Influence of size of sporocyst inoculum upon the size and number of sarcocysts of Sarcocystis falcatula which develop in the brown-headed cowbird

The influence of the number of sporocysts in the inoculum of Sarcocystis fa lcatula on the morphology of the sarcocysts has not been reported in the li terature. To determine if there is a relationship, different number of spor ocysts were inoculated orally into wild-caught cowbirds. After 14 weeks, th e cowbirds were euthanised and muscle tissue was examined grossly and by hi stologic sections. Sarcocysts were compared based on the numbers which deve loped and their sizes. There was a linear increase in the number of sarcocy sts as the size of the inoculum increased, however, the size of the sarcocy sts became smaller with the increase in number of sporocysts inoculated. (C ) 2001 Elsevier Science B.V. All rights reserved.