Three New Species of Acanthobothrium (Cestoda: Tetraphyllidea) from the Ocellated Electric Ray, Diplobatis ommata, in the Gulf of California, Mexico

摘要

Examination of the spiral intestines of 12 female specimens of the ocellated electric ray Diplobatis ommata from 4 sites in the Gulf of California, Mexico, in 1996 resulted in the discovery of 3 new species of Acanthobothrium: A, dollyae sp. n., A. maryanskii sp. n., and A. royi sp. n..Acanthobothrium dollyae and A. royi are <15 mm in total length, possess <50 proglottids, <80 testes, and a symmetrical ovary, and thus are Category 1 species. Acanthobothrium maryanskii is a Category 5 species; it is >15 mm in total length, possesses >50 proglottids and <80 testes, and has a symmetrical ovary Acanthobothrium royi differs from A. dollyae in the arrangement of its testes and in its possession of a shorter scolex. Acanthobothrium dollyae and A. royi differ from the 4 other Category 1 species known from the eastern Pacific Ocean in total length, proglottid number, cirrus sac size, testis number, extent of vas deferens, and hook shape. Both new species differ from the 6 other Category 1 species known from the western Atlantic Ocean in proglottid number, cirrus sac size, ovary size, genital pore position, and hook shape. Acanthobothrium maryanskii differs from all 6 of the Category 5 species known from the eastern Pacific Ocean and all 5 of the Category .5 species known from the western Atlantic Ocean in hook shape and in its possession of mature proglottids that are wider than long rather than longer than wide. This brings the number of species of Acanthobothrium reported from rays in the order Torpediformes to 12 It brings the number of species of Acanthobothrium reported from the eastern Pacific Ocean to 37 and the total number of Acanthobothrium species reported from elasmobranchs in the Gulf of California to 7. This is the first report of tapeworms from a member of the ray genus Diplobatis.