Gill pathology caused by infestations of adult and preadult Dissonus manteri Kabata (Copepoda : Dissonidae) on coral trout, Plectropomus leopardus (Lacepede), (Serranidae)

Adult and preadult Dissonus manteri attached to the gills of Plectropomus leopardus cause significant pathology in the form of large hyperplastic nodules on the afferent (leading), edges of gill filaments. Nodules result from the dual actions of parasite attachment and feeding. The host response is characterized by severe epithelial hyperplasia, supplemented by fibroplasia and inflammation. Parasites attach close to the gill arch near the base of filaments. They have little effect on gill vasculature as the maxillipeds penetrate the filament superficial to the efferent filament artery and do not interfere with the blood vessels of the secondary lamellae. Tissue proliferation is limited to the wide portion of filament 'edge' epithelium in the proximal third and also does not extend to the secondary lamellae. Nodules are most numerous towards the ends of hemibranchs and are generally absent from the central regions. Leading hemibranchs bear significantly more nodules than their trailing counterparts. Of the total number of nodules, 20.5% are located on the pseudobranchs. Distribution patterns are considered to be primarily the result of D. manteri avoiding strong water currents, although this cannot explain the difference between numbers on leading and trailing hemibranchs.

A review of the Apocreadiidae Skrjabin, 1942 (Trematoda : Digenea) and description of Australian species

The Apocreadiidae is reviewed and is considered to include genera recognised previously within the families Apocreadiidae, Homalometridae, Schistorchiidae, Sphincterostomatidae and Trematobrienidae. Key features of the family are extensive vitelline follicles, eye-spot pigment dispersed in forebody, I-shaped excretory vesicle, no cirrus-sac and genital pore opening immediately anterior to the ventral sucker (usually) or immediately posterior to it (Postporus Manter, 1949). Three subfamilies and 18 genera are recognised within the Apocreadiidae. The Apocreadiinae comprises Homalometron Stafford, 1904 (new syn. Barbulostomum Ramsey, 1965), Callohelmis n. g., Choanodera Manter, 1940, Crassicutis Manter, 1936, Dactylotrema Bravo-Hollis & Manter, 1957, Marsupioacetabulum Yamaguti, 1952, Microcreadium Simer, 1929, Myzotus Manter, 1940, Neoapocreadium Siddiqi & Cable, 1960, Neomegasolena Siddiqi & Cable, 1960, Pancreadium Manter, 1954, Procaudotestis Szidat, 1954 and Trematobrien Dollfus, 1950. The Schistorchiinae comprises Schistorchis Luhe, 1906, Sphincterostoma Yamaguti, 1937, Sphincteristomum Oshmarin, Mamaev & Parukhin, 1961 and Megacreadium Nagaty, 1956. The Postporinae comprises only Postporus. A key to subfamilies and genera of the Apocreadiidae is provided. It is argued that there is no convincing basis for the recognition of the genus Apocreadium Manter, 1937 and all its constituent species are combined with Homalometron. The following new combinations are proposed for species previously recognised within Apocreadium: Homalometron balistis (Manter, 1947), H. caballeroi (Bravo-Hollis, 1953), H. cryptum (Overstreet, 1969), H. longisinosum (Manter, 1937), H. manteri (Overstreet, 1970), H. mexicanum (Manter, 1937) and H. vinodae (Ahmad, 1985). Apocreadium uroproctoferum Sogandares-Bernal, 1959 is found to lack a uroproct and is made a synonym of H. mexicanum. Homalometron verrunculi nom. nov. is proposed to replace the secondarily pre-occupied H. caballeroi Lamothe-Argumedo, 1965. Barbulostomum is made a synonym of Homalometron and H. cupuloris (Ramsey, 1965) n. comb. is proposed. Neochoanodera is made a synonym of Choanodera and Choanodera ghanensis (Fischthal & Thomas, 1970) n. comb. is proposed. Species within the Apocreadiinae and Postporinae are reviewed and the following are recorded or described from Australian fishes: Homalometron wrightae n. sp. from Achlyopa nigra (Macleay), H. synagris (Yamaguti, 1953) n. comb. from Scolopsis monogramma (Cuvier), H. stradbrokensis n. sp. from Gerres subfasciatus Cuvier, Marsupioacetabulum opallioderma n. sp. from G. subfasciatus, Neoapocreadium karwarensis (Hafeezullah, 1970) n. comb. from G. subfasciatus, N. splendens n. sp. from S. monogramma and Callohelmis pichelinae n. g., n. sp. from Hemigymnus melapterus (Bloch), H. fasciatus (Bloch), Stethojulis bandanensis (Bleeker) andChoerodon venustus (De Vis). Callohelmis is recognised by the combination of absence of tegumental spines, caeca terminating midway between the testes and posterior end of body, ventral sucker enclosed in a tegumental pouch, prominent muscles radiating through the body from the ventral sucker, vitelline follicles not extending into the forebody, and a very short excretory vesicle that opens ventrally. New combinations for species previously recognised within Crassicutis are proposed as follows: Neoapocreadium caranxi (Bilqees, 1976) n. comb., N. gerridis (Nahhas & Cable, 1964) n. comb., N. imtiazi (Ahmad, 1984) n. comb. and N. marina (Manter, 1947) n. comb. The host-specificity and zoogeography of the Apocreadiinae are considered.

