Biomedical subjects

L Euzet

Publications and source records attributed to L Euzet.

At least 19 recordsLinked to original sources

PubMed2006

Description de deux nouvelles espèces de Lamellodiscus Johnston & Tiegs, 1922 (Monogenea: Diplectanidae) du groupe morphologique 'ignoratus', parasites de Diplodus sargus et D. vulgaris (Teleostei: Sparidae).

The study of the diplectanid gill parasites of Diplodus Rafinesque (Teleostei: Sparidae) from off the Algerian coast revealed the presence of several species of Lamellodiscus Johnston & Tiegs, 1922 on D. sargus (Linnaeus) and D. vulgaris (Geoffroy Saint-Hilaire). Some of these species differ from the others by having a copulatory organ "en lyre" and lamellodiscs of the morphological group 'ignoratus' of Oliver (1987). In Lamellodiscus, the subgroup 'ignoratus', proposed by Amine & Euzet (2005), characterised by a simple lateral dorsal bar, includes L. ignoratus Palombi, 1943 and L. fraternus Bychowsky, 1957. Two new species, L. falcus n. sp. and L. neifari n. sp. form part of the 'ignoratus' subgroup. These species are distinguished by the morphology and the size of the sclerotised parts of the haptor and copulatory organ.

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PubMed2006

[Lamellodiscus sanfilippoi n. sp. (Monogenea, Diplectanidae) parasite from the gills of Diplodus sargus (Teleostei, Sparidae) in Mediterranean Sea].

Lamellodiscus sanfilippoi n. sp. takes place, among the other species of Lamellodiscus, in the "ergensi" sub-group (Amine et Euzet, 2005) characterized by the morphology of the dorsal lateral bars of the haptor. This sub-group comprises, in the Mediterranean, L. ergensi Euzet and Oliver, 1966, L. kechemirae Amine and Euzet, 2005, L. tomentosus Amine and Euzet, 2005, all parasite of Diplodus sargus, and L. baeri Oliver, 1974 parasite of Pagrus pagrus. L. sanfilippoi can be distinguished from the previous species by the morphology and size of the dorsal lateral bars. The new species is close to Lamellodiscus furcillatus Kritsky, Jiménez-Ruiz and Sey, 2000, a parasite of Diplodus noct in the Persian Gulf, but differs by the size of the haptoral sclerotised pieces and the morphology of the male copulatory apparatus. Lamellodiscus gussevi Sanfilippo (1978) et Lamellodiscus abbreviatus Sanfilippo (1978) are considered as nomina nuda.

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PubMed2005

[In progress citation].

During a study of the gill parasites (Monogenea) of two species of Diplodus Rafinesque (Sparidae), D. sargus (Linnaeus) and D. vulgaris (Geoffroy Saint-Hilaire) from off the Algerian coast, several species of the family Diplectanidae Bychowsky, 1957 and genus Lamellodiscus Johnston & Tiegs, 1922 were collected. We present a redescription of L. ergensi Euzet & Oliver, 1966 and describe two new species, L. kechemirae n. sp. and L. tomentosus n. sp. These new species are close to L. ergensi but differ in the morphology and size of both the haptoral sclerites and the male genital system. On the basis of the dorsal lateral bars of the haptor, we suggest the recognition within the group 'ignoratus' of Oliver (1987) of two subgroups, 'ignoratus' (sensu stricto), with simple dorsal bars, and 'ergensi', with complex bars which are more or less divided in two parts. We also present a redescription of L. baeri Oliver, 1974, collected from the sparid Pagrus pagrus (Linnaeus) (the type-host) and allocate it to the 'ergensi' subgroup. All of these species of Lamellodiscus are reported from sparids off the Algerian coasts for the first time.

Algeria↗

PubMed2005

[Monogenean parasites from Clariidae (Teleostei, Siluriformes) in Cameroon: I. Description of two new species of Gyrodactylus from the Nyong basin].

