Two new species of Bothriocephalus Rudolphi, 1808 (Cestoda: Bothriocephalidea) from marine fish off Australia and New Caledonia

Two new species of bothriocephalidean tapeworms, Bothriocephalus australis n. sp. from the flatheads Platycephalus bassensis Cuvier (type host) and P. aurimaculatus Knapp off southern Australia and B. celineae n. sp. from a hybrid serranid Cephalopholis aurantia (Val.) x C. spiloparaea (Val.) from off New Caledonia, are described. B. australis is unique in the possession of the combination of the three characters: an elongate, obliquely situated cirrus-sac; a wide genital atrium surrounded by chromophilic cells; and a well-developed apical disc. B. celineae is typified by the presence of a low number of testes per segment (14-26), forming one or two incomplete longitudinal bands on each side of segment, and the small size of the strobila (total length 24 mm) which consists of less than 100 segments.

A taxonomic Study of Species of Bothriocephalus Rudolphi, 1808 (Cestoda: Pseudophyllidea) from Eels in Japan: Morphological and Molecular Evidence for the Occurrence of B. claviceps (Goeze, 1782) and Confirmation of the Validity of B. Japonicus Yamaguti, 1934

A taxonomic study of specimens of Bothriocephalus from eels ( Anguilla spp.) in Japan has demonstrated the occurrence of two species, B. claviceps (Goeze, 1782) and B. japonicus Yamaguti, 1934. The former species is a parasite of eels ( A. anguilla and A. rostrata ) in the Holarctic Region and was recently reported from A. marmorata in Japan. The conspecificity of tapeworms newly found in an eel ( A. ? japonica ) from Lake Biwa, central Japan, with B. claviceps has been confirmed by the great similarity of their ITS-2 gene sequences (similarity 95.3% and 95.2%). However, the sequences of worms identified as B. claviceps from A. marmorata differed considerably from those of B. claviceps from two populations of A. anguilla from Europe and the above-mentioned one from Japan (similarity 66.3%, 67.1% and 65.1 %, respectively), thus indicating that the former cestodes may have been misidentified. This assumption was confirmed by morphological evaluation of a voucher specimen from A. marmorata. The morphology of this cestode, as well as those from A. japonica from two localities in Japan (Lakes Biwa and Suwa), indicates their conspecificity with B. japonicus. The validity of this taxon has been confirmed on the basis of a re-examination of the type-specimens. The two taxa, B. japonicus and B. claviceps, differ from each other in the shape and length of the scolex (619-730 microm in B. japonicus versus 1,180-2,100 microm in B. claviceps ), the relative position of the cirro-vaginal and uterine pores (opposite each other in relation to the median line of the body in B. japonicus versus tandem or slightly offset along the median line in the latter species), and the size of the eggs (41-52 x 28-35 microm in B. japonicus versus 50-70 x 31-43 microm in B. claviceps ).

Bothriocephalus gadellus n. sp. (Cestoda: Bothriocephalidae) from the beardless codling Gadella imberbis (Vaillant) (Moridae) in the southwestern Gulf of Mexico, with a review of species of Bothriocephalus Rudolphi, 1808 reported from gadiform fishes

Bothriocephalus gadellus n. sp. is described from the intestine of the beardless codling Gadella imberbis (Gadiformes: Moridae) from the southwestern Gulf of Mexico. It resembles B. scorpii, the type-species of Bothriocephalus, and B. manubriformis, the only species of the genus reported from the Gulf of Mexico. B. gadellus n. sp. differs from both species in having four excretory canals on each side of the proglottid (three per side in B. scorpii; two per side anastomosing to form an extensive plexus throughout the medulla in B. manubriformis ), 24-33 testes per proglottid (30-60 in B. scorpii; 60-100 in B. manubriformis), a total length of 31-47 mm (32-950 mm in B. scorpii; 130-1,000 mm in B. manubriformis), and a seminal receptacle and wing-like expansions on each proglottid (absent in B. scorpii and B. manubriformis), as well as lacking two sets of reproductive organs per proglottid (present in B. scorpii) and a vagina with a bulbous sphincter near the opening (present in B. manubriformis). An amendment to the generic diagnosis of Bothriocephalus might be warranted if other species of this genus are found to possess a seminal receptacle. B. gadellus n. sp. appears to be like those species of Bothriocephalus that can utilise two intermediate hosts (copepod and fish). B. ellipticus and B. neglectus are designated as species inquirendae. This is the first report of a cestode from a morid fish in the Gulf of Mexico, and the first report of a parasite from a species of Gadellus.

Biology of gyrocotylideans with emphasis on reproduction, population ecology and phylogeny

The Gyrocotylidea is a group of platyhelminths comprising only a dozen or so species which have been placed in three genera, Oyrocotyle Diesing, 1850, Amphiptyches Grube and Wagener in Wagener, 1852 and Gyrocotyloides Fuhrmann, 1930. All species are highly specific to chimaeroid fish, a small group of present-day holocephalans, and are restricted to the spiral valve intestine of these hosts.