The status of the Diplosentidae (Acanthocephala : Palaeacanthocephala) and a new family of acanthocephalans from Australian wrasses (Pisces : Labridae)

The status and composition of the Diplosentidae Tubangui et Masilungan, 1937 are reviewed. The type species of the type genus, Diplosentis amphacanthi Tubangui et Masilungan, 1937 from Siganus canaliculatus (Park, 1797) in the Philippines, is concluded to have been described inaccurately,in supposedly possessing, only two cement glands and lemnisci enclosed in a membranous sac. The species is almost certainly very close to species of Neorhadinorhynchus yamaguti, 1939 and Sclerocollum Schmidt of Paperna, 1978 which have also been reported from siganids from the tropical Indo-Pacific. Species of these genera have four cement glands and unexceptional lemnisci. As a result, Diplosentis Tubangui et Masilungan, 1937 is best considered to have affinities with the Cavisomidae Meyer, 1932. The Cavisomidae has priority over the Diplosentidae; thus the Diplosentidae becomes a synonym of the Cavisomidae. Neorhadinorhynchus and Sclerocollum are considered synonyms of Diplosentis. The affinities of the other species and genera formerly included in the Diplosentidae (other species of Diplosentis, Allorhadinorhynchus Yamaguti, 1959, Amapacanthus Salgado-Maldonado et Santos, 2000, Pararhadinorhynchus Johnston et Edmonds, 1947, Golvanorhynchus Noronha, do Fabio et Pinto, 1978 and Slendrorhynchus Amin et Soy, 1996) are discussed. It is concluded that all but Pararhadinorhynchus, two species of Diplosentis and Amapacanthus can be accommodated elsewhere satisfactorily. A new family, Transvenidae, is proposed for a small group of acanthocephalans that genuinely possess only two cement glands. Transvena annulospinosa gen. n., sp. n. is described from the labrids Anampses neoguinaicus Bleeker, 1878 (type host), A. geographicus Valenciennes, 1840, A. caeruleopunctatus Ruppell, 1829, Hemigymnus fasciatus (Bloch, 1792), and H. melapterus (Bloch, 1791) from the Great Barrier Reef, Queensland, Australia. Transvena gen. n. is distinguished from all other acanthocephalan genera by having a combination of a single ring of small spines on its trunk near or at the junction between the neck and trunk, two cement glands, a double-walled proboscis receptacle and hooks which decrease in length from the apex to the base of the proboscis. A second new genus within the Transvenidae, Trajectura, is proposed for T. perinsolens sp. n. from Anampses neoguinaicus, also from the Great Barrier Reef. Trajectura gen. n. is distinguished by the possession of only two cement glands and an anterior conical projection (function unknown) on the females. Diplosentis ikedai Machida, 1992 shares these characters and is recombined as Trajectura ikedai comb. n. Pararhadinorhynchus is transferred to the Transvenidae and Diplosentis manteri Gupta et Fatma, 1979 is recombined as Pararhadinorhynchus manteri comb. n.

