Status of Corynosoma (Acanthocephala: Polymorphidae) based on anatomical, ecological, and phylogenetic evidence, with the erection of Pseudocorynosoma n. gen.
Por:
Aznar F.J., De León G.P.-P., Raga J.A.
Publicada:
1 ene 2006
Resumen:
The possession of genital spines has been considered as a key taxonomic trait to differentiate Corynosoma from other genera of the Polymorphidae. However, Corynosoma currently consists of 2 groups of species with clear ecological and morphological divergences: the "marine" group (with ca. 30 species) infects mammals and piscivorous birds in the marine realm, whereas the "freshwater" group (with ca. 7 species) infects waterfowl in continental waters. Species from these groups differ in shape of body and neck, trunk spination, lemnisci length and shape, testes arrangement, and number and shape of cement glands. We tested whether species from these 2 groups formed a monophyletic assemblage based on a phylogenetic analysis by using 15 morphological characters. We also included species of Andracantha, Polymorphus, and Hexaglandula with which potential taxonomic conflicts could most likely arise. We obtained 108 equally most parsimonious trees of 32 steps, with a consistency index (CI) = 0.59, and a retention index (RI) = 0.82. The strict consensus tree indicated that the "freshwater" species of Corynosoma form a monophyletic assemblage closely related to some species of Polymorphus, whereas the "marine" species of Corynosoma are grouped together with Andracantha. Accordingly, Corynosoma is not a monophyletic assemblage, and Pseudocorynosoma n. gen. is proposed for the "freshwater" species of Corynosoma. This decision was strongly supported by (1) a functional comparison of foretrunk muscles between species of Polymophus, Andracantha, and Corynosoma; (2) a multivariate morphometric study of proboscis characters and egg size; and (3) an analysis of ecological patterns of host-parasite relationships. © American Society of Parasitologists 2006.
Filiaciones:
Aznar F.J.:
Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universitat de València, P.O. Box 22085, Valencia 46071, Spain
De León G.P.-P.:
Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universitat de València, P.O. Box 22085, Valencia 46071, Spain
Laboratorio de Helmintología, Instituto de Biología, UNAM, C.P. 04510 México D.F., Mexico
Raga J.A.:
Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universitat de València, P.O. Box 22085, Valencia 46071, Spain
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