Checklist of digenean trematodes reported from Indian marine fishes

This checklist summarises information on the digenean trematodes of Indian marine fishes contained in the world literature dating from 1913 to the end of 2008. Altogether more than 700 species of digeneans belonging to more than 200 genera and 32 families are recorded. For each parasite species information is provided on the host(s), geographical locality (-ies) and the published source(s). The synonymies proposed in the literature for some of the parasite species are also included. The classification follows that given in the 'Keys to the Trematoda'.     

Digenetic trematodes: quinone tanning system in eggshells

Three species of digenetic trematodes with colorless and transparent eggshells, Philophthalmus megalurus, Gorgoderina attenuata, and Megalodiscus temperatus, were compared by histochemical tests with Haematoloechus medioplexus, which has an identifiable quinone tanning system. Precursors for tanning including basic and tyrosine-rich proteins were identified histochemically in all species. Autoradiograms indicated that tyrosine was taken up after in vitro exposure of adult worms by vitelline tissue of G. attenuata and M. temperatus, but at a slower rate in the latter species. Protein synthesis inhibitor studies utilizing cycloheximide showed a reduction of tyrosine incorporation in the vitelline tissue of G. attenuata suggesting that tyrosine is incorporated into protein. Inhibition in M. temperatus was negligible, but evidence from other studies indicated absorption of cycloheximide by the adult may be minimal. Phenolase could not be found in G. attenuata and M. temperatus but was identified in P. megalurus. However, the enzyme system in the latter species seemed to be a partial one capable of oxidizing dihydroxyphenols but not monohydroxyphenols. Histochemical and solubility tests for keratin-type protein in the eggshells were inconclusive. It is suggested that positive identification of keratin as a structural protein of trematode eggshells be withheld until more reliable techniques can be employed. Possible evolutionary implications of the tanned eggshell in the Digenea are discussed.     

Two new species of lepocreadiid trematodes of marine fishes from the Taiwan Straits,China

Two new species of lepocreadiid trematodes are reported from marine fishes from the Taiwan Straits, China: Diploproctodaeum spinosus n. sp. from the intestine of Takifugu oblongus (= Fugu oblongus) and Preptetos parapristipomae n. sp. from Parapristipoma trilineatum. Diploproctodaeum spinosus differs from the known species of Diploproctodaeum, with 1 spine at the base of the ejaculatory duct. Preptetos parapristipomae is most similar to Preptetos rotto in having an entire ovary but differs from it in the sucker ratio, distribution of the uterus, position of the cirrus sac, and locality.     

Digenetic trematodes of Lebanese coast fishes: the species complexes Lepocreadium album (Stossich, 1890) and Lepocreadium pegorchis (Stossich, 1900) (Lepocreadiidae)

Trematodes belonging to the species Lepocreadium album (Stossich, 1890) and L. pegorchis (Stossich, 1900) were found in Spondyliosoma cantharus and Spicara smaris (their type-hosts, respectively) and other fishes in Lebanese waters. Morphometric variations in body-size, size and form of the pharynx, egg-size in relation to body-size, etc, according to host-species, are reported and commented upon. L. album obladae n. subsp. is erected for specimens from Oblada melanura.     

Digenetic trematodes: multiplication of the intramolluscan stages in some species is potentially unlimited

By carrying out chain-transplantations of intramolluscan stages of digeneans from infected to uninfected snails it has been demonstrated that a great number of generations of these stages can follow one another. In Echinostomatids the succession of redial generations potentially seems to be unlimited.     

Didymozoid trematodes (including new genera and species) from marine fishes of the Waltair coast,Bay of Bengal

Summary Fifteen species of didymozoid trematodes are recorded form marine fishes off the Waltair coast, Bay of Bengal, India. These include three new genera, namely, Platocystoides, Indodidymozoon and Renodidymocystis and six new species, namely, Didymozoon lobatum from Euthynnus affinis, Allodidymozoon cylindricum from Sphyraena obtusata and S. picuda, A. operculare from Sphyraena obtusata and S. picuda, Indodidymozzon platycephali from Platycephalus scaber, Renodidymocystis yamagutii from Rastrelliger kanagurta and Metanematobothrioides branchialis from Pristipomoides typus. Other species reported are: Didymocystis wedli Ariola, 1902, Coeliodidymocystis kamegaii Yamaguti, 1970, Platocystoides polyaster (Job, 1962), Neometadidymozoon polymorphis (Oshmarin & Mamaev, 1963), Lobatocystis yaito Yamaguti, 1965, Metadidymozoon branchiale Yamaguti, 1970; Allonematobothrium epinepheli Yamaguti, 1965; Gonapodasmius spilonotopteri Yamaguti, 1970 and Pseudocolocyntotrema yaito Yamaguti, 1970. Two new combinations made are: Allodidymozoon apharyngi (Job, 1961) for Didymozoon apharyngi Job, 1961 and Platocystoides polyaster (Job, 1962) for Platocystis polyaster Job, 1962.     

