ON THE VARIABILITY OF BRACHYLECITHUM-STRIGOSUM (LOOSS, 1899) (TREMATODA, DICROCOELIIDAE) IN CUCULUS-CANORUS L. (CUCULIFORMES) IN SLOVAKIA

Over 180 dicrocoeliids Brachylecithum strigosum (Looss, 1899) were obt ained from livers of common Eurasian cuckoos, Cuculus canorus L. in ea stern Slovakia. Morphological analysis of 78 worms coming from 7 hosts (7 organophenotes) revealed a remarkably high variation either within digenean intrapopulation communities coming from various host individ uals and among them. Generally, B. strigosum specimens were characteri zed by elongate, slender body 2.92-6.35 mn long and 0.15-0.49 mm wide. Diameters of both oral and ventral suckers were of about 0.2 mm, thei r ratio 1 : 0.83-1.22 (1.01). Testes and ovary were tandem, ovary ofte n slightly larger. Small eggs measured 0.037-0.048 mm in length and 0. 022-0.030 mm in width. The discussion analyses the systematic position of B. strigosum relative to the ''oldest'' taxa in the genus Brachyle cithum. Cestodes found in another cuckoo in eastern Slovakia, are refe rred to as Brachylecithum sp. This form differs from B. strigosum by s maller size of body and ovary equal or smaller than testes.