New plagioporines (Digenea: Opecoelidae) from deep-sea fishes of the North Atlantic Ocean

Three new species of digenean are described from demersal fishes taken in deep waters of the northwestern and northeastern Atlantic Ocean: Podocotyle schistotesticulata n. sp. from Antimora rostrata; P. harrisae n. sp. from Coryphaenoides (Lionurus) carapinus; and Gaevskajatrema halosauropsi n. sp. from Halosauropsis macrochir. The status of the nominal species of the genus Podocotyle Dujardin, 1845 is presented in annotated summary, along with a tabulation of the distinctive characteristics of recognised species of the genus. Gaevskajatrema Gibson & Bray, 1982 is discussed and its diagnosis amended.     

Lepidapedon spp. (Digenea: Lepocreadiidae) from deep-sea gadiform fishes of the NW Atlantic Ocean,including four new species

Five species are described from fishes in deep waters of the northwestern Atlantic Ocean: Lepidapedon gaevskayae n. sp. from Coryphaenoides (Nematonurus) armatus; L. merretti n. sp. from Phycis chesteri; L. zubchenkoi n. sp. from Coryphaenoides (Chalinura) leptolepis; L. beveridgei n. sp. from C. (N.) armatus; and Lepidapedon sp. innom. from Antimora rostrata. The genus Lepidapedon is discussed and divided into groups of species distinguished by the vitelline distribution and the extent of excretory vesicle. The new species are placed in their appropriate groups and differentiated from the other species in the group.     

Eight species of Lintonium Stunkard & Nigrelli, 1930 (Digenea: Fellodistomidae) in Australian tetraodontiform fishes

Systematic Parasitology - We report eight species of Lintonium from tetraodontiform fishes from Australian waters and describe six of them as new. Two species are described from tetraodontids from...     

Myxozoa of deep-sea fishes in the northwestern Atlantic

The gall bladder of 5 species of deep-water fishes (Coryphaenoides armatus, Coryphaenoides rupestris, Macrourus berglax, Antimora rostrata, and Synaphobranchus kaupi) from the New York Bight and Carson Canyon areas in the northwest Atlantic were examined for myxozoan parasites. Myxidium coryphaenoidium was found in 4 fish species, whereas Auerbachia pulchra and Ceratomyxa sp. were each observed in 1 fish species. Prevalence of myxozoan infections was greater in fishes taken off the New York Bight than from the Carson Canyon.     

The Acanthocolpidae (Digenea) of fishes from the north-east Atlantic: the status of Neophasis Stafford, 1904 (Digenea) and a study of North Atlantic forms

The genus Neophasis is defined. The taxonomic status of the genus is discussed in the light of its life-cycle, hosts and cercarial and adult morphology. It is considered to be closest to the family Acanthocolpidae due to the utilisation of a fish second intermediate host, the form of the cercarial excretory system and, in the adult, the presence of a uterine seminal receptacle and the absence of an external seminal vesicle. The taxonomic value of morphological features are discussed and a key to the north Atlantic species given. The following species are described: Neophasis oculatus (Levinsen) from Myoxocephalus scorpius off West Greenland (type-material), Norway and Denmark, Lycodes esmarkii off NW Scotland and the Faroes, and L. vahli off Newfoundland; N. burti n. sp. (distinguished from N. oculatus by sucker-ratio and testicular configuration) from Myoxocephalus octodecemspinosus off Nova Scotia (type-locality) and New Brunswick, also? immature in Gadus morhua from the Gulf of St. Lawrence; N. anarrhichae (Nicoll) from Anarhichas lupus in the North Sea and off the Faroes; and N. pusilla Stafford from A. lupus off ‘eastern Canada’ (type-material) and Nova Scotia. The only other species in the genus is N. symmetrorchis Machida from the NW Pacific Ocean.     

Proctophantastes brayi, n. sp. (Digenea: Zoogonidae) parasite of the deep-sea fish Polymixia Lowe, 1838 from Vanuatu

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 m. 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, P. gillissi, P. 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.     

