Expanding territories: new host records and four new species of herpyllobiid parasitic copepods (Copepoda: Herpyllobiidae) from Papua New Guinea deep-water polynoid polychaetes (Annelida: Polynoidae)

The parasitological examination of polynoid polychaetes collected in deep water substrates (333-780 m) off Papua New Guinea allowed us to detect four infected specimens, including two new annelid host species (Harmothoe samadiae sp. n., Eunoe corbariae sp. n.), Lepidasthenia brunnea sensu Knox, and Harmothoe sp. Three of the parasites were identified as members of the mesoparasitic copepod genus Herpyllobius Steenstrup and L & uuml;tken, and one of Gottoniella L & oacute;pez-Gonz & aacute;lez, Bresciani and Conradi, (Herpyllobiidae). Herpyllobius chambardi sp. n., found on L. brunnea, is distinguished from its congeneric species by having a longitudinal constriction dividing its globose ectosoma into two symmetrical hemispheres. The second species, H. hourdezi sp. n., on H. samadiae, shows a depressed intergenital margin, lacks sclerotised dots, and exhibits a large endosoma with several thick lobes. Herpyllobius pabloi sp. n., found on E. corbariae, closely resembles its congeneric species H. polynoes, but differs in the endosomal structure and details of the ectosoma. Herpyllobius species are known to infect at least 14 polynoid genera, to which we can now add Lepidasthenia Malmgren, thus expanding its host range among polynoids. These three Papuan species are additional new records of this chiefly cold-temperate copepod genus to be reported from subtropical latitudes. The discovery of Herpyllobius parasitising a species of Harmothoe confirms its preference for infecting this polynoid genus. The new Gottoniella, also on Harmothoe sp. is the third known species of the genus; it has heavily sclerotised genital swellings, slit-like genital openings, a distinctive fin-like lateral ectosomal process, a short, sclerotised ring, and a pipe-like stalk connecting the endosoma. Both H. chambardi and H. hourdezi are among the deep-living members of Herpyllobius in the Southern Hemisphere, the latter representing the deepest record of the genus (780 m) worldwide. http://www.zoobank.org/urn:lsid:zoobank.org:pub:06F549E4-0B02-4EC8-991C-A9937AAE2AA2