Justine, J.-L.; Euzet, L. (2006). Diplectanids (Monogenea) parasitic on the gills of the coralgroupers Plectropomus laevis and P. leopardus (Perciformes, Serranidae) off New Caledonia, with the description of five new species and the erection of Echinoplectanum n. g. Systematic Parasitology. 64(3): 147-172.
Diplectanids (Monogenea) parasitic on the gills of the coralgroupers Plectropomus laevis and P. leopardus (Perciformes, Serranidae) off New Caledonia, with the description of five new species and the erection of Echinoplectanum n. g
Systematic Parasitology
64(3): 147-172
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Echinoplectanum n. g. is erected for diplectanids which have a male copulatory organ comprising a tubular sclerotised penis with a muscular reservoir at its proximal extremity and an protrusible cirrus, often with spiny ridges, at its distal extremity, and a female copulatory organ comprising a sclerotised vaginal sac, often with two thin tubes. All species have similar squamodiscs made of rows of rodlets, with the central rows forming closed circles, and haptoral parts with a similar shape but different measurements; they are distinguished on the basis of the size and morphology of the male copulatory organ and sclerotised vagina. Five new species are included in Echinoplectanum and are all parasites of coralgroupers, Plectropomus spp., off New Caledonia, South Pacific. Two are from P. laevis (Lacépède): E. laeve n. sp. (type-species) has a large elongate penis, 53µm in length, a cirrus with spiny ridges and a spherical vagina with two long thin tubes; and E. chauvetorum n. sp. has a large elongate penis, 51µm in length, a cirrus with thin spiny ridges, and a pear-shaped vagina with two short thin tubes. Three species are from P. leopardus (Lacépède): E.?leopardi n. sp. has an elongate penis, 36µm in length, an unspiny cirrus and a triangular vagina; E.?pudicum n. sp. has a very small elongate penis 14µm in length and no visible vagina; and E. rarum n. sp. has a short thick penis 18µm in length and a ring-shaped vagina with two thin tubes. In addition, Diplectanum plectropomi Young, 1969, from P. maculatus off Western Australia, and D. echinophallus Euzet & Oliver, 1965 from Epinephelus marginatus in the Mediterranean Sea and Senegal, West Africa, both herein redescribed from the type-specimens, are transferred to Echinoplectanum, as E. plectropomi n. comb. and E.?echinophallus n. comb., respectively. Six of the seven species of Echinoplectanum are parasitic in members of Plectropomus from the South West Pacific, but one (E. echinophallus) is a parasite of Epinephelus marginatus and has been recorded only from the Mediterranean and East Atlantic; it is suggested that Echinoplectanum is associated with Plectropomus, a basal genus among the epinephelines, and that host-switching to Epinephelus marginatus occurred, whose distribution extends from Europe to the Indian Ocean. Morphological characteristics of the copulatory organs suggest that a “chastity belt versus spiny penis” sperm competition pattern prevails in Echinoplectanum spp.
