Telestacicold xenophiothricis n. sp (Copepoda, Poecilostomatoida), a remarkably well adapted commensal of the brittlestar Ophiothrix purpurea (Echinodermata)

A study of the turbellarian commensal fauna of the brittlestar Ophiothrix purpurea in Hansa Bay (Papua New Guinea) revealed the presence of a remarkably well-adapted lichomolgid copepod : Telestacicola xenophiothricis n. sp. (Rynchomolgidae, Poecilostomatoida). Fourteen out of 118 (12\%) ophiuroids inspected were infested by one to three copepods (a total of 18 specimens observed). The body colour of this commensal crustacean mimics perfectly the pattern of orange-red and pink lines of the central disk of the host, and this complex and uncommon mimicry could indicate a high host specificity. T xenophiothricis is the fourth member in this genus, but is the first encountered on ophiuroids (Echinodermata), while it is the tenth species of Poecilostomatoida amongst the 46 known species of Copepoda associated with ophiuroids (others are 22 Siphonostomatoida, 13 Cyclopoida and one Harpacticoida). Furthermore, the generic assignment of Doridicola claudus Humes & Stock is discussed, and the species is allocated to the genus Telestacicola.