Hysterothylacium incurvum (Rudolphi, 1819) Deardorff & Overstreet 1981

• Main Authors: Arai, Hisao P., Smith, John W.
• Format: Text
• Language: unknown
• Published: Zenodo 2016
• Subjects: Biodiversity; Taxonomy; Animalia; Nematoda; Secernentea; Ascaridida; Ascarididae; Hysterothylacium; Hysterothylacium incurvum; Canada; Deardorff; Hurley; Northwest Atlantic
• Online Access: https://dx.doi.org/10.5281/zenodo.5626930; https://zenodo.org/record/5626930

Hysterothylacium incurvum (Rudolphi, 1819) Deardorff & Overstreet, 1981 Synonyms: Thynnascaris incurva (Rudolphi, 1819) Dollfus, 1935; Contracaecum incurvum (Rudolphi, 1819) Baylis & Daubney, 1922 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. Lateral alae bifurcate at their tips throughout worm. Cervical alae not flaring. Lips approximately equal in size, all wider than long; flanges widest near base, indented at anterior 1/3. Pulp conspicuously narrow near base. Interlabia with height two times greater than width at base, with rounded tips. Interlabial grooves deep, adjacent grooves nearly merging at base of each lip (Fig. 82 A). Preventriculus clavate, 7–16% of body length. Ventriculus narrower than widest level of preventriculus. Nerve ring located between anterior 7–19% of preventriculus. Excretory pore immediately posterior to nerve ring level. Tail gradually tapering, usually without spines. Males: body 17–34 long by 0.606–0.772 wide. Preventriculus 2.3–5.2, ventriculus 0.117–0.166, ventricular appendix 1.7–2.6, and intestinal caecum 1.9–4.5 long. Spicules 2.6–8.7 long, equal in eight specimens, left one longer in two specimens: spicule ratio 1:0.9–1.0, Caudal papillae 31 to 32 pairs: 27 to 28 pre-cloacal pairs, four post-cloacal pairs, one para-anal papilla, doubled. Distinct medioventral pre-cloacal organ, papillated. Modified annules on ventral surface, beginning near anus, extending anteriorly 2.0–6.1 (Fig. 82 B). Tail flexed ventrad, without spines. Females: body 25–69 long by 0.5–1.7 wide. Preventriculus 2.6–7.2, ventriculus 0.173–0.362, ventricular appendix 0.6–4.0, and intestinal caecum 1.5–5.1 long. Vulva opening 7.3–35.1 from anterior end. Ovaries rarely extending anteriad to vulva level. Eggs 0.018–0.063 in diameter. Tail usually without spines. Site: stomach Host: Xiphias gladius Distribution: Atlantic Records: Nigrelli 1938; Tibbo et al. 1961; Iles 1971; Hogans et al. 1983 : Published as part of Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, pp. 1-274 in Zootaxa 4185 (1) on pages 143-144, DOI: 10.11646/zootaxa.4185.1.1, http://zenodo.org/record/165530 : {"references": ["Deardorff, T. L. & Overstreet, R. M. (1981) Review of Hysterothylacium and Iheringascaris (both previously = Thynnascaris) (Nematoda: Anisakidae) from the northern Gulf of Mexico. Proceedings of the Biological Society of Washington, 93, 1035 - 1079.", "Nigrelli, R. F. (1938) Parasites of the swordfish, Xiphias gladius Linne. American Museum Novitates No. 996, 16 pp.", "Tibbo, S. N., Day, L. R. & Doucet, W. F. (1961) The swordfish (Xiphias gladius L.), its life history and economic significance in the northwest Atlantic. Fisheries Research Board of Canada Bulletin, No. 130, 47 pp.", "Iles, C. (1971) Fisticula plicatus (Cestoda) and Tristoma spp. (Trematoda) on [sic] swordfish from the northwest Atlantic. Journal of the Fisheries Research Board of Canada, 28, 31 - 34. http: // dx. doi. org / 10.1139 / f 71 - 005", "Hogans, W. E., Brattey, J., Uhazy, L. S. & Hurley, P. C. (1983) Helminth parasites of swordfish (Xiphias gladius L.) from the northwest Atlantic Ocean. Journal of Parasitology, 69, 1178 - 1179. http: // dx. doi. org / 10.2307 / 3280895"]}