Six Species of Acanthobothrium (Eucestoda: Tetraphyllidea) in Stingrays (Chondrichthyes: Rajiformes: Myliobatoidei) from Ecuador

Authors

Fernando Marques, University of Toronto
Daniel R. Brooks, University of TorontoFollow
Ramiro Barriga, Escuela Politecnica Nacional (Quito, Ecuador)

Date of this Version

6-1997

Comments

Published in the Journal of Parasitology (June 1997) 83(3): 475-484. Copyright 1997, the American Society of Parasitologists. Used by permission.

Abstract

Six species of Acanthobothrium, 4 described as new, are reported in stingrays from southern Ecuador. Acanthobothrium atahualpai n. sp. in Gymnura afuerae most closely resembles Acanthobothrium fogeli and Acanthobothrium parviuncinatum,/i> by having bothridial hooks with recurved prongs and short handles. It differs from A. fogeli by having bothridial hooks 163-195 μm vs. 78-114 μm long and averaging 25 vs. 32 testes per proglottis; it differs from A. parviuncinatum by having bothridial hooks 163-195 μm vs. 87 μm long and averaging 25 vs. 13 testes per proglottis. Acanthobothrium minusculus n. sp. in Urolophus tumbesensis most resembles Acanthobothrium campbelli and Acanthobothrium vargasi by being no more than 3 mm long and having 6-30 testes per proglottis. It can be distinguished from them by having bothridial hooks averaging 86 μm vs. 108-111 μm and 130-133 μm long, and 6-10 vs. 15-23 and 22-29 testes per proglottis, respectively. Acanthobothrium monksi n. sp. in Aetobatus narinari resembles Acanthobothrium tasajerasi from Himantura schmardae by having a prominent genital atrium and a large globose cirrus sac; it differs by averaging 21 vs. 35 testes per proglottis and having bothridial hooks averaging 150 μm vs. 165 μm long. Acanthobothrium obuncus n. sp. in Dasyatis longus resembles a group of species characterized by wider than long to square immature and mature proglottides, bothridia at least partially fused to the scolex at their posterior ends, and asymmetrical ovarian arms with aporal arms extending anteriorly to the vaginal level. It resembles Acanthobothrium americanum by averaging 73 vs. 72 testes per proglottis, but differs by having bothridial hooks averaging 120-131 μm vs. 151 μm long; it resembles Acanthobothrium chilensis by having bothridial hooks averaging 120-131 μm vs. 130 μm long, but differs by averaging 73 vs. 90 testes per proglottis. Acanthobothrium campbelli in Urotrygon chilensis and Acanthobothrium costarricense in Dasyatis longus, previously known in those hosts from the Pacific coast of Costa Rica, are reported from Ecuador for the first time.