The study of gill and skin parasites of three fishes species belonging to the genus Clarias: C. camerunensis, C. jaensis and C. pachynema, from the Nyong basin (Cameroon), revealed the presence of two new Monogenean species of the genus Gyrodactylus Nordmann: G. camerunensis n. sp. and G. nyongensis n. sp. parasite of Clarias camerunensis, C. jaensis and C. pachynema. Gyrodactylus camerunensis n. sp. is clearly distinguished from G. nyongensis n. sp. by the smaller size of the haptor sclerites. These two new species differ also from their closest African relatives of the genus Gyrodactylus, G. rysavyi, G. clarii and G. alberti, by the morphology and size of the haptorail sclerites. Their host specificity was discussed and appeared stenoxenous (mesostenoxenous).

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PubMed2004

Eutetrarhynchid cestodes from Atlantic and Mediterranean elasmobranch fishes, with the description of two new species of Dollfusiella Campbell & Beveridge, 1994 and redescriptions of Prochristianella papillifer (Poyarkoff, 1909) Dollfus, 1957 and Parachristianella trygonis Dollfus, 1946.

Dollfusiella elongata n. sp. is described from the spiral valves of Rhinobatos rhinobatos (Linnaeus) and R. cemiculus Geoffroy St-Hilaire off the coast of Tunisia, while D. aculeata n. sp. is described from the spiral valves of Dasyatis pastinaca (Linnaeus) off the western coast of France, Dasyatis tortonesei Capape off the coast of Tunisia and Dasyatis chrysonota (Smith) var. marmorata off the coast of Senegal. A redescription of Dollfusiella spinifer (Dollfus, 1969) Campbell & Beveridge, 1994 is included based on the type-specimens from Myliobatis aquila (Linnaeus) from the Mediterranean coast of France. Prochristianella papillifer (Poyarkoff, 1909) Dollfus, 1957 is redescribed from specimens from Dasyatis pastinaca off Tunisia and the scolex and mature segments are described for the first time. Parachristianella trygonis Dollfus, 1946 is redescribed from Dasyatis pastinaca off the coast of France and Dasyatis tortonesei off Tunisia, with the mature and gravid segments being described for the first time. Parachristianella monomegacantha Kruse, 1959 is reported for the first time from the elasmobranchs Dasyatis pastinaca , Myliobatis aquila , Rhinobatos cemiculus and R. rhinobatos . Definitions of the related genera Dollfusiella Campbell & Beveridge, 1994 and Prochristianella Dollfus, 1946 are revised. Prochristianella spinulifera Beveridge & Jones, 2000 is transferred to Dollfusiella as D. spinulifera n. comb. New combinations proposed formally for the first time are: D. aetobati (Beveridge, 1990) n. comb., D. bareldsi (Beveridge, 1990) n. comb., D. lineata (Linton, 1909) n. comb., D. litocephalus (Heinz & Dailey, 1974) n. comb., D. macrotrachelus (Heinz & Dailey, 1974) n. comb., D. michiae (Southwell, 1929) n. comb., D. musteli (Carvajal, 1974) n. comb., D. schmidti (Heinz & Dailey, 1974) n. comb. and D. vooreemi (Sao Clemente & Gomes, 1989) n. comb. The type-specimens of Prochristianella tenuispinis (Linton, 1890) Dollfus, 1946 were re-examined and the species is transferred to Dollfusiella as D. tenuispinis (Linton, 1890) n. comb. Features of known species of Dollfusiella are presented in tabular form.

Africa↗

PubMed2004

Monogeneans from Pangasiidae (Siluriformes) in Southeast Asia: VI. Pangasitrema camillae n. g., n. sp. (Monogenea, Ancylodiscoididae), from Pangasius polyuranodon.

The examination of gill parasites from Pangasius polyuranodon Bleeker, 1852 (Siluriformes, Pangasiidae) in Indonesia revealed the presence of a new species of Manogenea, belonging to a new genus: Pangasitrema camillae n. g., n. sp. (Ancylodiscoididae). Among Ancylodiscoididae, the genus has several distinguishing features: the reduced size of the haptor, the morphology and size of gripi, the absence of a ventral transversal bar and of a cuneus associated with dorsal gripi.

