Hysterothylacium corrugatum Deardorff & Overstreet, 1981

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 141-142

Hysterothylacium corrugatum Deardorff & Overstreet, 1981

Description (after Deardorff & Overstreet 1981). With characteristics of the genus. Body reaching greatest width near midbody. Cuticle with inconspicuous annulations except ventrally on male’s posterior. Cervical alae not flaring. Lips about equal in size, occasionally wider than long; flanges widest near base, indented at anterior 2/5. Pulp for each lip not narrowed at base, each with two to four lobular projections often a few times longer than wide. Interlabia with height equal to or slightly less than width at base, with rounded tips. Interlabial grooves absent ( Fig. 81 A). Preventriculus clavate, 5–13% of body length. Ventriculus narrower than widest level of preventriculus, generally longer than broad; ventricular appendix descending without angulation from posterior portion of ventriculus. Nerve ring located between anterior 6–12% of preventriculus. Excretory pore immediately behind level of nerve ring. Tail gradually tapering, ending without spines.

Males: body 26–50 long by 0.4–1.0 wide. Preventriculus 3.0–5.6, ventriculus 0.036–0.154, ventricular appendix 2.4–3.8, and intestinal caecum 2.3–4.6 long. Spicules similar length: left one 1.2–2.5, right one 1.2–2.6. Caudal papillae 29 to 31 pairs, 24 to 26 pre–cloacal pairs, four post–cloacal pairs, one para-anal pair, doubled. Distinct medioventral pre-cloacal organ, papillated. Modified annules on ventral surface, beginning near anus, extending anteriorly1.0–4.1. Tail flexed ventrad, lacking spines ( Fig. 81 B).

Females: body 100–142 long by 1.7–2.6 wide. Preventriculus 5.5–8.5, ventriculus 0.154–0.472, ventricular appendix 3.5–4.3, and intestinal caecum 5.3–7.2 long. Vulva opening 35 to 40 from anterior end. Ovaries rarely extending anteriad beyond level of vulva. Eggs 0.040–0.080 in diameter. Tail tapered, lacking spines.

Site: stomach

Host: Xiphias gladius Distribution: Atlantic Record: Hogans et al. 1983

Figures

FIGURE 81. Hysterothylacium corrugatum Deardorff & Overstreet, 1981. A. head, lips, dorsal view; B. male, posterior end showing post-cloacal and pre-cloacal papillae, and modified annules. (Redrawn from Deardorff & Overstreet 1981)