Lecithostaphylus retroflexus (Molin, 1859) (Zoogonidae) and Tergestia acanthocephala (Stossich, 1887) (Fellodistomidae) (Digenea) from the epipelagic teleost Belone belone (L.) in the western Mediterranean

Numerous individuals of the poorly known species Lecithostaphylus retroflexus (Zoogonidae) and Tergestia acanthocephala (Fellodistomidae) have been recovered from the teleost fish Belone belone gracilis from off the Scandola Nature Reserve, Western Mediterranean. They are redescribed, incorporating previously undescribed features: for L. retroflexus, a post-oral ring, a bipartite seminal vesicle, the shape of the excretory vesicle, the subterminal excretory pore and the flask-shaped gland-cells associated with the distinctly pedunculate ventral sucker; and for T. acanthocephala, the intestinal bifurcation in the forebody, necessitating its return to the genus Tergestia from Theledera. Additionally, T. acanthocephala is compared with T. laticollis from various species of Trachurus from the same geographical area.     

Zoogonidae (Digenea) from southern Great Barrier Reef fishes with a description of Steganoderma (Lecithostaphylus) gibsoni n. sp.

Two species of the Zoogonidae are recorded from Heron Island on the southern Great Barrier Reef. Steganoderma (Lecithostaphylus) gibsoni n. sp. is described from the intestine of Abudefduf whitleyi (Pomacentridae). The new species is distinguished by the combination of the following: pedunculate ventral sucker, caeca extending well past testes, presence of two-chambered internal seminal vesicle, vitelline follicles extending only to anterior margin of testes, and testes close to ventral sucker. Zoogonus pagrosomi Yamaguti, 1939 is recorded from Lethrinus atkinsoni (Lethrinidae). This species has been recorded previously only from a sparid from Japan. A new combination, Steganoderma (Lecithostaphylus) fugus (Zhang, Qiu & Li, 1986), is made.     

Abyssotrema pritchardae gen. et sp. n. (Digenea: Fellodistomidae) from the deep-sea fish, Alepocephalus agassizi Goode and Bean 1883.

Abyssotrema pritchardae gen. et sp. n. is described from the benthic teleost, Alepocephalus agassizi Goode and Bean 1883 (Alepocephalidae), taken from Hudson Canyon in the western North Atlantic. The new genus is placed in the subfamily Monascinae Dollfus 1947 and relationships among Abyssotrema, Elopsium Fischthal and Thomas 1972, and Monascus Looss 1907 are discussed.     

Early post-metamorphic ontogenesis of deep-sea spatangoids (Echinoidea, Spatangoida) of the NE Atlantic Ocean

Abstract. The early juvenile development of 3 species of irregular deep-sea echinoids of the NE Atlantic was examined using scanning electron microscopy. Although the post-metamorphic development of these 3 spatangoids is very similar, the morphology and development of fascioles (specialized bands of heavily ciliated minute spines) facilitates distinguishing the species. In Hemiaster expergitus and Spatangus raschi , the fascioles present in the early juvenile develop to form adult fascioles. In Brissopsis lyrifera , a juvenile fasciole of unknown function disappears during ontogenesis, and new adult subanal and periproct fascioles arise. Fascioles of S. raschi and B. lyrifera are present at a very early stage of development (∼0.7 mm test length), whereas in H. expergitus the fasciole appears much later (∼3 mm test length). Animals smaller than 0.8 mm test diameter have not yet developed a functional mouth and are still considered as endotrophic postlarval stages. Mouth development is similar for all spatangoids examined.     

Genetic differences within and between species of deep-sea crabs (chaceon) from the North Atlantic Ocean

The deep-sea red crab Chaceon quinquedens is a commercially important crustacean on the Atlantic continental shelf and slope of North America. To assess genetic subdivision in C. quinquedens, we examined the nucleotide sequence of the mitochondrial 16S rDNA gene and the internal transcribed spacers (ITS) of the nuclear ribosomal repeat in samples from southern New England and the Gulf of Mexico. We compared those data to sequences from two congeners, a sympatric species from the Florida coast, C. fenneri, and an allopatric eastern Atlantic species, C. affinis. The 16S rDNA data consisted of 379 aligned nucleotides obtained from 37 individuals. The greatest genetic difference among geographical groups or nominal species was between C. quinquedens from southern New England and C. quinquedens from the Gulf of Mexico. Haplotypes from these two groups had a minimum of 10 differences. All 11 C. fenneri samples matched the most common haplotype found in C. quinquedens from the Gulf of Mexico, and this haplotype was not detected in C. quinquedens from southern New England. The three haplotypes of C. affinis were unique to that recognized species, but those haplotypes differed only slightly from those of C. fenneri and C. quinquedens from the Gulf of Mexico. Based on 16S rDNA and ITS data, genetic differences between C. quinquedens from southern New England and the Gulf of Mexico are large enough to conclude that these are different fishery stocks. Our results also indicate that the designation of morphological species within the commercially important genus Chaceon is not congruent with evolutionary history. The genetic similarity of C. affinis from the eastern Atlantic and C. quinquedens from the Gulf of Mexico suggests these trans-Atlantic taxa share a more recent common history than the two populations of "C. quinquedens" that we examined.     

