Pulchrascaris chiloscyllii (Johnston & Mawson, 1951) Deardorff, 1987

Gonzalez-Solis, David, Soler-Jimenez, Lilia C., Aguirre-Macedo, M. Leopoldina, McLaughlin, John P., Shaw, Jenny C., James, Anna K., Hechinger, Ryan F., Kuris, Armand M., Lafferty, Kevin D. & Vidal-Martinez, Victor M., 2019, Parasitic nematodes of marine fishes from Palmyra Atoll, East Indo-Pacific, including a new species of Spinitectus (Nematoda, Cystidicolidae), ZooKeys 892, pp. 1-26 : 1

Pulchrascaris chiloscyllii (Johnston & Mawson, 1951) Deardorff, 1987

Description.

Male (1 mature specimen, measurements of one young specimen in parenthesis): elongate, relatively large nematodes, 68.01 (20.36) mm long, 767 (388) wide. Cuticular alae distinct. Lips small, greatly reduced, with tooth-like structures. Nerve ring located at first third of esophagus length, 503 (380); deirids posterior to level of nerve ring, 604, both from anterior body end. Excretory pore between base of subventral lips. Esophagus cylindrical, 2.96 (1.95) mm long, with large ventriculus at posterior end, 3.38 (2.12) mm long, and without ventricular appendage. Intestinal caecum anteriorly directed, somewhat larger than ventriculus, 3.57 (2.36) mm long. Spicules equal, similar, alate, 1.48 mm long; gubernaculum absent. Caudal papillae 51 pairs: 42 precloals pairs (some subventral and other sublateral), 4 adcloacal subventral pairs, 5 postcloacal (including phasmids). One single, ventral papilla on the anterior cloacal lip. Three cuticular plates immediately posterior to cloacal opening, with serrate edges. Tail conical, short, 298 (182) long.

Fourth-stage larva (1 specimen): Length of body 11.56 mm long, 233 wide. Esophagus, ventriculus and intestinal caecum 1.25, 0.93, 1.08 mm, respectively. Nerve ring 275, deirids 355, both from the cephalic end. Tail 126 long.

Host.

Carcharhinus melanopterus (Quoy & Gaimard) ( Carcharhinidae ).

Site of infection.

Intestine.

Prevalence and mean intensity.

80 and 35 ± 26.5 (n = 5).

Specimens deposited.

CHCM no. 619 (voucher) (1 vial, 1 specimen ♀).

Remarks.

These specimens are morphologically similar to P. chiloscyllii (reported as Terranova chiloscyllii ), originally found in Chiloscyllium punctatum Müller & Henle and Mustelus antarcticus Günther (reported as Emissola antarctica ) from the Central Queensland coast ( Johnston and Mawson 1951). This species was redescribed by Deardorff (1987) from Sphyrna lewini (Griffith) and Sphyrna zygaena (Linnaeus) ( Sphyrnidae ) off Hawaii, Alabama and South Africa, and later recorded in Trianenodon obesus ( Rüppell) ( Carcharhinidae ) and C. melanopterus from the Solomon Islands and the Maldives by Bruce and Cannon (1990). Our specimens are somewhat larger than those described earlier, but this difference is consistent with intraspecific variability.