VIPERA BERUS AND V-AMMODYTES (SERPENTES, VIPERIDAE) REPRESENT NEW HOSTS FOR CARYOSPORA SIMPLEX (APICOMPLEXA, EIMERIIDAE) IN EUROPE

During a survey of the coccidian parasites of reptiles, caryosporan oo cysts were found in the faeces of wild and captive European viperid sn akes Vipera berus (L.) and V.ammodytes (L.). Thirty two of 37 examined V. berus (86%) and 9 of 17 examined V. ammodytes (53%) specimens were found to be passing caryosporan oocysts. Morphological characters of all caryosporan isolates were identical and fitted well with the descr iption of Caryospora simplex Leger, 1904. Experimental inoculation of severe combined immunodeficient (SCID) mice with seven isolates of C. simplex from V. berus or V. ammodytes confirmed the heteroxenous life cycle pattern, for the first time for isolates of evidently European o rigin. Caryosporan developmental stages were observed in the connectiv e tissues of the nose, cheeks, ear and scrotum in all inoculated SCID mice. V. berus and V. ammodytes represent new hosts for C. simplex. Th e present paper represents the first widely based report on coccidian parasites of the genus Caryospora Leger in European viperids. Our find ings indicate a wide distribution of C. simplex throughout the range o f distribution of snakes of the genus Vipera.