Postlarval development in shallow and deep-sea ophiuroids (Echinodermata: Ophiuroidea) of the NE Atlantic Ocean

The postlarval phase is an essential period in the life history of marine invertebrates; vulnerable to high mortality, it ultimately influences the distribution and abundance of adult populations. In the deep NE Atlantic, a large number of posdarval ophiuroids have been found during certain times of the year, but their identification is difficult. The present work describes the ontogenesis of 12 post-metamorphic shallow-water or deep-sea ophiuroids from samples collected during the Biofar and Rockall Trough Programmes in the NE Atlantic Ocean. Analysis of the posdarval development reveals that species can be identified from a very early post-metamorphic phase using particular morphological characters. The ontogeny of homologous structures reveals similarities within related groups. However, at the same time, these structures give rise to different adult structures in different taxa. Data on the postlarval development of Ophiura qffinis suggest that this species is more closely related to the genus Ophiocten and a change in generic status is proposed.     

Merlucciotrema praeclarum (Manter, 1934) (Digenea: Hemiuridae) redescribed from myctophiform and gadiform fishes of the North Atlantic

Merlucciotrema praeclarum (Manter, 1934) is redescribed from the deep-sea benthic fishes Bathysaurus mollis, B. ferox and Cataetyx laticeps from various localities in the northern Atlantic Ocean. The genus is close to Plerurus Looss, 1907, but is retained on the basis of the presence of a muscular sinus-organ and, possibly, a rudimentary or degenerate sinus-sac. The subfamily Plerurinae Gibson & Bray, 1979 and the genus Merlucciotrema are redefined.     

Parasite infections (Trematoda, Digenea) of Sagitta friderici (Chaetognatha) from the southwestern Atlantic Ocean: prevalence and distribution

The following chaetognaths were found in the Atlantic Ocean between 34 to 40 degrees S and 52 degrees 20' to 62 degrees 00' W: Sagitta friderici, S. tasmanica, S. minima, S. gazellae, and S. enflata (in order of abundance). Of these, only S. friderici was parasitised by unencysted metacercariae of the families Derogenidae (Derogenes sp.), Hemiuridae (Ectenurus sp.) and Fellodistomidae (Monascus filiformis), and encysted metacercariae of Lepocreadiidae. The percentage of infection for each sampling station varied from 0.033 to 0.001 in August and from 0.02 to 0.001 in October 1996, with the highest values occurring at stations closer to the coast. The intensity of infection (worms per host) varied from 1 to 3 for Ectenurus sp. and was 1 for Derogenes sp., Monascus filiformis and Lepocreadiidae. Unencysted metacercariae were found in mature developmental stages of chaetognaths, whereas encysted ones occurred mainly in juveniles. The size and length of the ovaries of parasitised and unparasitised chaetognaths did not differ significantly. This is the first report of encysted Lepocreadiidae metacercariae and a progenetic metacercaria of Ectenurus sp. in Chaetognatha from the SW Atlantic Ocean.     

The Lepocreadiidae (Digenea) of fishes from the north-east Atlantic: a review of the genusLepidapedon Stafford, 1904

The genusLepidapedon is subdivided into several species groups and subgroups of species based on the vitelline distribution and the length of the excretory vesicle. The species in each of the subgroups are listed and keys to the species in most subgroups are given. The following north-eastern Atlantic species are described or redescribed:Lepidapedon rachion fromMelanogrammus aeglefinus, Gadus morhua, Aspitrigla cuculus, Merlangius merlangus andPollachius pollachius; L. cambrensis fromEnchelyopus cimbrius; L. sommervillae n. sp. fromTrachyrincus scabrus, T. murrayi andCoryphaenoides guentheri; L. elongatum fromGadus morhua; L. gaevskayae fromCoryphaenoides (Nematonurus) armatus; L. discoveryi n. sp. fromCoryphaenoides (Nematonurus) armatus; L. arlenae n. sp. fromTrachyrincus scabrus andT. murrayi; L. mariannae n. sp. fromGaidropsarus argentatus; Lepidapedon spp. innom (Elongatum-group) fromCoryphaenoides guentheri andCoryphaenoides (Chalinura) leptolepis; L. desclersae n. sp. fromLepidion eques; L. beveridgei fromCoryphaenoides (Nematonurus) armatus andC. (Chalinura) mediterraneus; andL. zubchenkoi fromCoryphaenoides (Chalinura) leptolepis andC. (C.) profundicolus. The phylogeny, host-specificity and zoogeography of the genus are briefly discussed.     

