Capillaria colubra sp. n. from the Oviducts of Coluber constrictor priapus

Abstract

Capillaria colubra sp. n. is described from the oviducts of the southern black racer, Coluber constrictor priapus, from southern Louisiana. It is distinguished from the closely related Capillaria heterodontis by its larger size, transverse striations on the spicule and spicule sheath, and a more elaborate caudal bursalike expansion and two ventral papillae in the male. It is smaller and has a lower ratio of anterior to posterior body regions than Capillaria longispicula. It differs from other snake capillarids in its greater size, higher ratio of anterior to posterior body regions, larger eggs, and more elaborate male caudal bursalike expansion. This is the first capillarid reported from the oviducts of a vertebrate host. Several species of Capillaria have been reported from snakes in South and Middle America (Teixiera de Freitas and Lent, 1935; Aravjo and Gandra, 1943; Caballero and Cerecero, 1944; Yamaguti, 1961). However, Capillaria heterodontis Harwood, 1932, is apparently the only species described from a snake endemic to the United States. Between 1967 and 1969 17 specimens of Capillaria were removed from the oviducts of three southern black racers collected near New Orleans, Louisiana. These specimens represent a new species. Capillarids were removed from the oviducts, fixed in glacial acetic acid, stored in a mixture of alcohol, formalin, and glycerin, and studied in glycerin mounts after evaporation of the alcohol at room temperature. Drawings were made with the aid of a camera lucida. In the following description measurements are in millimeters unless otherwise noted. Capillaria colubra sp. n. (Figs. 1-6) Definition: Trichuridae Railliet, 1915; Capillariinae Railliet, 1915; Capillaria Zeder, 1800. Body diameter increasing from anterior to about the posterior three-fourths. Body very slender, threadlike. Cuticle smooth. Two lateral bacillary bands. Mouth small, porelike. Esophagus consisting of a single chain of stichocytes, some cells darker than others and containing granules, alternating with lighter cells devoid of granules. Anterior region shorter than posterior region of body in male and female. Female slightly longer than male. Received for publication 10 October 1969. * Supported in part by a Predoctoral Fellowship, 5-F01-GM-38,070, awarded by National Institute of General Medical Sciences, NIH, Public Health Service. Male (9 specimens): 19.56 to 26.40 (21.83) long, 68 to 78 /L (72) maximum width. Anterior region of body 5.54 to 6.90 (5.96) long, with muscular pharynx 304 to 552 /L (425) long, followed by 40 to 59 (45) stichocytes. Posterior egion of body 13.84 to 19.50 (15.88) long. Ratio of anterior to posterior region 1:2.4 to 1:2.9 (1:2.7). Ratio of anterior region to total length 1:3.4 to 1:3.9 (1:3.7). Posterior extremity bears ventrally a small bursalike expansion and 2 small papillae. Body terminates in short blunt tail dorsally. Cloaca 3.31 to 3.70 (3.45) in length. Anus subterminal, surrounded by bursa. Spicule 2.22 to 2.96 (2.59) long, 12 to 17 /u (14) at maximum width, transversely striated, with blunt tip. Spicule sheath long, transversely striated, 18 to 26 / (22) at maximum width. Female (8 specimens): 29.15 to 36.46 (31.99) long, 77 to 100 ,u (87) at maximum width. Anterior region of body with muscular pharynx 276 to 684 /, (490) long, followed by 40 to 52 (48) stichocytes. Posterior region 24.51 to 30.29 (25.71) long. Ratio of anterior to posterior regions 1:3.4 to 1:4.9 (1:4.1). Ratio of anterior to total length 1:4.4 to 1:5.9 (1:5.1). Vulva 100 to 150 A (130) posterior to last stichocyte, anterior and posterior lips slightly salient. Anus subterminal. Posterior extremity slightly rounded and blunt, caudal papillae absent. Eggs unembryonated, 61 to 70 / (65) in length, 28 to 31 ,/ (30) in width. Holotype male: USNM Helm. Coll. No. 70563. Allotype female: USNM Helm. Coll. No. 70564. Paratypes: USNM Helm. Coll. No. 70565. Host: Coluber constrictor priapus Dunn and Wood, 1939. Location: Posterior region of oviducts; anterior end threaded into the mucosa, posterior region free in the lumen. Locality: Covington, Louisiana, USA 30?30' N, 90010' W. DISCUSSION The capillarids of cold-blooded vertebrates were thoroughly reviewed by Teixiera de Freitas and Lent (1935). In addition, Yama-