Helminths of shorebirds from the Texas Gulfcoast. I. Digenetic trematodes from the long-billed curlew, Numenius americanus

Trematodes found in 10 Numenius americanus from the Galveston area included Pelmatostomum americanum sp. n. (Echinostomatidae) from the intestine; Paratrema numenii gen. et sp. n. (Philophthalmidae) from the Bursa Fabricii and lower intestine; and the following previously known species, all representing new host records: Maritrema arenaria and Probolocorphye glandulosa (Microphallidae); Lyperosomum oswaldoi and L. sinuosum (Dicrocoeliidae); Cyclocoelum obscurum (Cyclocoelidae); Himasthla rhigedana (Echinostomatidae); and Parorchis acanthus (Philophthalmidae). New taxa are diagnosed and H. rhigedana is redescribed.     

Observations on five species of philometrid nematodes from marine fishes in Japan

Five species of philometrid nematodes (subfamily Philometrinae) are redescribed on the basis of newly collected materials from marine fishes from Japan. The species Philometra sciaenae Yamaguti, 1941, considered by Rasheed (1963) a synonym of P. lateolabracis (Yamaguti, 1935), is re-established as a valid species and the male of this nematode, collected from the ovary of the type-host, Argyrosomus argentatus, is described for the first time; the latter is characterised mainly by the length of equally long spicules (0.108–0.126 mm) and the length ratio of the gubernaculum and spicules (1:2.25). Other species redescribed on females include Philometra inimici Yamaguti, 1941 and P. sebastisci Yamaguti, 1941 from the ovary of their type-hosts, Inimicus japonicus and Sebastiscus marmoratus, respectively, and also Philometroides seriolae (Ishii, 1931) from the musculature of Seriola quinqueradiata (type-host), and Clavinema mariae (Layman, 1930) from the subcutaneous tissue of Pleuronectes schrenki and Acanthogobius flavimanus (a new host record). For the first time, cephalic ends of some of these species were studied under the scanning electron microscope (SEM) and the character of their cephalic papillae was described. The importance of a knowledge of male morphology for the taxonomy of philometrids is stressed.     

Biochemical and egg size evolution of freshwater fishes in the Rhinogobius brunneus complex (Pisces, Gobiidae) in Okinawa, Japan

Many colour morphs have been recognized in the Rhinogobius brunneus complex. A recent electrophoretic study has revealed that some of the colour morphs are well differentiated from each other genetically. In Okinawa, egg-size and life-history variation has been found in addition to the colour variation in this species complex. To clarify the nature of this life-history variation, gobies of a fluviatile morph with large eggs as well as three other amphidromous morphs with small eggs, inhabiting a single stream sympatrically in Okinawa, were analysed by electrophoresis and the females were also used for comparison of egg and clutch sizes. Electrophoretic data for 34 loci showed that each morph was separated by a fixed-allele difference for at least one locus, indicating that the four morphs which occurred sympatrically are reproductively isolated from each other. However, Nei's genetic distance between the fluviatile morph and one of the amphidromous morphs was much smaller (0.026) than distances among amphidromous gobies (0.323-0.480). Egg size of the former was by far the largest among the four. These results imply that speciation of the fluviatile morph accompanied by the egg-size increase has been completed rapidly without considerable genetic differentiation.     

Digenetic trematodes, Acanthatrium sp. and Lecithodendrium sp., as vectors of Neorickettsia risticii, the agent of Potomac horse fever

Neorickettsia (formerly Ehrlichia) risticii, the agent of Potomac horse fever (PHF), has been recently detected in trematode stages found in the secretions of freshwater snails and in aquatic insects. Insectivores, such as bats and birds, may serve as the definitive host of the trematode vector. To determine the definitive helminth vector, five bats (Myotis yumanensis) and three swallows (Hirundo rustica, Tachycineta bicolor) were collected from a PHF endemic location in northern California. Bats and swallows were dissected and their major organs examined for trematodes and for N. risticii DNA using a nested polymerase chain reaction (PCR) assay. Adult digenetic trematodes, Acanthatrium sp. and/or Lecithodendrium sp., were recovered from the gastrointestinal tract of all bats and from one swallow. The intestine of three bats, the spleen of two bats and one swallow as well as the liver of one swallow tested PCR positive for N. risticii. From a total of seven pools of identical digenetic trematodes collected from single hosts, two pools of Acanthatrium sp. and one pool of Lecithodendrium sp. tested PCR positive. The results of this investigation provide preliminary evidence that at least two trematodes in the family Lecithodendriidae are vectors of N. risticii. The data also suggest that bats and swallows not only act as a host for trematodes but also as a possible natural reservoir for N. risticii.     

