Description of Colobomatus conodoni n. sp. (Cyclopoida: Philichthyidae), a New Parasitic Copepod from the Barred Grunt Conodon nobilis (Linnaeus, 1758) (Actinopterygii: Haemulidae) Off the Brazilian Coast

Introduction

Copepods of the genus Colobomatus Hesse, 1873 are parasites associated with subcutaneous spaces of marine fish. To date, around 76 species of the genus have been described in marine ecosystems, but few species have been recorded in the South Atlantic Ocean.

Methods

One hundred and eight specimens of Co. nobilis were purchased along the littoral of Brazil. The copepods were collected from the skull bones associated to the nasal cavities, fixed and preserved in 80% ethanol and for microscopical observation, specimens were cleared in 85% lactic acid. Drawings were made with the aid of an Olympus BX51 microscope equipped with a drawing tube.

Results

Colobomatus conodoni n. sp. can be distinguished from all congeners by the combination of the following characters: (i) two cephalic processes that are longer than the cephalosome, (ii) third abdominal somite with a pair of processes, (iii) caudal rami forked at the tip.

Conclusion

This is the first representative of the family Philichthyidae Vogt, 1877 described parasitizing a species of the teleost genus Conodon Cuvier. Together with the new species, the number of philichthyid species in the South Atlantic Ocean increases to 12 and extends the list of Colobomatus spp. to 77.