Hemiuridae (Digenea) from marine fishes of the southern Indian Ocean: Dinurinae,Elytrophallinae, Glomericirrinae and Plerurinae

The following species are described, figured and/or recorded from regions of the southern Indian Ocean: Dinurus longisinus from Coryphaena hippurus, Cape Province and Western Australia and immature in Carangoides gymnostethoides, Western Australia; Ectenurus trachuri from Trachurus declivis, Tasmania, Erilepturus tiegsi from Platycephalus endrachtensis, Pomatomus saltator and Arripis georgianus, Western Australia and Sphyraena novaehollandiae, Tasmania; Tubulovesicula angusticauda (with eight new synonyms) from Trachichthodes gerrardi, South Australia and Gymnothorax woodwardi, Saurida undosquamis and Argyrops spinifer, Western Australia; Elytrophalloides oatesi from Meuschenia freycineti and Aldrichetta forsteri, South Australia; Elytrophalloides humerus n. sp. from Trachinotus botla, Natal; Lecithocladium angustiovum (with four new synonyms) from Rastrelliger kanagurta, Natal; Glomericirrus amadai from Hoplostethus atlanticus, Tasmania; Plerurus digitatus (with 17 new synonyms) from Euthynnus affinis, Scomberomorus commerson, Thunnus albacares, Scomberoides commersonianus, Alectis ciliaris, Pomatomus saltator, Saurida undosquamis, Rachycentron canadum, Natal and Lichia amia and Pomatomus saltator, Cape Province and Carangoides gymnostethoides, Western Australia; Synapto-bothrium sp. from Pomatomus saltator, Western Australia.     

Faustulid trematodes (Digenea) from marine fishes of Australia

Twelve species of faustulid trematode are described or redescribed from Australian marine fishes. Bacciger lesteri Bray, 1982 and B. sprenti Bray, 1982 are redescribed from Selenotoca multifasciata from Moreton Bay. It is suggested that the original host record for these species, Mugil sp., was incorrect. The genera Discogastroides, Odontocotyle and Pseudodiscogasteroides are synonymised with Paradiscogaster. The new combinations Paradiscogaster arabi (Hafeezullah & Siddiqi, 1970), P. hainanensis (Shen, 1970), P. indicus (Srivastava, 1939), P. macrostomus (Shimazu & Kamegai, 1990), P. ostracii (Yamaguti, 1934) and P. pritchardae (Gupta & Ahmad, 1978) are proposed. Discogasteroides hawaiensis Hanson, 1955 is synonymised with P. ostracii. P. macrostomus and P. ostracii are redescribed from Ostracion meleagris and O. cubicus from the Great Barrier Reef. P. farooqii Hafeezullah & Siddiqi, 1970 is redescribed from Monodactylus argenteus from Moreton Bay. The following new species are described: P. machidai n. sp. from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef, P. dweorg n. sp. from Meuschenia galii, P. lobomyzon n. sp. from Tilodon sexfasciatus and P. habilis n. sp. from Pelates octolineatus, all from Western Australia. Antorchis pomacanthi (Hafeezullah & Siddiqi, 1970) Machida, 1975 is redescribed from Pomacanthus semicirculatus and P. sexstriatus from the Great Barrier Reef. The new combination Antorchis intermedius (Madhavi, 1975) is proposed for Parantorchis intermedius. Parayamagutia ostracionis is redescribed from O. cubicus from the Great Barrier Reef. Trigonocryptus conus is redescribed from Arothron hispidus from South-east Queensland and from A. nigropunctatus from the Great Barrier Reef. The new combination Trigonocryptus australiensis (Kurochkin, 1970) is proposed for Pseudodiscogasteroides australiensis. The Echinobrevicecinae is reduced to synonymy with the Faustulidae.     

Species of Lepidapedon Stafford, 1904 (Digenea: Lepidapedidae) from deep-sea fishes in the Western Mediterranean: molecular and morphological evidence

Systematic Parasitology - The species diversity of Lepidapedon Stafford, 1904 (Lepidapediae) in the Western Mediterranean was assessed based on samples from five deep-sea gadiform fishes collected...