The invasive land flatworm Arthurdendyus triangulatus has repeated sequences in the mitogenome, extra-long cox2 gene and paralogous nuclear rRNA clusters.

Using a combination of short- and long-reads sequencing, we were able to sequence the complete mitochondrial genome of the invasive 'New Zealand flatworm' Arthurdendyus triangulatus (Geoplanidae, Rhynchodeminae, Caenoplanini) and its two complete paralogous nuclear rRNA gene clusters. The mitogenome has a total length of 20,309 bp and contains repetitions that includes two types of tandem-repeats that could not be solved by short-reads sequencing. We also sequenced for the first time the mitogenomes of four species of Caenoplana (Caenoplanini). A maximum likelihood phylogeny associated A. triangulatus with the other Caenoplanini but Parakontikia ventrolineata and Australopacifica atrata were rejected from the Caenoplanini and associated instead with the Rhynchodemini, with Platydemus manokwari. It was found that the mitogenomes of all species of the subfamily Rhynchodeminae share several unusual structural features, including a very long cox2 gene. This is the first time that the complete paralogous rRNA clusters, which differ in length, sequence and seemingly number of copies, were obtained for a Geoplanidae.

Morphological and molecular studies of the life-cycle stages of the monorchiid Monorchis parvus (Looss, 1902) (Digenea) from the Southern Mediterranean coast (Tunisia).

The elucidation of life-cycles of digeneans, with their successive larval stages, is facilitated by the use of molecular markers. Samples of sporocysts containing cercariae and metacercariae belonging to Monorchis Monticelli, 1893 were collected from naturally infected bivalves, Cerastoderma glaucum (Bruguière, 1789), and adult forms of Monorchis spp. were collected from sparid fishes of the genus Diplodus. All specimens were collected in the Gulf of Gabès, southern Tunisia. The identities of the examined molluscs and fishes were determined via molecular barcoding of their COI gene. Sequences of COI and ITS1 genes were also obtained for both larval and adult stages of collected parasite specimens. Genetic sequence data generated for the collected larval specimens only differed minimally from the sequence data of adults identified as Monorchis parvus; we attribute the difference to intraspecific variation. The morpho-anatomical study showed that the different stages of M. parvus collected from the Tunisian coasts had the same morphology as those reported in European waters with a lag in maturity and lower measurements. The species is recorded and molecularly characterised for the first time off the Tunisian coasts.

Rediscovery of Bipalium admarginatum de Beauchamp, 1933 (Platyhelminthes, Tricladida, Geoplanidae) in Malaysia, with molecular characterisation including the mitogenome.

We present here the first observation of Bipalium admarginatum de Beauchamp, 1933 since its original description 90 years ago. Three specimens were found on Perhentian Kecil Island, off Terengganu State, Malaysia and photographed in the field, and two were collected. This report thus includes the first colour photographs published for this species, from a locality close to the type-locality, Tioman Island (which is ca. 200 km south of the locality in this study, on the east coast of Peninsula Malaysia). We describe the external morphology and colour pattern of the species, which correspond well to the original description, itself based only on two preserved specimens. We performed an in-depth molecular characterisation of the species, including its complete mitochondrial genome, the 18S sequence and elongation 1-alpha (EF1-α) sequence. In addition, EF1-α sequences were also retrieved for 5 additional geoplanid species. No tRNA-Thr could be detected in the mitogenome of B. admarginatum, a lack already reported in several species of geoplanids, but we found a 13 bp sequence that contains the anticodon loop and seems to be conserved among geoplanids and might thus possibly represent a non-canonical undetected tRNA. We discuss the difficulties encountered in trying to reconstruct the cluster of nuclear ribosomal genes, a problem already mentioned for other Triclads. Three phylogenies, based respectively on all mitochondrial proteins, 18S, and EF1-α, were computed; the position of B. admarginatum within the Bipaliinae was confirmed in each tree, as sister-group to various bipaliine species according to the sequences available for each tree. In the mitochondrial proteins tree, which had high support, B. admarginatum was sister to Bipalium kewense and Diversibipalium multilineatum.

Morphological and molecular characterisation of Tristoma integrum Diesing, 1850 (Monogenea, Capsalidae), including its complete mitogenome.