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PubMed2004

Two new species of Cichlidogyrus Paperna, 1960 (Monogenea, ancyrocephalidae) gill parasites on Hemichromis fasciatus (Pisces, Cichlidae) in Africa, with remarks on parasite geographical distribution.

The examination of gill parasites from Hemichromis fasciatus Peters, 1858 (Pisces, Cichlidae) in Africa revealed the presence of nine species of Monogenea, three belong to Onchobdella Paperna, 1968 and the others to Cichlidogyrus Paperna, 1960. Seven have been previously described (O. aframae Paperna, 1968; O. bopeleti Bilong Bilong & Euzet, 1995; O. voltensis Paperna, 1968; C. dageti Dossou & Birgi, 1984; C. euzeti Dossou & Birgi, 1984; C. falcifer Dossou & Birgi, 1984 and C. longicirrus Paperna, 1965); two, belonging to the latter genus, are considered as new species: C. sanseoi n. sp. and C. teugelsi n. sp. As parasitic species are not present in all the host distribution area, we think that H. fasciatus is made up of two distinct populations (or even sister species).

Africa, Western↗

PubMed2004

Five new species of Pedibothrium (Tetraphyllidea: Onchobothriidae) from the tawny nurse shark, Nebrius ferrugineus, in the Pacific Ocean.

The spiral intestines of 7 Tawny nurse sharks (Nebrius ferrugineus; Rhincodontidae) from Australia and French Polynesia were examined for tapeworms. These sharks hosted 5 new species of Pedibothrium. The 5 species were prepared for light and scanning electron microscopy. Whereas 3 of the species exhibit the bipronged hooks typical of members of Pedibothrium, 1 species was found to possess tiny unipronged hooks or to lack some, or all, hooks, and all individuals of the fifth species appeared to lack bothridial hooks entirely. Nonetheless, the otherwise remarkable similarities between these species and the species of Pedibothrium bearing bipronged hooks were considered to be sufficient to justify the placement of these 2 species in this genus. All 5 species possess proglottid features typical of Pedibothrium, including a uterus that extends anteriorly only to the level of the cirrus sac and a cirrus sac that is bent anteriorly and is crossed by the vagina. All 5 species also exhibit uniloculated bothridia. Of particular note was the fact that all 5 species exhibit bladelike spinitrichs with elongated distal tips, a form of microthrix currently known only from species of Pedibothrium. As a consequence, these species were treated as possessing modified hooks or as having lost hooks. The diagnoses of Pedibothrium and Onchobothriidae were emended to include these species. Each of the 5 new species bears a strong resemblance to 1 or more species of Pedibothrium hosted by a species of rhincodontid shark other than N. ferrugineus. Much of Southwell's type and voucher material of Pedibothrium was located and used to verify the identity of Pedibothrium kerkhami and many of the hosts from which Southwell's material of Pedibothrium was collected. This material suggests that P. kerkhami parasitizes Stegostoma fasciatum and not N. ferrugineus.

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PubMed2003

[Description of Scalithrium n. gen. (Cestoda, Tetraphyllidea) with Scalithrium minimum (Van Beneden, 1850) n. comb., a parasite of Dasyatis pastinaca (Elasmobranchii, Dasyatidae), as type species].

Scalithrium gen. n. (Cestoda, Tetraphyllidea) is proposed with Scalithrium minimum (Van Beneden, 1850) n. comb., parasite of Dasyatis pastinaca (Elasmobranchii, Dasyatidae) as type-species. The new genus Scalithrium (Tetraphyllidea, Phyllobothriidae, Rhinebothriinae) is erected for several species previously included in the genus Rhinebothrium. These species have a scolex with four bothridia, the distal surface of which is divided by transverse septa in a single row of loculi. Scalithrium minimum (Van Beneden, 1850) n. comb. is redescribed from specimens collected from the type-host Dasyatis pastinaca in Tunisia and becomes the type-species of the new genus. After Braun (1900) Echeneibothrium variabile Van Beneden, 1850 is considered as type-species of the genus Echeneibothrium. Species of Rhinebothriinae to be transferred into the genus Scalithrium are discussed and a key is proposed for the eight species.

