Ditrachybothridium piliformis is a new species from the spiral intestine of a cat shark, Galeus sp., from the southern Pacific Ocean. This is only the second species assigned to Ditrachybothridium. It differs from the type species D. macrocephalum in lacking spines on the scolex, a character originally used to diagnose the genus. The diagnoses of the Ditrachybothridiidae and of Ditrachybothridium have been revised to reflect this difference. This new species is further differentiated from the type species in its possession of pectinate spinitriches on the tegument of the scolex. The holdfast structures of this species are weakly muscularized, with no membrane-bound layer of radial muscles, indicating that the holdfast structures are bothria rather than bothridia as described in the most recent literature. Several reports for other species have indicated the same situation in other diphyllideans. The diagnosis of the order has been revised to reflect this finding.

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Proctophantastes brayi n. sp. (Digenea: Zoogonidae; Lepidophyllinae) has been found in the intestine of two species of deep-sea fish Polymixia (silver eye fish) near the island of Erromango in Vanuatu at a depth ranging from 720 to 830 in. Specimen whole mounts, histological and scanning electron microscopy preparations showed that P. brayi differs from the five known species of the genus Proctophantastes (P. abyssorum, R gillissi, R glandulosum, P. infundibulum and P nettastomatis) by the following morphological characters: (i) a slit in the anterior part of the oral sucker, (ii) Laurer's canal is absent, (iii) a more extended periatrial gland than the ones in the other species of Proctophantastes, consisting of divided masses of cells and that form a conspicuous multilobated structure which does not have a membrane-bounded sac, (iv) the distal part of the metraterm has vesicle-like processes which we refer to as metratermal sacs, in addition to atrial sacs, (v) a long extension of the glandular cells surrounding the saccular bladder which extends posteriorly to the excretory pore. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

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The present paper deals with Proctophantastes nettastomatis (Digenea: Zoogonidae; Lepidophyllinae) found in the intestine of three species of deep-sea fish, Dicrolene longimana (Ophidiidae, Ophidiiformes), Bathyuroconger sp. (Congridae, Anguilliformes), and Venefica tentaculata (Nettastomatidae, Anguilliformes). The fish were collected near the islands of Espiritu Santo, Erromango, and Epi, respectively, in the archipelago of Vanuatu (Southern Pacific Ocean) at depths ranging from 561 to 990 m. Morphological and histological analyses showed that the Vanuatu specimens differ from Proctophantastes abyssorum, Proctophantastes gillissi, Proctophantastes glandulosum, Proctophantastes infundibulum, and Proctophantastes brayi but are close to P. nettastomatis discovered in Suruga Bay, Japan. P.nettastomatis is redescribed based both on the observations of our specimens and of the Japanese holotype and paratype. The morphological variability of the species is described. Morphometric data allowed the identification of positive allometric growth for the hindbody, negative allometric growth for the ventral sucker, and a growth phenotypic plasticity between Ophidiiformes and Anguilliformes definitive hosts.

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