Capsalids are monopisthocotylean monogenean parasites found on the skin and gills of fish. Capsalines (subfamily Capsalinae) are large-sized capsalids, parasitic on highly prized gamefish, and species of Tristoma parasitise only the gills of swordfish (Xiphias gladius). We obtained specimens of Tristoma integrum Diesing, 1850 from swordfish collected off Algeria in the Mediterranean Sea. Here, we describe the specimens, including the key systematics characters of dorsolateral body sclerites. One specimen was used for a next generation sequencing analysis but a part of it, including the sclerites, was mounted on a permanent slide, drawn, and deposited in a curated collection. We characterised the complete mitogenome, the ribosomal cluster (including 18S and 28S) and additional genes such as Elongation factor 1 alpha (EF1α) and Histone 3. We also retrieved molecular information from the host tissue present in the gut of the monogenean and provide the sequence of the complete rRNA cluster of the host, X. gladius. The mitogenome of T. integrum is 13 968 bp in length and codes for 12 protein, 2 rRNA and 22 tRNA. Phylogenies of capsalids were generated from 28S sequences and concatenated mitochondrial protein-coding genes, respectively. In the 28S phylogeny, most subfamilies based on morphology were not found to be monophyletic, but the Capsalinae were monophyletic. In both phylogenies, the closest member to Tristoma spp. was a member of the Capsaloides. In an Appendix, we report the complex nomenclatural history of Tristoma Cuvier, 1817 and its species.

Title: Caractérisation morphologique et moléculaire de Tristoma integrum Diesing, 1850 (Monogenea, Capsalidae) y compris son mitogénome complet. Abstract: Les Capsalidae sont des monogènes Monopisthocotylea parasites de la peau et des branchies des poissons. Les Capsalinae sont des Capsalidae de grande taille qui parasitent les poissons de pêche sportive, très prisés, et les espèces de Tristoma ne parasitent que les branchies de l'espadon (Xiphias gladius). Nous avons obtenu des spécimens de Tristoma integrum Diesing, 1850 à partir d'espadons collectés au large de l'Algérie en Méditerranée. Nous décrivons les spécimens, y compris les caractères systématiques clés des sclérites dorsolatéraux du corps. Un spécimen a été utilisé pour une analyse de séquençage de nouvelle génération, mais une partie de celui-ci, qui comprend des sclérites, a été montée sur une lame permanente, dessinée et déposée dans une collection. Nous avons caractérisé le mitogénome complet, le cluster ribosomal (y compris 18S et 28S) et des gènes supplémentaires tels que le facteur d'élongation 1 alpha (EF1α) et histone 3. Nous avons également récupéré des informations moléculaires à partir du tissu de l'hôte présent dans l'intestin du monogène et fournissons la séquence du cluster d'ARNr complet de l'hôte, X. gladius. Le mitogénome de T. integrum a une longueur de 13 968 pb et code pour 12 gènes de protéines, 2 ARNr et 22 ARNt. Des phylogénies des Capsalidae ont été générées, respectivement à partir des séquences 28S et des gènes codant pour les protéines mitochondriales concaténés. Dans la phylogénie 28S, la plupart des sous-familles basées sur la morphologie n'ont pas été trouvées monophylétiques, à l'exception notable des Capsalinae. Dans les deux phylogénies, les membres les plus proches de Tristoma spp. étaient des espèces de Capsaloides. Dans une annexe, nous rapportons l'histoire nomenclaturale complexe de Tristoma Cuvier, 1817 et de ses espèces.

The invasive land flatworm Obama nungara in La Runion, a French island in the Indian Ocean, the first report of the species for Africa.

The land flatworm Obama nungara, a species originating from South America and already invasive in many European countries, is recorded from La Runion, a French island in the Indian Ocean. This is the first record of O. nungara from this locality and also the first record of the species for Africa. Three specimens were collected in 2021 and 2022, in the communes of Saint Paul, Saint Joseph and Le Tampon, respectively; the three localities are widely separated, with two in the Western part and one in the South-eastern part of the island. This suggests that the species is already present in several locations in La Runion, and it is likely that the species is already present since 2020. The specimen from Saint Paul had the same cox1 haplotype as specimens previously recorded from several countries of Europe; it is hypothesized that the species was imported from Europe, probably from France. We mapped climatic suitability of the species in La Runion and found that O. nungara could potentially invade a large part of the island. One record was apparently associated with the transport of plates of travertine, a construction material which has numerous cavities thus suitable for the transport and survival of adult or cocoons of land flatworms.

