Orbitacolax williamsi Cressey & Cressey, 1989

Soler-Jimenez, Lilia C., Morales-Serna, F. Neptali, Aguirre-Macedo, Ma. Leopoldina, McLaughlin, John P., Jaramillo, Alejandra G., Shaw, Jenny C., James, Anna K., Hechinger, Ryan F., Kuris, Armand M., Lafferty, Kevin D. & Vidal-Martinez, Victor M., 2019, Parasitic copepods (Crustacea, Hexanauplia) on fishes from the lagoon flats of Palmyra Atoll, Central Pacific, ZooKeys 833, pp. 85-106 : 85

Orbitacolax williamsi Cressey & Cressey, 1989

Type host.

Scolopsis taenioptera (as S. dubiosus ) (Cuvier) ( Nemipteridae ).

Other host and localities.

Scolopsis taenioptera (as S. dubiosus ) from Okinawa, Japan ( Cressey and Cressey 1989). Coris batuensis (Bleeker) ( Labridae ) from Lizard Island, Australia ( Muñoz and Cribb 2006). Thamnaconus degeni (Regan) ( Monacanthidae ) from South Australia ( Hayward et al. 2011).

Current host.

Mulloidichthys flavolineatus ( Mullidae ).

Site of infection.

Gills.

Prevalence and mean intensity.

1.9 and 1 (n = 52).

Specimens deposited.

CHCM No. 560 (voucher) (1 vial, 1 specimen ♀).

Remarks.

To date, the genus Orbitacolax includes 10 valid species, which form two clusters ( Venmathi Maran et al. 2014), the hapalogenyos -group with four species ( O. hapalogenyos , O. pteragogi , O. trichiuri , and O. unguifer ) and analogus -group with six species ( O. analogus , O. dactylopterusi , O. aculeatus , O. leptoscari , O. uniunquis , and O. williamsi ). This second group is based on the second endopodal segment of leg 2 either no inner seta or having 1 inner seta. Particularly, O. williamsi lacks seta on the second endopodal segment of leg 2, as seen in our specimen and the original description provided by Cressey and Cressey (1989). However, Venmathi-Maran et al. (2014) pointed out that O. williamsi carries 1 inner seta in that segment, but this is likely inaccurate. Orbitacolax williamsi has been found on western Pacific fishes from four families, suggesting that this parasite may have a low host specificity.