Benz G.W., Nagasawa K., Yamaguchi A., McMeans B.C., McElwain A. 2006. New host and ocean records for Driocephalus cerebrinoxius (Sphyriidae, Siphonostomatoida) and a reconsideration of phylogeny within Sphyriidae. Acta Ichthyol. Piscat. 36 (1): 1-9.
Background. Driocephalus cerebrinoxius is an unusual representative of an unusual family of parasitic copepods (Sphyriidae, Siphonostomatoida, Copepoda). This report documents new host and ocean records for D. cerebrinoxius and considers the phylogenetic relationships amongst sphyriid (Sphyriidae) genera.
Materials and methods. Copepods collected from trawl-caught fishes were studied using light microscopy and standard staining, manipulation, and measuring techniques. The phylogenetic analysis (parsimony outgroup analysis) was conducted using adult female morphological characteristics of sphyriid genera.
Results. Driocephalus cerebrinoxius is reported for the first time from the Pacific Ocean and from the star-spotted smooth hound, Mustelus manazo (Triakidae, Carcharhiniformes). The cladistic analysis of sphyriid taxa resulted in 12 shortest trees, each with a length of 16 and consistency index of 0.875. Strict and majority rule consensus trees are presented.
Conclusion. Due to the paucity of morphological characters available for analysis, a robust phylogenetic hypothesis for taxa comprising Sphyriidae is best sought using molecular tools. Without a robust phylogeny it is premature to undertake associated analyses regarding historical ecology within Sphyriidae.
Keywords: parasitic copepods, Sphyriidae, Siphonostomatoida, mesoparasites, shark parasites, fish parasites, phylogeny