Truly a hyperparasite, or simply an epibiont on a parasite? The case of Cyclocotyla bellones (Monogenea, Diclidophoridae).

Cyclocotyla bellones Otto, 1823 (Monogenea, Diclidophoridae) is one of the few monogenean species reported as hyperparasitic: the worms dwell on cymothoid isopods, themselves parasites of the buccal cavity of fishes. We present here observations based on newly collected monogenean specimens from Ceratothoa parallela (Otto, 1828), an isopod parasite of Boops boops off Algeria and also investigated its diet to address whether Cy. bellones is indeed a hyperparasite, i.e., whether it feeds on the isopod. We also compared the body shape of various monogeneans belonging to the same family as Cy. bellones, the Diclidophoridae, including Choricotyle cf. chrysophryi Van Beneden & Hesse, 1863, collected from Pagellus acarne off Algeria. No morphological character of the anterior organs suggested any special adaptation in Cy. bellones to the perforation of the crustacean cuticle. The wall of the oesophagus and of the intestine of Cy. bellones was lined with a dark pigment similar to what is usually observed in haematophagous polyopisthocotyleans, and which is derived from ingested fish blood. We noticed that an anterior elongate stem exists only in diclidophorids dwelling on parasitic isopods and never in those attached to the gills. We hypothesize that the anterior stem of the body of Cy. bellones is an anatomical adaptation for the monogenean to feed on the fish while dwelling on the isopod. We thus consider that Cy. bellones is an epibiont of the parasitic crustacean, as it uses it merely as an attachment substrate, and is not a true hyperparasite.

Title: Vraiment un hyperparasite, ou simplement un épibionte sur un parasite ? Le cas de Cyclocotyla bellones (Monogenea, Diclidophoridae). Abstract: Cyclocotyla bellones Otto, 1823 (Monogenea, Diclidophoridae) est l'une des rares espèces de monogènes signalées comme hyperparasites : les vers vivent sur des isopodes cymothoïdes, eux-mêmes parasites de la cavité buccale des poissons. Nous présentons ici des observations basées sur des spécimens de monogènes nouvellement collectés de Ceratothoa parallela (Otto, 1828), un isopode parasite de Boops boops au large de l'Algérie et avons également étudié son régime alimentaire pour déterminer si Cy. bellones est bien un hyperparasite (c'est-à-dire, se nourrit-il de l'isopode ?). Nous avons également comparé la morphologie de divers monogènes appartenant à la même famille que Cy. bellones, les Diclidophoridae, dont Choricotyle cf. chrysophryi Van Beneden & Hesse, 1863, collecté sur Pagellus acarne au large de l'Algérie. Aucun caractère morphologique des organes antérieurs ne suggérait d'adaptation particulière à la perforation de la cuticule des crustacés chez Cy. bellones. La paroi de l'œsophage et de l'intestin de Cy. bellones était tapissée d'un pigment foncé semblable à ce que l'on observe habituellement chez les Polyopisthocotylea hématophages, et qui est issu du sang de poisson ingéré. Nous avons remarqué qu'une partie allongée antérieure n'existe que chez les Diclidophoridae vivant sur des isopodes parasites et jamais chez ceux attachés aux branchies. Nous émettons l'hypothèse que la partie antérieure du corps de Cy. bellones est une adaptation anatomique permettant au monogène de se nourrir du poisson tout en vivant sur l'isopode. Nous considérons donc que Cy. bellones est un épibionte du crustacé parasite, puisqu'il ne l'utilise que comme substrat pour son attachement, et n'est pas un véritable hyperparasite.

Redescription, complete mitochondrial genome and phylogenetic relationships of Hexostoma thynni (Delaroche, 1811) Rafinesque, 1815 (Monogenea, Hexostomatidae).