Monostephanostomum georgianum n. sp (Digenea : Acanthocolpidae) from Arripis georgianus (Valenciennes) (Perciformes : Arripidae) off Kangaroo Island, South Australia, with comments on Monostephanostomum Kruse, 1979 and Stephanostomum Looss, 1899

Monostephanostomum georgianum n. sp. is described from Arripis georgianus off Kangaroo Island, South Australia. It differs from its congeners by the presence of a short second row of oral spines. M. manteri Kruse, 1979 is reported from A. georgianus off southern Western Australia and Kangaroo Island, South Australia and A. trutta off northern Tasmania. It is considered that the other two species, M. yamagutii Ramadan, 1984 and M. krusei Reimer, 1983, should probably be removed from this genus. Two new combinations are formed, M. gazzae (Shen, 1990) n. comb. (from Stephanostomum) and M. mesospinosum (Madhavi, 1976) n. comb. (from Stephanostomum). A key to the four recognised species of Monostephanostomum is given.

Life cycle evolution in the Digenea: a new perspective from phylogeny

We use a new molecular phylogeny, developed from small and large subunit ribosomal RNA genes, to explore evolution of the digenean life cycle. Our approach is to map character states on the phylogeny and then use parsimony to infer how the character evolved. We conclude that, plesiomorphically, digenean miracidia hatched from eggs and penetrated gastropod first intermediate hosts externally. Fork-tailed cercariae were produced in rediae and emerged from the snail to be eaten directly by the teleost definitive host. These plesiomorphic characters are seen in extant Bivesiculidae. We infer that external encystment and the use of second intermediate hosts are derived from this behaviour and that second intermediate hosts have been adopted repeatedly. Tetrapod definitive hosts have also been adopted repeatedly. The new phylogeny proposes a basal dichotomy between 'Diplostomida' (Diplostomoidea, Schistosomatoidea and Brachylaimoidea) and 'Plagiorchiida' (all other digeneans). There is no evidence for coevolution between these clades and groups of gastropods. The most primitive life cycles are seen in basal Plagiorchiida. Basal Diplostomida have three-host life cycles and are associated with tetrapods. The blood flukes (Schistosomatoidea) are inferred to have derived their two-host life cycles by abbreviating three-host cycles. Diplostomida have no adult stages in fishes except by life cycle abbreviation. We present and test a radical hypothesis that the blood-fluke cycle is plesiomorphic within the Diplostomida.

Sôbre uma nova espécie do gênero Lecithochirium Luehe, 1901: (Trematoda, Hemiuroidea)

In this paper a new species of the genus Lecithochirium Luehe, 1901, is described. To simplify the study of this genus, we divided it in 3 groups according principally to the relation among the suckers. L. manteri sp. n., comes nearest to L. texanum, L. priacanthi, and L. microstomum, but differes mainly from them by the great size of the suckers, pharynx and eggs.

Contribuição para o conhecimento dos parasitos de peixes do litoral do Estado da Guanabara - parte II

No presente trabalho os autores criam uma nova espécie para o gênero Lecithochirium Luehe, 1901, ficando no 3º grupo de distribuição de Freitas & Gomes (1971), mais se aproximando de L. manteri Freitas & Gomes, 1971, distinguindo-se principalmente por possuir saco genital aberto, vesícula ejaculadora externa ausente, vesícula seminal trilobada e ovos maiores. Apresentam Promatomus saltatrix (L.) como novohospedador para Parahemiurus merus (Linton, 1910) Yamaguti, 1938 ressaltando as variações encontradas nas medidas. Para Acanthocollaritrema umbilicatum Trav., Freitas e Bührnheim, 1965, acusam a presença do gonotil, e por esta razão acham que provavelmente Acanthocollaritrematinae Trav., Freitas e bührnheim, 1965, deva pertencer à família Cryptogonimidae Ciurea, 1933. Referem ainda a presença de Bucephalopsis callicotyle Kohn, 1962, Microcotyle pomatomi Goto, 1899 (polistomata) e larvas de Trypanorhyncha Diesing, 1863 (Cestoda0, em Pomatomus saltatrix (L.).

