COCCIDIAN PARASITES (APICOMPLEXA) FROM SNAKES IN THE SOUTH-CENTRAL AND SOUTHWESTERN UNITED-STATES - NEW HOST AND GEOGRAPHIC RECORDS

Four hundred thirty-five leptotyphlopid, colubrid, elapid, and viperid snakes were collected from various localities in Arkansas, New Mexico , Oklahoma, and Texas, and their feces were examined for coccidian par asites. Of these, 131 (30%) were passing oocysts or sporocysts of at l east 1 coccidian; 88 (67%) of the infected snakes had only 1 species o f coccidian when they were examined. Aquatic and semiaquatic snakes ac counted for 48% of the infections, whereas strictly terrestrial snakes comprised the other 52%. There was more than a 2-fold difference in p revalence among these 2 groups as 63 of 129 (49%) of the aquatic and s emiaquatic snakes versus 68 of 306 (22%) of the terrestrial snakes har bored coccidia. Most terrestrial snakes were infected by species of Ca ryospora and Sarcocystis that are either facultatively or obligatorily heteroxenous. The aquatic and semiaquatic species most often harbored eimerians. Attempts to transmit some of the Sarcocystis spp. experime ntally from Crotalus atrox to Mus musculus, Peromyscus leucopus, Perom yscus maniculatus, or Microtus ochrogaster were unsuccessful. This rep ort documents 27 new host and several distributional records for cocci dians from snakes in the southcentral and southwestern United States.