Ascarophis sebastodis Olsen, 1952

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 90

Ascarophis sebastodis Olsen, 1952

Description (after Ko 1986). With characteristics of the genus.

Males: 5.1 (3.7–6.4) long, 0.026 (0.020–0.030) wide at nerve ring. Buccal cavity 0.080 (0.070–0.100),

muscular oesophagus 0.282 (0.220–0.377) and glandular oesophagus 2.5 (1.7–2.5) long. Nerve ring 0.117 (0.090–

0.144) from anterior end ( Fig. 56 A). Four pairs pre-cloacal and six pairs post-cloacal papillae. Left spicule 0.135

and right spicule 0.047 (0.036–0.053) long. Tail 0.065 (0.053–0.074) long.

Females: 8.7 (7.1–9.4) long, 0.028 (0.022–0.030) at nerve ring. Buccal cavity 0.086 (0.080–0.090), muscular

oesophagus 0.374 (0.310–0.410) and glandular oesophagus 2.5 (1.8–2.9) long. Nerve ring 0.136 (0.115–0.144)

from anterior end. Vulva 2.2 from posterior end. Tail 0.055 (0.041–0.070) long, ending in small knob ( Fig. 56 B).

Eggs 0.037 (0.036–0.038) x 0.023 (0.019–0.024) with polar plug bearing two filaments ( Fig. 56 C). [For comments on A. sebastodis see below]

Site: intestinal lumen

Hosts: Anoplarchus purpurescens (1); Artedius harringtoni (1); Aulorhynchus flavidus (1); Hemilepidotus hemilepidotus (1); Hexagrammos lagocephalus (1); Microstomus pacificus (3); Myoxocephalus polyacanthocephalus (1); Nautichthys oculofasciatus (1); Oncorhynchus kisutch (1, 4); Oncorhynchus nerka (1); Parophrys vetulus (3); Rhamphocottus richardsonii (1); Sebastes alutus (2); Sebastes borealis (2); Sebastes caurinus (1, 2, 4); Sebastes diploproa (2); Sebastes variegatus (1, 2); Sebastes flavidus (2); Sebastes maliger (2); Sebastes nebulosus (5); Sebastes proriger (2); Sebastes ruberrimus (2); Sebastes variegatus (2); Sebastes zacentrus (2)

Distribution: Pacific

Records: 1. Arai 1969; 2. Sekerak & Arai 1977; 3. Kabata & Whitaker 1984; 4. Ko 1986; 5. Holmes 1990

Figures

FIGURE 56. Ascarophis sebastodis Olsen, 1952. A. male, anterior end, lateral view; B. female, posterior end, lateral view; C. egg showing two polar filaments. (Redrawn from Ko 1986).