Dr. Éva Murai szerk.: Miscellanea Zoologica Hungarica 1. 1982 (Budapest, 1982)
Murai, É.: Taeniid species in Hungary (Cestoda: Taeniidae). II. Larval stages of taeniids parasitizing rodents and lagomorphs
Rattus norvegicus - County Győr-Sopron: Balf 22/04/71 = 1 case. Characterization of the larval Hydatigera taeniaeformis Strobilocercus fasciolaris is situated always on the liver surface. The host-cysts are yellowish-white, globular to ovoid, about the size of 5-12 mm. In the host-cyst the larva freely coils up, 50-150 mm in length and 1-3 mm in width. The form of strobilocercus characterized by a pseudosegmented body, on the anterior end with a scolex identical to that of the adult worm, on the posterior end with a bladder 2-4 mm in diameter. The scolex is protruded (in the fully developed larva) or invaginated (young larva), 1-1.3 mm in diameter. The rostellum is 0.6, the suckers are 0.56 mm in diameter. Rostellar hooks 30 to 36 in number situated in two circles. Large hooks 0.420-0.456 mm (modal value 0.430 mm), the small ones 0.250-0.288 mm (modal value 0.272 mm) in length. The shape of fully developed hooks illustrated in Figures 30 and 41. In the first report on taeniids in Hungary (MURAI & TENORA, 1973) we noted the presence of two forms of uncertain specific identity ( Cysticercus sp. I, and Cysticercu s sp. II) parasitizing Mus musculus spicilegus and Microtus arvalis. Several forms similar to these have been found in rodents in Afghanistan by TENORA & KULMAN (1969). I have succeeded in finding a number of very young cysticerci in the Taeniidae material collected up to 1980, and I have come to the conclusion that these forms represent nothing but the very earliest developmental stages of Hydatigera taeniaeformis . The youngest forms of Strobilocercus fasciolar is are free-lying cysticerci enclosed in translucent host-cysts, on the surface of the liver, 1-3 mm in diameter. The Cysticercus at this stage is globular, the wall of the bladder possesses a scolex invaginated towards the lumen. Its diameter is 0.3 mm. The 29-36 soft hooks are in the beginning awl-shaped, latter sickle-shaped. At this stage on the rostellum large numbers of acicular very fine and short to punctiform chitinous formations are present, which disappear with the development of the larva. These chitinous formations first seemed to indicate very young hooks and we (MURAI & TENORA, 1973) thought that we were dealing with a Joyeuxiella species, but I exclude this possibility now. Young larvae of H. taeniaeformis have been found in the following number of intermediate hosts: 12 Microtus arvalis , 8 Apodemus flavicollis and 6 Mus musculus spicilegus . The hooks (or hook formations) are arranged in two rows even in the youngest larvae, with those of the outer row being smaller. The shape and size of the hooks vary according to the following scheme: A) Awl-shaped hook formations ( Cysticercus sp. II. in MURAI & TENORA, 1973) - length of large and small hooks in mm, respectively: 0.075 and 0.060, 0.120 and 0.095, 0.160 and 0.136 (Figs 31-33). B) Sickle-shaped hooks ( Cysticercus sp. I. in MURAI & TENORA, 1973): 0.210 and 0.165, 0.235 and 0.128, 0.250 and 0.185 (Figs 34-36). C) Diameter of host-cyst up to 5 mm, with the hooks gradually developing a guard and a handle: 0.310 and 0.210, 0.370 and 0.240, 0.390 and 0.250 in size (Figs 37-40). D) Developed hooks (0.430 and 0.270) were found in cysts at least 8 mm in diameter. The body of the strobilocercus larva is elongated, with well-discernible pseudosegmentation and posterior bladder. The body of the larva continous growing after development of the scolex. The larva of Hydatigera taeniaeformis is the most common taeniid parasite of rodents in Hungary; it occurs equally in microtias and murids. This species was found in all samples which consisted of at least 50 examined small mammals. NECHAY (1973) studied the infestation of Microtus arvalis by H. taeniaeformis in the Fejér, Heves, Nógrád, Pest and Vas counties and found an infestation rate of 7.2%. It occurs in laboratory rodents as well by spontaneous infestation (see MURAI & TENORA, 1973). Massive infestation by H. taeniaeformis may lead to the death of the intermediate host by severely damaging the liver during its invasion (NECHAY, 1973). Developed larvae are apparently indifferent to the host rodents. Data so far indicate that the definitive host of this species are the domestic and the wild cat, which may be severely infested (MURAI & TENORA, 1973, MURAI & SUGÁR, 1976).
