Dr. Éva Murai szerk.: Miscellanea Zoologica Hungarica 1. 1982 (Budapest, 1982)
Sey, O.: The morphology, life-cycle and geographical distribution of Paramphistomum cervi (Zeder, 1790) (Trematoda: Paramphistomata)
Alces alces, Bison bonasus, Bos taurus , Bos grunniens , Bubalus bubalis, Capra hircus , Capreolus capreolus, Cervus elaphus , Cervus nippon , Dama dama, Ovis aries , Ovis musimon and Rangifer tarandus. LIFE-CYCLE EXAMINATIONS Under the name of P. cervi and in the sense of the scope of P. cervi presented in this paper, information on the whole process or certain stages of its life-cycle was published by LOOSS (1896), NÖLLER & SCHMIDT (1924), TAKAHASHI (1927), KRULL (1933), SZIDAT (1936), WILLMOTT (1952), DADURYAN (1953), WILLMOTT & PESTER (1955), KRYUKOVA (1957), GRETILLAT (1958), ABDEL-GHANI (1961), POGORELYI & MEREMINSKII (1963), BORTNOVSKH (1964), NIKITIN (1967, 1968), GLUZMAN (1969), KRANEBURG (1977), KRANEBURG & BOCH (1978), ODENING et al. (1978) and ODENING et al. (1979). On the basis of personal examinations and literary data, the life-cycle of P. cervi is summarized as follows. Preparasitic stages Eggs and embryonic development Eggs of P. cervi are greenish yellow, covered by colourless shell. Their shape may be piriform, oval or elliptical. The antiopercular pole bears a minute spine. Measurement of eggs are 116-189 by 52-116 jjm. Variations of egg size could be observed not only among the eggs laid by a worm population but also among those of separate specimens. No direct correlation appears to exist between the body dimension of the fluke and that of the eggs. Newly laid eggs contain zygote situated near to the opercular end of the egg and during the subsequent divisions it moves towards the centre of it and becomes surrounded by vitelline cells. During incubation at 27 C no significant change can be observed in the first 4-5 days except for the growth of the embryo. On the 5-6th days, the terebratorium, the single apical as well as the four penetrating glands appear. On the 7th day the flame cells, found by the joining of the second-third epidermal cell rows, begin their activity. The formation of the germinal tissue also takes place during this period. With the growth of the embryo, the vitelline cells gradually decrease and their place is occupied by two large vacuoles. Mucoid plug is not observable (Fig. 7). On the 8th and 10th days, the embryo reaches a size of 110-145 jum and the embryo (miracidium) is ready for hatching. Under controlled temperature (27 C) hatching of miracidia usually begins on the 8th day, and it continues on the following two-four days. After the optimal period of hatchability (10th day) the life span of the embryos is much shorter than that of P . daubneyi (SEY, 1979a). The eggs maintain vitality, under low temperature (4-6°C) for 5-6 months, suggesting the possibility of hibernation In the temperate belt. Figs. 1-6. Median sagittal sections of pharynx (1: Paramphistonum cervi, Näsmark's material) and genital openings (2: P. cervi, Näsmark's material; 3: P. cervi, own material; 4: P. gotoi Iraqi material; 5-6: P. garcile and P. epiclitum, Indian material; Figs. 2-6 were taken with the same magnification) Figs. 7-13. Stages of development of P. cervi - 7: egg with fully developed miracidium; 8: living miracidium; 9: epidermal cells of miracidium; 10: four-day-old sporocyst; 11: mature redia with young cercariae, one of them bears eye spots; 12: mature cercaria; 13: encysted metacercariae on aquatic plant Figs. 14-18. Median sagittal sections of pharynxes (14: P. gotoi, Iraqi material; 15: P. liorchis, Näsmark's material; 16: P. cervi, own material) and genital openings (17-18: P. liorchis, Natterer' s material from Vienna Museum) (Photo by O. SEY)