Ocular angiostrongyliasis without meningitis symptoms in Okinawa,Japan

A 62-year-old female farmer presented with retinal detachment in her left eye, and an Angiostrongylus cantonensis worm was recovered by vitreous surgery. The case did not show typical clinical symptoms indicating meningitis, although the patient complained of a mild headache, a low-grade fever, and slight ataxia. The symptoms were treated as influenza before the onset of the retinal detachment. The present case is the first confirmed of ocular angiostrongyliasis in Japan.     

Five new didymozoid trematodes (Platyhelminthes, Digenea) from Australian platycephalid fishes

Five new didymozoid trematodes are described from two species of platycephalid fish collected in Moreton Bay. Australia. Indodidymozoon moretonensis sp. n. from the buccal cavity and branchial arches and 1. suttiei sp. n. from the flesh are described from Platycephalus fuscus. Indodidymozoon lesteri sp. n. from the belly skin. I. pearsoni sp. n. from the eye, and Helicodidymozoon tortor gen. n., sp. n. from the buccal cavity. branchial arches and operculum are described from Platycephalus endrachtensis. The taxonomic composition of the genus Didymozoon is discussed. Five species. D. branchiale. D. brevicolle, D. koti, D. musculi and D. Platycephali are moved to Indodidymozoon ; the generic diagnosis of Indodidymozoon is revised. One species. D. spirale , and one species from Neometadidymozoon, N. helicis. are moved to the newly creeted Helicodidymozoon. Helicodidymozoon differs from Didymozoon, Indodidymozoon and metadidymozoon in the structure of the hindbody which is spirally twisted.     

Distribution of marine birnavirus (MABV) in marine organisms from Okinawa,Japan, and a unique sequence variation of the VP2/NS region

Distribution of marine type of Aquabirnavirus (MABV) was examined in shellfish and fish from Okinawa and Ishigaki Islands, Japan, where water temperature is higher than 25°C through the year. Genome detection and virus isolation were performed for shellfish and fish samples, and the results revealed the prevalent distribution of MABV in diverse species in the area, although isolation was not frequently. Detection rate of MABV genome in bivalves was higher than gastropods, which was similar result to former report in mainland of Japan. Furthermore, the unique five-nucleotide deletion was found with a high rate of occurrence in the MABV genome from shellfish and fish. This study showed distribution status of MABV in organisms in subtropical waters by wide monitoring, and discovered new genome variation in VP2/NS region of this virus.     

DNA barcoding is a useful tool for the identification of marine fishes from Japan

In this study, 229 DNA sequences of cytochrome oxidase subunit I gene (COI) from 158 marine fishes of Japan were employed to test the efficacy of species identification by DNA barcoding. The average genetic distance was 60-fold higher between species than within species, as Kimura two parameter (K2P) genetic distances averaged 17.6% among congeners and only 0.3% among conspecifics. There were no overlaps between intraspecific and interspecific K2P distances, and all sequences formed species units in the neighbor-joining dendrogram. Hybridization phenomena in two species (Kyphosus vaigiensis and Pterocaesio digramma) were also detected through searches in Barcode of Life Data Systems (BOLD). DNA barcoding provides a new way for fish identification.     

Lipids of marine cold-water fishes

The study deals with the lipid and fatty acid compositions of the muscles, gills and liver of marine fishes inhabiting cold waters (0.5–6°C) and caught in Peter the Great Bay (3 species) and Vostok Bay (2 species), as well as with the fatty acid compositions of the main phospholipids in the muscle tissues of fish from Olyutorskii Bay (4 species). The average content of phosphatidylcholine was about 60% in muscles and in the liver and 53.8% of the sum of all phospholipids in gills. The phosphatidylethanolamine content was on the average 24.3, 25.1 and 22.3% in muscles, liver and gills, respectively. Increased contents of phosphatidylserine and sphingomyeline were recorded in the gills. The mean (S.D.) molar ratios of cholesterol/phospholipids were 0.20, 0.32, and 0.58 in the muscles, liver, and gills, respectively. It was established that phosphatidylcholine has a higher content of saturated fatty acids, whereas phosphatidylethanolamine was richer in monoenic acids and docosahexaenoic acid (DHA). It was noted that the level of polyenic fatty acids was increasing and the level of monoenic and saturated acids was decreasing in the series from gills-liver-muscles. The species with a more active mode of life were distinguished by an increased content of docosahexaenoic acid.