Abstract
Two new species, Dendromonocotyle citrosa n. sp. off Dasyatis chrysonota (Smith) from Two Oceans Aquarium in Cape Town and off Himantura gerrardi (Gray) from uShaka Sea World in Durban and D. ukuthena n. sp. off H. gerrardi and H. uarnak (Forsskal) also from uShaka Sea World in Durban, are described. These can be distinguished from previously described Dendromonocotyle species by the morphology of the distal portion of the male copulatory organ and the proximal part of the vagina. Vaginal morphology is proposed as an important diagnostic character for species in the genus. Dendromonocotyle colorni Chisholm, Whittington & Kearn, 2001 which was originally recorded from H. uarnak in Israel, was discovered on H. uarnak sympatrically with D. ukuthena n. sp. and with D. citrosa n. sp. and D. ukuthena n. sp. off H. gerrardi. Minor differences in the number of papillary sclerites, the presence of septal tripartite sclerites and in the number of eyespots were seen between D. colorni collected from H. uarnak and H. gerrardi from uShaka Sea World and those originally described off H. uarnak from Israel. We demonstrate that the position of the marginal hooklets can be used to determine the orientation of the haptor of all representative Dendromonocotyle species with or without hamuli. We conclude that Dendromonocotyle species may not be as host-specific as previously believed and that minor differences in morphology are host or geographically induced.References
Bravo-Hollis, M. (1969) Helmintos de peces del Pacifico Mexicano. XXX. Descripción de tres monogéneos de la familia Monocotylidae Taschenberg, 1879. Anales del Instituto de Biología, Universidad Nacional Autónoma de México. Serie Zoología, 2, 161–178.
Bullard, S.A., Frasca, S. Jr. & Benz, G.W. (2001) Gill lesions associated with Erpocotyle tiburonis (Monogenea: Hexabothriidae) on wild and aquarium-held bonnethead sharks (Sphyrna tiburo). Journal of Parasitology, 87, 972–977.
Cheung, P. & Whitaker, B. (1993) A new dendromonocotylinid (monogenean) from the skin of the roughtail stingray, Dasyatis centroura Mitchill. Journal of Aquariculture and Aquatic Sciences, 6, 63–68.
Chisholm, L.A., Glennon, V. & Whittington, I.D. (2005) Dendromonocotyle bradsmithi n. sp. (Monogenea: Monocotylidae) from the skin of Myliobatis australis (Elasmobranchii: Myliobatidae) off Adelaide and Perth, Australia: description of adult and larva. Zootaxa, 951, 1–15.
Chisholm, L.A., Morgan, J.A.T., Adlard, R.B. & Whittington, I.D. (2001b) Phylogenetic analysis of the Monocotylidae (Monogenea) inferred from 28S rDNA sequences. International Journal for Parasitology, 31, 1537–1547.
Chisholm, L.A., Wheeler, T.A. & Beverley-Burton, M. (1995) A phylogenetic analysis and revised classification of the Monocotylidae Taschenberg, 1879 (Monogenea). Systematic Parasitology, 32, 159–191.
Chisholm, L.A. & Whittington, I.D. (1995) A revision of Dendromonocotyle Hargis, 1955 (Monogenea: Monocotylidae) with a description of a new species from Pastinachus sephen (Forsskål) (Myliobatiformes: Dasyatidae) from the Great Barrier Reef, Australia. Journal of National History, 29, 1093–1120.
Chisholm, L.A. & Whittington, I.D. (2005) Dendromonocotyle lasti n. sp. from the skin and Monocotyle caseyae n. sp. (Monogenea: Monocotylidae) from the gills of Himantura sp. (Dasyatidae) in Moreton Bay, Queensland, Australia. Systematic Parasitology, 60, 81–89.
Chisholm, L.A., Whittington, I.D. & Fischer, A.B.P. (2004) A review of Dendromonocotyle (Monogenea: Monocotylidae) from the skin of stingrays and their control in public aquaria. Folia Parasitologica, 51, 123–130.
Chisholm, L.A., Whittington, I.D. & Kearn, G.C. (2001a) Dendromonocotyle colorni sp. n. (Monogenea: Monocotylidae) from the skin of Himantura uarnak (Dasyatidae) from Israel and a new host record for D. octodiscus Hargis, 1955 from the Bahamas. Folia Parasitologica, 48, 15–20.
Euzet, L. & Maillard, C. (1967) Parasites de poisons de mer ouest-africains, récoltê par J. Cadenat. VI. Monogènes de sélaciens. Bulletin de l’Institut Fondamental d’Afrique Noire, Série A, Sciences Naturelles, 29, 1435–1493.
Hargis, W.J., Jr. (1955) Monogenetic trematodes of Gulf of Mexico fishes. Part V. The subfamily Capsaloidea. Transactions of the American Microscopical Society, 74, 203–225.
Harris, P.D., Cable, J., Tinsley, R.C. & Lazarus, C.M. (1999) Combined ribosomal DNA and morphological analysis of individual gyrodactylid monogeneans. Journal of Parasitology, 85, 188–191.
Ho, J.S. & Perkins, P.S. (1980) Monogenea from fishes of the Sea of Japan. Part 1. Order Monopisthocotylea. Annual Report of the Sado Marine Biological Station Niigata University, 10, 1–10.
Huyse, T., Poulin, R. & Théron, A. (2005) Speciation in parasites: a population genetics approach. Trends in Parasitology, 21, 469–475.
Olson, A.C. & Jeffries, M. (1983) Dendromonocotyle californica sp. n. (Monogenea: Monocotylidae) from the bat ray, Myliobatis californica, with a key to species. Journal of Parasitology, 69, 602–605.
Sasal, P., Trouvé, S., Müller-Graf, C. & Morand, S. (1999) Specificity and host predictability: a comparative analysis among monogenean parasites of fish. Journal of Animal Ecology, 68, 437–444.
Taschenberg, E.O. (1879) Ziir systematik der monogenetischen Trematoden. Zeitschrifi fiir die Gesammten Naturwissenschaften (Berlin), 52, 232–265.
Whittington, I.D., Chisholm, L.A. & Rohde, K., 2000. The larvae of Monogenea (Platyhelminthes). Advances in Parasitology, 44: 139–232.
Young, P.C. (1967) A taxonomic revision of the subfamilies Monocotylinae Gamble, 1896 and Dendromonocotylinae Hargis, 1955 (Monogenoidea: Monocotylidae). Journal of Zoology, London, 153, 381–422.