Cestoda: Proteocephalidae) from Micrurus Diastema A/Finis in Oaxaca, Mexico

Proc. Helminthol. Soc. Wash. 49(1), 1982, pp. 62-64

Proteocephalus micruricola sp. n. (Cestoda: Proteocephalidae) from Micrurus diastema a/finis in Oaxaca, Mexico

WESLEY L. SHOOP AND KENNETH C. CORKUM Department of Zoology and Physiology, L.S.U., Baton Rouge, Louisiana 70803

ABSTRACT: Proteocephalus micruricola sp. n. is described from Micrurus diastema affinis (Jan) in Mexico. P. micruricola is characterized by possessing 121 to 169 testes in two lateral fields, an apical structure on the scolex, and equatorial genital pores. It differs from P. jarara (Fuhrmann, 1927) Brooks, 1978, from Bothrops alternatus in Brazil, in that it has a scolex diameter of 720 to 760 yum, neck length of 11.75 mm, vaginal pores opening posterior to the cirrus pouch in the majority (85%) of proglottids, and onchosphere diameter of 15 to 18 ^u,m.

During an expedition into southern Mexico to examine snakes for mesocer- cariae of the trematode genus Alaria one of us (WLS) had the opportunity to examine a coral snake, Micrurus diastema affinis (Jan), for helminths. We found two gravid strobilae of an undescribed proteocephalid tapeworm in the small intestine. It is unusual to find proteocephalids in fossorial snakes as these worms usually infect aquatic vertebrates such as fish, amphibians, and semi-aquatic snakes. To our knowledge, no other parasites have been reported from this host. The worms were fixed in the field and stored in AFA. They were subsequently stained in Semichon's aceto-carmine, dehydrated in a series of alcohols, and mounted in Permount. Measurements are in micrometers unless otherwise stated; means are followed by the ranges in parentheses. After measurements were taken, one specimen was dismounted and prepared for scanning electron microscopy for additional observations on scolex morphology. Line drawings were prepared with the aid of a microprojector. Proteocephalus micruricola sp. n. (Figs. 1^1) DESCRIPTION (based on two specimens): Proteocephalidea Mola, 1928; Proteo- cephalidae La Rue, 1911; Proteocephalus Mola, 1929. Length of strobila 275 (259-290) mm. Scolex globose, 475 (450-500) long by 740 (720-760) wide, with four muscular suckers; suckers 255 (250-260) long by 305 (300-310) wide. Apical structure consisting of a slight elevation with an inconspicuous, funnel-shaped depression. Neck 11.75 (11.5-12.0) mm long by 720 (510-930) wide. Scolex and neck spinous. Strobila acraspedote. Immature proglottids 795 (540-1,200) long by 1,780 (1,500-2,200) wide (N = 20); mature proglottids 1,450 (1,150-1,800) long by 2,090 (1,850-2,400) wide (N = 20); and gravid proglottids 3,200 (2,100-4,100) long by 1,750 (1,400-2,200) wide (N = 10), with a width to length ratio of 1:1.9 (1.1-2.9). Calcareous corpuscles numerous in the cortical parenchyma. Excretory system composed of paired dorsolateral and ventrolateral longitudinal canals; ventrolateral canals displaced laterally and four times the diameter as the dorsolateral canals; no transverse commissures present. MALE GENITALIA: Testes in two distinct lateral fields, 140 (121-169) total, 43 (29-56) preporally, 24 (17-29) postporally, 73 (60-90) antiporally; 75 (55-100) in diameter (N = 25). Vas deferens describes a broad series of coils between the

Figures 1-4. Proteocephalus micruricola sp. n. 1. Scolex. 2. Immature proglottid. 3. Mature proglottid. 4. Gravid proglottid. cirrus pouch and uterus. Cirrus pouch transverse, 333 (300-350) long by 97 (80-105) wide (N = 25); ratio of cirrus pouch length to proglottid width 1:6.4 (5.1-6.9). Genital pores alternate irregularly in the anterior 51 (48-56) % of proglottids. Genital pore slightly elevated. FEMALE GENITALIA: Ovary bilobate, 1,052 (820-1,250) wide (A/ = 20), lobes joined by a narrow isthmus; ovary confined to the area between the dorsolateral excretory canals. MehhY gland complex conspicuous. Vagina opens posterior to the cirrus pouch in 85% of proglottids; distal part of the vagina thick walled,

Copyright © 2011, The Helminthological Society of Washington 64 • PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY without a sphincter. Uterus preformed as a simple tube in mature proglottids; when gravid the uterus expands laterally into 40 (35-53) horizontal, layered di- verticula on each side (N = 10). Vitellaria in two narrow bands just lateral to the ventrolateral excretory canal, and extends almost the entire length of the proglottid. Eggs 22 (20-23) in diameter (N = 10) with onchospheres 17 (15-18) in diameter (N = 10). TYPE HOST: Micmms diastema affinis (Jan). SITE: Small intestine. TYPE LOCALITY: Valle Nacional, Oaxaca, Mexico. HOLOTYPE: USNM Helm. Coll. 76375. Discussion Freze (1965) placed those proteocephalids with simple scolices from amphibians in Batrachotaenia, those from snakes in Ophiotaenia, and those from turtles in Testudotaenia. In addition, he placed similar proteocephalids from fish in a different genus, Proteocephalus, based on host specificity and absence of a preformed uterus in mature proglottids. Brooks (1978) evaluated the characters used by Freze and concluded that they were not significant in view of similar scolex morphology, arrangement of gonads, and available life history information. Con- sequently, Brooks considered the three genera, sensu Freze, as junior synonyms of Proteocephalus. We concur with Brooks until additional information becomes available. Proteocephalus micruricola is most similar to P. jarara (Fuhrmann, 1927) Brooks, 1978, from Bothrops alternatus in Brazil, in possessing testes in two distinct fields, number of testes, presence of an apical structure, and equatorial genital pores. P. micruricola differs from P. jarara in the following characters: (1) P. micruricola has a scolex diameter of 720 to 760 whereas that of P. jarara measures 1,100 to 1,200; (2) the neck length of P. micruricola averages 11.75 mm while that of P. jarara is under 5 mm; (3) the vaginal pores of P. micruricola open posterior to the cirrus pouch in 85% of proglottids whereas P. jarara never open posterior to the cirrus pouch; and (4) the onchospheres of P. micruricola are 15 to 18 in diameter whereas those of P. jarara measure 10 in diameter. Acknowledgments The authors express their appreciation to Randy H. Vaeth, Museum of Zool- ogy, L.S.U., who kindly identified the coral snake used in this report. Literature Cited Brooks, D. R. 1978. Systematic status of proteocephalid cestodes from reptiles and amphibians in North America with descriptions of three new species. Proc. Helminthol. Soc. Wash. 45:1-28. Freze, V. I. 1965. Essentials of Cestodology. Vol. V. Proteocephalata in Fish, Amphibians, and Reptiles. Akad. Nauk, Moscow. (Israel Program for Scientific Translations, Jerusalem, 1969.) 597 pp.