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PubMed2001

Two new species of Macrobothridium (Cestoda: Diphyllidea) from rhinobatid elasmobranchs in the Gulf of Gabès, Tunisia, with notes on the status of the genus.

As a result of an investigation of metazoan parasites of elasmobranch fishes in the Gulf of Gabès, Tunisia, we discovered 2 new species of diphyllidean cestodes. Macrobothridium euterpes n. sp. is described from the spiral intestine of Rhinobatos rhinobatos, and Macrobothridium syrtensis n. sp. from the spiral intestine of Rhinobatos cemiculus. Macrobothridium euterpes is distinguished from the only other species in the genus (Macrobothridium rhynchobati) by the number of rostellar hooks, size, genital pore position, vagina position, and ovary shape. Macrobothridium syrtensis is distinguished from M. rhynchobati by the hook morphology, testis number, and overall size, and from M. euterpes by the number of rostellar hooks, testis number, genital pore position, vagina position, and ovary shape. These are the first 2 species added to the genus since its establishment in 1989. A standardized formula for representing the number and arrangement of rostellar hooks in diphyllidean species is presented.

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PubMed2000

New species of the Monocotylidae (Monogenea) from the stingray Dasyatis tortonesi Capapé (Euselachii, Dasyatidae) off the Tunisian coast, with comments on host-specificity and the specific identities of Mediterranean stingrays.

Heterocotyle capapei n. sp. and Thaumatocotyle tunisiensis n. sp. are described from the gills and the nasal cavity, respectively, of Dasyatis tortonesi collected from the Tunisian coast. H. capapei is distinguished from other species in the genus by the morphology of the penis, which is conical and has a long narrow distal point. T. tunisiensis differs from all known species of Thaumatocotyle by the shape and size of the penis. The host Dasyatis tortonesi has long been confused with D. pastinaca. Our study shows that their monogeneans are oioxenic, suggesting that D. pastinaca and D. tortonesi are distinct species. These results suggest that the monogenean parasite fauna could be used as a diagnostic tool for species identification: these parasites may, therefore, represent good biological indicators. The host-specificity of the Heterocotylinae and Merizocotylinae is discussed.

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PubMed2000

[Schilbetrematoides manizani n. sp. (Dactylogyridea) monogenean parasite of Schilbe mandibularis (Günther, 1867) (Schilbeidae) in the Ivory Coast].

The authors describe a new species in the genus Schilbetrematoides Kritsky & Kulo, 1992 from the gills of Schilbe mandibularis (Günther, 1867) (Schilbeidae) caught in the rivers Bia and Agneby in Ivory Coast. S. manizani n. sp. differs from S. pseudodactylogyrus Kritsky & Kulo, 1992, a parasite of Schilbe intermedius Rüppell, 1832 by having morphologically distinct gripi.

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PubMed2000

A new species of Ditrachybothridium (Cestoda: Diphyllidea) from Galeus sp. (Selachii, Scyliorhynidae) from the south Pacific Ocean, with a revision of the diagnosis of the order, family, and genus and notes on descriptive terminology of microtriches.

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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PubMed1999

Seven new species of Quadriacanthus Paperna, 1961 (Monogenea) from the gills of Heterobranchus longifilis and H. isopterus from the Ivory Coast, west Africa.

