tail in males (especially the gubernaculum), site of infection, habitat, host taxa and geographic origin; most of these features were phylogenetically informative. The integrative phylogeny was better resolved. A cophylogenetic signal was present mainly in clades of freshwater species. (4) Conclusions: The speciation process in Philometridae is not unique or uniform; host capture, host–parasite co-evolution and allopatric (especially in freshwater) events may be occurring simultaneously in different lineages, places and times. Cases of plesiomorphy retention probably occur. Evolutionary convergence of poorly-informative characters is suggested, even though they are important for species diagnosis.

Two new species of parasitic copepods of the genus Colobomatus Hesse, 1873 (Cyclopoida) are proposed based on specimens collected from the squirrelfishes (Holocentridae) off the coast of Rio de Janeiro, Brazil. Colobomatus luquei n. sp. from the interorbital canals of Holocentrus adscensionis (Osbeck) can be distinguished from its closest congeners by the following combination of characters in the adult female: first to fourth thoracic somites fused, two pairs of thoracic processes, fifth pedigerous somite without processes, and process in the third abdominal somite not transpassing the margins of the caudal rami; and in the adult male: antenna with two elements in the second endopodal segment, leg 1 with three spines and three setae in the second endopodal segment, and leg 2 with three spines and three setae in the second exopodal segment. Colobomatus freirei n. sp. from the interorbital canals of Holocentrus rufus (Walbaum) can be distinguished from its closest congeners through the possession of an anterior pair of thoracic processes four times longer than the posterior pair. The two new species described herein are the first representatives of the family Philichthyidae found to parasitize fish of the order Holocentriformes.