DESCRIPTION OF HETEROPLECTANUM-OLIVERI SP-N (MONOGENEA, DIPLECTANIDAE) AND COMMENTS ON THE HELMINTH FAUNA OF KYPHOSUS-ELEGANS (PERCIFORMES,KYPHOSIDAE) FROM CHAMELA BAY, MEXICO

Heteroplectanum oliveri sp. n. (Monogenea: Monopisthocotylea: Diplecta nidae) is described from Kyphosus elegans Peters, 1869 (Perciformes: K yphosidae) in Chamela Bay, Jalisco, Mexico. It differs from other spec ies of the genus in the structure of the cirrus complex, in having a s pined cirrus and a strongly sclerotized genital atrium. Eight addition al helminth species are reported in K. elegans: Heteroplectanum nenue (Yamaguti, 1968) Rakotofiringa, Oliver and Lambert, 1987, H. kyphosi ( Yamaguti, 1968) Oliver, 1987, Neobivagina aniversaria Bravo-Hollis, 19 79, Deontacylix ovalis Linton, 1910, Opisthadena dimidia Linton, 1910, Jeancadenatia dohenyi Winter, 1956, Filisoma bucerium Van Cleave, 194 0, and Ascarophis girellae Yamaguti, 1935, and Anguillicolidae Yamagut i, 1935 (larvae). Chamela Bay is a new locality for all helminth speci es, except for N. aniversaria. Kyphosus elegans is a new host for D. o valis, Ascarophis girellae, and Anguilicollidae larvae. Taxonomic prob lems associated with these helminths are discussed, and the importance of the Kyphosus host-parasite system as a coevolving unit is stressed .