Description of Two New Species of Coccidia (Apicomplexa: Eimeriorina) from Flat-Headed Snakes, Tantilla gracilis (Serpentes: Colubridae) and Reclassification of Misnomer Species within the Genera Isospora and Sarcocystis from Snakes

Abstract

Two new species of coccidia were recovered from the feces of flat-headed snakes, Tantilla gracilis, from Texas and Arkansas, U.S.A. Oocysts of Caryospora gracilis n. sp. are spherical or subspherical, 23.7 x 22.5 (21-25 x 21-24) #m, with a thick, bilayered wall and a shape index (length/width) of 1.06 (1.00-1.12). A micropyle is absent, but an oocyst residuum and polar granule are present. Sporocysts are ovoidal, 17.1 x 12.7 (1518 x 11-13.5) ,im, with Stieda and substieda bodies. The sporocyst shape index is 1.34 (1.29-1.40). Oocysts of Isospora wilsoni n. sp. are spherical, rarely subspherical, 17.2 x 17.0 (15-19 x 14.5-19) Aim, with a thick, bilayered wall and a shape index of 1.01 (1.001.11). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoidal, 10.9 x 8.4 (10.5-12 x 8-9) ,im, with Stieda and substieda bodies and a shape index of 1.30 (1.24-1.40). In addition to these new coccidia, a check-list of the coccidian genera Isospora and Sarcocystis representing species misidentified from snakes, which places most members within the genus Sarcocystis, is presented. The flat-headed snake, Tantilla gracilis, ranges from southwestern Illinois, Missouri, and eastern Kansas to southern Texas and Coahuila, Mexico (Conant & Collins, 1991). This small, secretive snake prefers rocky hillsides and is found most often in sandy soils associated with limestone. Prey include centipedes, insect larvae, and various invertebrates (Conant & Collins, 1991). Little is known of the biology of snakes in the genus Tantilla and only a few taxonomic and natural history studies have been published (see Wilson, 1982, 1983, 1987). Coccidia never have been reported from any member of the genus, but our studies revealed two undescribed species that we report below as new. MATERIALS AND METHODS Between March and August 1991, 12 flat-headed snakes were captured alive by hand from various localities in Arkansas and Texas, U.S.A. Snakes were ' We thank the Texas Parks and Wildlife Department and Arkansas Game and Fish Commission for scientific collecting permits SPR-0390-027 and 831 to C.T.M. and S.E.T., respectively. We also thank Dr. James R. Dixon for providing specimens of T. gracilis from Llano County, Texas. TRANS. AM. MICROSC. SOC., 111(1): 50-60. 1992. ? Copyright, 1992, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.112 on Wed, 29 Jun 2016 04:50:26 UTC All use subject to http://about.jstor.org/terms VOL. 111, NO. 1, JANUARY 1992