Specimens of Hexostoma thynni (Delaroche, 1811) Rafinesque, 1815 were collected from their type-host, the bluefin tuna Thunnus thynnus, caught off Algeria, i.e. close to the type-locality, off Mallorca, which is also in the Mediterranean. The species is briefly redescribed and compared to previous descriptions, under the same name or as its synonym Plagiopeltis duplicata Diesing, 1858, to ascertain identity of specimens. The three genera within the Hexostomatidae (Hexostoma Rafinesque, 1815, Neohexostoma Price, 1961 and Homostoma Unnithan, 1965) are briefly discussed, with comments on the fragility of characters used to distinguish them. Using next-generation sequencing, the complete mitogenome and the cluster of ribosomal genes (SSU, LSU, ITS1, ITS2, 5.8S) were obtained. The mitogenome is 14,649 bp long and codes for 12 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes; its size is similar to other mitogenomes obtained from polyopisthocotylean monogeneans. A phylogeny based on concatenated mitogenome protein-coding genes from nine species of polyopisthocotylean monogeneans produced a tree in which the Hexostomatidae H. thynni was associated with other Mazocraeidea, such as Chauhaneidae and Diclidophoridae. This invalidates the hypothesis of Boeger & Kritsky (1993) of Hexostomatidae as sister-group to the Mazocraeidea and suggests the demise of the suborder Hexostomatinea Boeger & Kritsky, 1993. We insist on the usefulness of depositing parts of specimens used for molecular analyses, prepared on permanent slides, in a curated collection.

Title: Redescription, génome mitochondrial complet et relations phylogénétiques d'Hexostoma thynni (Delaroche, 1811) Rafinesque, 1815 (Monogenea, Hexostomatidae). Abstract: Des spécimens d'Hexostoma thynni (Delaroche, 1811) Rafinesque, 1815 ont été collectés sur leur hôte-type, le thon rouge Thunnus thynnus, capturé au large de l'Algérie, c'est-à-dire près de la localité-type, au large de Majorque, qui se trouve également en Méditerranée. L'espèce est brièvement redécrite et comparée aux descriptions précédentes, sous le même nom ou sous son synonyme Plagiopeltis duplicata Diesing, 1858, pour vérifier l'identité des spécimens. Les trois genres au sein des Hexostomatidae (Hexostoma Rafinesque, 1815, Neohexostoma Price, 1961 et Homostoma Unnithan, 1965) sont brièvement discutés, avec des commentaires sur la fragilité des caractères utilisés pour les distinguer. En utilisant le séquençage de nouvelle génération, le mitogénome complet et le groupe de gènes ribosomiques (SSU, LSU, ITS1, ITS2, 5.8S) ont été obtenus. Le mitogénome a une longueur de 14 649 pb et code pour 12 gènes codant pour des protéines, 2 gènes d'ARN ribosomal et 22 gènes d'ARN de transfert, et sa taille est similaire à celle des autres mitogénomes obtenus de monogènes Polyopisthocotylea. Une phylogénie basée sur les gènes codant pour les protéines concaténées du mitogénome de 9 espèces de monogènes Polyopisthocotylea a produit un arbre dans lequel l'Hexostomatidae H. thynni était associé à d'autres Mazocraeidea tels que les Chauhaneidae et les Diclidophoridae. Ceci réfute l'hypothèse de Boeger & Kritsky (1993) des Hexostomatidae comme groupe-frère des Mazocraeidea et suggère la disparition du sous-ordre Hexostomatinea Boeger & Kritsky, 1993. Nous insistons sur l'intérêt de déposer dans une collection entretenue des parties des spécimens utilisées pour les analyses moléculaires, préparées sur des lames microscopiques permanentes.

A world of taxonomic pain: cryptic species, inexplicable host-specificity, and host-induced morphological variation among species of Bivesicula Yamaguti, 1934 (Trematoda: Bivesiculidae) from Indo-Pacific Holocentridae, Muraenidae and Serranidae.

The taxonomy of species of Bivesicula Yamaguti, 1934 is analysed for samples from holocentrid, muraenid and serranid fishes from Japan, Ningaloo Reef (Western Australia), the Great Barrier Reef (Queensland), New Caledonia and French Polynesia. Analysis of three genetic markers (cox1 mtDNA, ITS2 and 28S rDNA) identifies three strongly supported clades of species and suggests that Bivesicula as presently recognized is not monophyletic. On the basis of combined morphological, molecular and biological data, 10 species are distinguished of which five are proposed as new. Bivesicula Clade 1 comprises seven species of which three are effectively morphologically cryptic relative to each other; all seven infect serranids and four also infect holocentrids. Bivesicula Clade 2 comprises three species of which two are effectively morphologically cryptic relative to each other; all three infect serranids and one also infects a muraenid. Bivesicula Clade 3 comprises two known species from apogonids and a pomacentrid, and forms a clade with species of Paucivitellosus Coil, Reid & Kuntz, 1965 to the exclusion of other Bivesicula species. Taxonomy in this genus is made challenging by the combination of low resolving power of ribosomal markers, the existence of regional cox1 mtDNA populations, exceptional and unpredictable host-specificity and geographical distribution, and significant host-induced morphological variation.

