GAMMA-IONIZATION OF PHAGICOLA-LONGA (TREMATODA, HETEROPHYIDAE) IN MUGILIDAE (PISCES) IN SAO-PAULO, BRAZIL

The mullet (Mugilidae) is a fish caught in large quantities in brackis h and marine waters of the southern Brazilian coast, which in conseque nce of its raw consumption as ''sashimi'', a typical Japanese dish, ha s led to ten cases of human infection by Phagicola longa in Sao Paulo, Brazil. The mullet acts as a second intermediate host for the parasit e, as in human heterophyiasis in the Near and Far East. In order to co ntrol these infections under commercial storage, conditions and in raw consumption, the radiolysis of P. longa was studied in three mullet s pecies - the silver mullet (Mugil curema), the grey mullet (M. platanu s) and the ''parati-pema'' (Mugil sp.) - subjected to ionization rangi ng from 1.0 to 10.0 kGy (2.21 kGy/h). It was observed that 1.0 and 2.0 kGy caused a motility decrease in silver mullet parasites from 100% t o 15% and 17%, and that doses of 4.0 and 10.0 kGy caused metacercaria inviability. The parasite motility decreased in the grey mullet treate d with doses of 2.0, 2.5, 3.0 and 3.5 kGy, from 56% to 31%, 9%,18% and 5%, respectively, 4.0 kGy tending to be the control dose for P. longa . This dose also controls other metacercaria found in the ''parati-pem a'', without changing the odor, color or appearance of the treated mul let.