Contribuição ao conhecimento das espécies do subgênero Lepidapedon (Lepidapedoides) Yamaguti 1970: (Trematoda, Lepidapedinae)

Os autores, no presente trabalho, fazem um estudo da posição sistemática das espécies do subgênero Lepidapedon (Lepidapedoides) Yamaguti, 1970, sendo o mesmo referido pela primeira vez no Brasil. Transferem para este subgênero: L. hancocki Manter, 1940; L. longevesiculum Hafeezullah, 1970 e L. manteri Hafeezullah, 1970. Consideram L. ghanensis Fischthal & Thomas, 1970 sinônimo de L. holocentri Siddiqi & Cable, 1960. Apresentam uma chave de classificação para as espécies pertencentes á Lepidapedon (Lepidapedoides) Yamaguti, 1970. Descrevem e figuram L. (L.) epinepheli Bravo-Hollis & Manter, 1957 em novo hospedeiro.

Schikhobalotrema solitaria sp. n. and S. acanthuri Yamaguti, 1970 (Haplosplanchnidae: Digenea) in Brazilian marine fishes

Schikhobalotrema solitaria sp. n. is described from Stephanolepis hispidus (Linnaeus, 1758), and is characterized by the relation between oral sucker and pharynx 1:1,1. This Relation in the other species ranges between 1:0.3-0.6. It is more similar to S. manteri Siddiqi & Cable, 1960 in the distribution of vitellaria, differing from it in the size of vitelline follicles, extension of uterus and in the size of the eggs. S. acanthuri Yamaguti, 1970 is referred for the first time in South America in Mugil liza Valenciennes, 1836 representing a new host record.

Some Aspects of the Development of Lobatostoma jungwirthi Kritscher, 1974 (Aspidogastrea) in Snails and Cichlid Fishes from Buenos Aires, Argentina

The molluscs Heleobia castellanosae and Ampullaria canaliculata and cichlid fishes were collected from an artificial pond at Tres de Febrero Park (Buenos Aires city), between June 1994 and May 1995. One hundred and eighty of 2,467 H. castellanosae examined were infected with pre-adults of Lobatostoma jungwirthi, 112 of them in concurrent infections with digeneans. L. jungwirthi was significantly more prevalent in larger snails, especially those infected with larval digeneans, but the prevalence of infection did not fluctuate significantly throughout the year. A. canaliculata and cichlids smaller than 10 cm were not infected, but larger Cichlasoma facetum harboured adults of L. jungwirthi in their intestines. Experimental infections of C. facetum and Gymnogeophagus meridionalis with pre-adult aspidogastreans obtained from H. castellanosae were successful. The development of L. jungwirthi in the snail host involves five arbitrary growth phases. Its life-cycle is heteroxenous, similar to that described for L. manteri, with H. castellanosae as the intermediate host and cichlid fishes as the definitive host in this pond.

Caballerocotyla lenti n. sp., a capsalid monogenean from Auxis thazard (Scombridae) from off the southeastern coast of Brazil

Caballerocotyla lenti n. sp. (Monogenea: Capsalidae), recovered from the gills of Auxis thazard (Lacépède) captured off the coast of Rio de Janeiro, Brazil, is described using light and scanning electron microscopy. The new species is characterized by: a tegument with 2-5 rows of dorso-marginal, unicuspid spines; 53-54 round testes; a constricted pharynx with numerous papillae on its border; and a haptor with a plicate marginal border, a central polygonal area and seven complete septa. C. manteri (Price, 1951) and C. gouri Chauhan, 1953 sensu Murugesh (1995) are figured and commented upon.

Gorgocephalus yaaji n. sp (Digenea : Gorgocephalidae) from the brassy chub Kyphosus vaigiensis (Perciformes : Kyphosidae) off Lizard Island, northern Great Barrier Reef and further records of G-kyphosi

A new species Gorgocephalus yaaji is described in the intestine of Kyphosus vaigiensis from the waters off Lizard Island, Queensland, Australia. It differs from Gorgocephalus kyphosi by its broader body shape, the extension of the vitellarium into the forebody, a relatively longer forebody, cirrus-sac and post-caecal region, and a shorter distance between the ventral sucker and the ovary. It differs from Gorgocephalus manteri in its size, its tandem testes, and the ratios of width, ventral sucker to ovary distance and ovary to testes distance to body-length. Gorgocephalus kyphosi is reported in the pyloric caeca of K. vaigiensis from waters off Moorea, French Polynesia, and Lizard Island, Queensland, Australia. Measurements and an illustration are given of the latter species.