Hammerhead flatworms (Platyhelminthes, Geoplanidae, Bipaliinae): mitochondrial genomes and description of two new species from France, Italy, and Mayotte.

BACKGROUND: New records of alien land planarians are regularly reported worldwide, and some correspond to undescribed species of unknown geographic origin. The description of new species of land planarians (Geoplanidae) should classically be based on both external morphology and histology of anatomical structures, especially the copulatory organs, ideally with the addition of molecular data. METHODS: Here, we describe the morphology and reproductive anatomy of a species previously reported as Diversibipalium "black", and the morphology of a species previously reported as Diversibipalium "blue". Based on next generation sequencing, we obtained the complete mitogenome of five species of Bipaliinae, including these two species. RESULTS: The new species Humbertium covidum n. sp. (syn: Diversibipalium "black" of Justine et al., 2018) is formally described on the basis of morphology, histology and mitogenome, and is assigned to Humbertium on the basis of its reproductive anatomy. The type-locality is Casier, Italy, and other localities are in the Department of Pyrénées-Atlantiques, France; some published or unpublished records suggest that this species might also be present in Russia, China, and Japan. The mitogenomic polymorphism of two geographically distinct specimens (Italy vs France) is described; the cox1 gene displayed 2.25% difference. The new species Diversibipalium mayottensis n. sp. (syn: Diversibipalium "blue" of Justine et al., 2018) is formally described on the basis of external morphology and complete mitogenome and is assigned to Diversibipalium on the basis of an absence of information on its reproductive anatomy. The type- and only known locality is the island of Mayotte in the Mozambique Channel off Africa. Phylogenies of bipaliine geoplanids were constructed on the basis of SSU, LSU, mitochondrial proteins and concatenated sequences of cox1, SSU and LSU. In all four phylogenies, D. mayottensis was the sister-group to all the other bipaliines. With the exception of D. multilineatum which could not be circularised, the complete mitogenomes of B. kewense, B. vagum, B. adventitium, H. covidum and D. mayottensis were colinear. The 16S gene in all bipaliine species was problematic because usual tools were unable to locate its exact position. CONCLUSION: Next generation sequencing, which can provide complete mitochondrial genomes as well as traditionally used genes such as SSU, LSU and cox1, is a powerful tool for delineating and describing species of Bipaliinae when the reproductive structure cannot be studied, which is sometimes the case of asexually reproducing invasive species. The unexpected position of the new species D. mayottensis as sister-group to all other Bipaliinae in all phylogenetic analyses suggests that the species could belong to a new genus, yet to be described.

A revision of Plectanocotyle (Monogenea, Plectanocotylidae), with molecular barcoding of three species and the description of a new species from the streaked gurnard Chelidonichthys lastoviza off Algeria.

BACKGROUND: The family Plectanocotylidae includes parasites of the gills of marine fish; although nine genera and about 20 species have been described, almost no molecular information is available. Putting aside Plectanocotyle elliptica Diesing, 1850, supposedly a parasite of the white perch Morone americana, never found again since its original description, two species were valid within Plectanocotyle Diesing, 1850 before this work: Plectanocotyle gurnardi (Van Beneden & Hesse, 1863) Llewellyn, 1941 and Plectanocotyle major Boudaya, Neifar & Euzet, 2006. METHODS: In this paper, we describe the third species of the genus Plectanocotyle and perform a comparative morphological and molecular analysis of the three species and of Triglicola obscura (Euzet & Suriano, 1974) Mamaev, 1976. Host fishes were also barcoded (COI) for confirmation of host identifications. RESULTS: Plectanocotyle lastovizae n. sp. is described from the gills of the streaked gurnard Chelidonichthys lastoviza collected off Algeria. The species is compared with specimens of Plectanocotyle cf. gurnardi (from C. lastoviza) from the same locality and P. major and T. obscura (both from the longfin gurnard C. obscurus). Molecules from Plectanocotyle cf. gurnardi could not be compared with P. gurnardi from the type-host and type-locality and we kept the status of the Mediterranean specimens as pending. Algeria is a new geographic record for P. major and T. obscura. Plectanocotyle lastovizae n. sp. is distinguished from the other species found in the Mediterranean by the measurements of clamps, number of testes, and COI sequences, with notable divergence (7.8-11.8%) from the other two species of the genus. DISCUSSION: We briefly present a list of currently known members of the family Plectanocotylidae, their biology and their hosts.

