Three diplectanid monogeneans from marine finfish (Epinephelus spp.) in the Far East

Abstract

Two new species of diplectanid monogeneans, Diplectanum grouperi and Pseudorhabdosynochus coioidesis from the marine finfish Epinephelus coioides and E. aerolatus(Serranidae), cultured in floating cages in Malaysia, Indonesia and Hong Kong, were described and compared with P. lantauensis Beverley-Burton and Suriano, 1981 from the same hosts. There is no other close species sharing the features of Diplectanum grouperi. The possession of a copulatory organ with an open cup-like proximal part and a narrow tubular distal part is a main distinguished feature of D. grouperi. Pseudorhabdosynochus coioides is most closely related to P. epinepheli Yamaguti, 1938, but can be distinguished from it by the shape and the size of the haptor, hamuli, copulatory organ, the lack of a muscular bulbus ejaculatorius, a greater number of rows in the squamodiscs and the location of the testis. Pseudorhabdosynochus lantauensis from the present hosts differs from that described from the original hosts, Epinephelus brunneus and E. fario in the shape of the dorsal bar and vagina.