Lappetascaris sp.

Nagasawa, K. & Moravec, F., 2002, Larval anisakid nematodes from four species of squid (Cephalopoda: Teuthoidea) from the central and western North Paci ® c Ocean, Journal of Natural History 36 (8), pp. 883-891 : 889-890

Lappetascaris sp. Type B

(®gure 4)

Third-stage larva (10 specimens). Body whitish, 3360±6350 long and 124±447 in maximum width; maximum width of body at its posterior part. Whole body with conspicuous, large, light-coloured hypodermal cells. Cephalic end narrowed, truncated, with poorly developed anlagen of lips anteriorly provided with transparent cuticular mounds surrounding mouth opening. Ventral part of cephalic end protruding more anteriorly than dorsal one. Anlagen of lips bearing at their outer sides narrow, weakly sclerotized supports exceeding base of lip anlagen posteriorly; posterior parts of these formations appearing as small posterior processes 10±34 long. Oesophagus almost cylindrical, without any anterior inātion, measuring 539±980; anterior half of oesophagus with dorsal oesophageal gland 296±779 long and 20±57 wide. Nerve ring and excretory pore 200±475 and 228±570, respectively, from anterior extremity. Ventriculus elongate-oval, measuring 76±1903 48±152. Posterior ventricular appendix very long, measuring 1590±4570 (47±73% of body length). Intestine straight, light-coloured. Intestinal caecum dorsal, extending anteriorly approximately to level of excretory pore, 620±1120 long. Length ratio of intestinal caecum and ventricular appendix 1:2.3±4.6. Rectum hyaline tube. Three almost spherical unicellular rectal glands present. Tail conical, 100±362 long, with small cuticular spike (6±10) at tip.

Host. Ommastrephe s bartramii (LeSueur, 1821) (fam. Ommastrephidae ).

Site of infection. In capsules on stomach wall.

Localities. Central North Paci®c Ocean (38ss30¾N, 179ss30¾W, 18 June 1993; 25ss29¾±30ss34¾N, 164ss55¾±165ss01¾W, 30 ± 31 May 1992) and western North Paci®c Ocean (41ss30¾N, 145ss30¾E, 31 October 1981).

Voucher specimens deposited. Natural Science Museum, Tokyo ( NSMT, as 2942 to 2943) and Institute of Parasitology, Academy of Sciences of the Czech Republic, C Ïeske BudeÏjovice (Cat. No. N-704).

Comments

Larvae of this type are morphologically very similar to those of Lappetascaris sp. Type A, but diOEer from them mainly in the body length (3±7 mm) and in the site of localization (encapsulated on stomach wall) in the squid. It is not known whether they belong to another Lappetascaris species or whether they undergo further development and migration within the squid, and are conspeci®c with Type A larvae. Apparently, larvae identical with Lappetascaris sp. Type B (reported as Hysterothylacium sp. ) have already been found by Bower and Margolis (1991) from capsules on the stomach wall and gonads of the ¯ying squid, Ommastrephe s bartramii , in the eastern North Paci®c waters; larvae of this type (2±8 mm long) represented the majority (96%) of the Hysterothylacium (5 Lappetascaris ) sp. found in squid.

In the present material, the capsules with Lappetascaris sp. Type B usually contained a large number of these larvae (about 50±60 per capsule).