The gills of two species of Siluriformes, Heterobranchus longifilis and H. isopterus collected from the Rivers Agnéby and Bia in the Ivory Coast (West Africa) revealed the presence of seven new species of Quadriacanthus Paperna, 1961 (Monogenea: Ancyrocephalidae). The following parasites are described: Quadriacanthus longifilisi n. sp., Q. thysi n. sp., Q. ayameensis n. sp., Q. agnebiensis n. sp., Q. simplex n. sp., Q. gourenei n. sp. and Q. macrocirrus n. sp.

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PubMed1999

[Myliocotyle pteromylaei gn. and sp. n. (Monogenea, Monocotylidae) gill parasite of Pteromylaeus bovinus (Euselachii, Myliobatidae) in Tunisia].

Fifteen specimens of Pteromylaeus bovinus (Geoffroy St. Hilaire) from the Tunisian coast were examined for ectoparasites during 1996-1998. Myliocotyle pteromylaei gn. et sp. n. found on gills of twelve host specimens is described and illustrated. It differs from other Heterocotylinae mainly by the number and morphology of haptoral dorsal structures, arrangement and number of the anterior glands and morphology of the penis. M. pteromylaei, along with Heliocotyle kartasi, illustrates the originality of monocotylids gill parasites of Pteromylaeus bovinus.

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PubMed1999

New species of Spinuris (monogenea: monocotyladae) from Zapteryx exasperata (elasmobranchii: rhinobatidae) from Baja California Sur, Mexico.

Monocotylid monogeneans were collected from the gills of 2 Rhinobatos productus and 5 Zapteryx exasperata in Bahia Almeja, Baja California Sur, Mexico. All are parasitized by monocotylids of the genus Spinuris, 9 specimens of Spinuris lophosoma Doran on Rhinobatos productus (new record) and 27 specimens of Spinuris zapterygis n. sp. on Z. exasperata. This new species differs from the other species in the genus Spinuris by the number of dorsal haptoral sclerites, morphology of hooks, and male copulatory apparatus. The generic diagnosis of the genus Spinuris is revised.

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PubMed1998

The selection of habitats among the monogenea.

The pressures responsible for the selection of "non-ectoparasitic" habitats in the Monogenea are discussed. It is suggested that certain monogeneans have become internal to reduce the pressures exerted by predators of ectoparasites rather than to avoid competition with other ectoparasites or to have access to better resources. The fact that these movements have concerned the Monopisthocotylea rather than the Polyopisthocotylea could be related to the different mode of invasion by oncomiracidia in these two groups. When Monogenea are internal in "non-fish" hosts, it is suggested that this has allowed them to survive the colonisation of terrestrial environments by vertebrates, a process of coevolution which was disturbed by lateral transfers.

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PubMed1997

Analysis of Calliobothrium (Tetraphyllidea:Onchobothriidae) with descriptions of three new species and erection of a new genus.

Examination of voucher or type material, or both, of 9 of the 10 currently recognized species of Calliobothrium resulted in redescriptions of C. evani, C. lintoni, and C. pellucidum, and emendations of the descriptions of C. eschrichti and C. leuckarti. New collections of Calliobothrium from the spiral intestines of Mustelus spp. led to the discovery of 3 new species: Calliobothrium hayhowi n. sp. from Mustelus antarcticus in Australia, Calliobothrium riseri n sp. from Mustelus henlei in the Sea of Cortéz, México, and Calliobothrium violae n. sp. from Mustelus canis in the Northwestern Atlantic Ocean. New collections of C. evani from the Sea of Cortéz established Mustelus lunulatus as a host for this species. Six species of Calliobothrium were examined with scanning electron microscopy. A cladistic analysis was performed on 12 of the 13 species of Calliobothrium recognized after the descriptions of the new taxa, using 34 characters and 4 outgroup taxa. This analysis yielded a single most parsimonious tree with a consistency index of 0.68. This tree suggests that Calliobothrium is monophyletic only when the biloculated species Calliobothrium pritchardae is excluded from the genus. The new genus Biloculuncus is erected to house C. pritchardae so that the monophyly of Calliobothrium can be maintained. A key to the species of onchobothriids bearing 2 pairs of hooks per bothridium is presented.

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