A new species of parasitic copepod Nothobomolochus and redescription of Orbitacolax hapalogenyos (Yamaguti and Yamasu, 1959) (Cyclopoida: Bomolochidae) off Iraq

A new species of bomolochid copepod Nothobomolochus ilhoikimi sp. n., (Cyclopoida), is described based on adult females collected from the gills of hilsa shad Tenualosa ilisha (Hamilton) (Actinopterygii, Clupeidae) captured in waters off Iraq. The new species differs from its congeners by having the following combination of characters in the adult female: 1) anal somite not spinulate; 2) paragnath blunt and robust; 3) maxilla with slender proximal segment and distal segment with 2 accessory processes terminally; 4) the distal exopodal segment of leg 1 with 3 small spines; and 5) the terminal endopodal segment of leg 4 carrying one long and one short spine. It closely resembles N. triceros (Bassett-Smith, 1898) but prominently differs in above features and also in host specificity. In addition, another bomolochid Orbitacolax hapalogenyos (Yamaguti and Yamasu, 1959) is redescribed based on material collected from Japanese threadfin bream Nemipterus japonicus (Bloch) (Perciformes, Nemipteridae) captured in waters off Iraq. Two species clusters, the hapalogenyos and the analogus groups are recognized in this genus.