The complete mitogenome of the potentially invasive flatworm Australopacificaatrata (Platyhelminthes, Geoplanidae) displays unusual features common to other Rhynchodeminae.

We sequenced the complete mitochondrial genome of the flatworm Australopacificaatrata. The species, originally described from New South Wales, Australia, has been found in various locations in the British Isles, New Zealand and in the United States of America; it is thus potentially invasive. The genome is 16513 bp long, encodes for 12 protein coding genes, two ribosomal RNA genes and 20 tRNA genes, and is completely colinear with the other two available Rhynchodeminae. In addition, it shares with them some unusual characters discriminating them from members of the other subfamilies of Geoplanidae, the most noticeable being the extra length of its cox2 gene. The data allow a reliable multigene phylogeny to be derived, and also provide a means of accurate biomonitoring of possible invasiveness by A.atrata.

Echinocephalus inserratus sp. n. (Nematoda: Gnathostomatidae) from the stingray Pastinachus ater (Dasyatidae) and new records of congeneric and some other nematode larvae from teleost fishes off New Caledonia.

Based on light and electron microscopical studies, a new nematode parasite, Echinocephalus inserratus sp. n. (Spirurida: Gnathostomatidae), is described from the spiral valve of the broad cowtail stingray Pastinachus ater (Macleay) (Dasyatidae, Myliobatiformes) from off New Caledonia. The new species is morphologically and biometrically most similar to Echinocephalus overstreeti Deardorff et Ko, 1983, differing from it mainly in the absence of serrations on the posterior parts of pseudolabia and on interlabia, and in having a longer gubernaculum (150-299 µm long). Morphologically unidentifiable, mostly encapsulated larvae of Echinocephalus spp. were recorded from the following six species of teleost fishes collected in New Caledonian waters, serving as paratenic hosts: Perciformes: Acanthopagrus berda (Forsskål) (Sparidae) and Nemipterus furcosus (Valenciennes) (Nemipteridae); Tetraodontiformes: Abalistes stellatus (Anonymous), Pseudobalistes fuscus (Bloch et Schneider) (both Balistidae), Lagocephalus sceleratus (Gmelin) (Tetraodontidae) and Aluterus monoceros (Linnaeus) (Monacanthidae). Co-parasitising larvae of Ascarophis sp. and Hysterothylacium sp. were also collected from P. fuscus. All these findings represent new host and geographical records. A key to valid species of Echinocephalus Molin, 1858 is provided.

Triple barcoding for a hyperparasite, its parasitic host, and the host itself: a study of Cyclocotyla bellones (Monogenea) on Ceratothoa parallela (Isopoda) on Boops boops (Teleostei).

Cyclocotyla bellones Otto, 1823 (Diclidophoridae) is a monogenean characterised by an exceptional way of life. It is a hyperparasite that attaches itself to the dorsal face of isopods, themselves parasites in the buccal cavity of fishes. In this study, Cy. bellones was found on Ceratothoa parallela (Otto, 1828), a cymothoid isopod parasite of the sparid fish Boops boops off Algeria in the Mediterranean Sea. We provide, for the first time, molecular barcoding information of a hyperparasitic monogenean, the parasitic crustacean host, and the fish host, with COI sequences.

TITLE: Triple code-barre pour un hyperparasite, son hôte parasite et l'hôte lui-même : une étude de Cyclocotyla bellones (Monogenea) sur Ceratothoa parallela (Isopoda) sur Boops boops (Teleostei). ABSTRACT: Cyclocotyla bellones Otto, 1823 (Diclidophoridae) est un monogène caractérisé par un mode de vie exceptionnel. C'est un hyperparasite qui se fixe sur la face dorsale d'isopodes, eux-mêmes parasites dans la cavité buccale de poissons. Dans cette étude, Cy. bellones a été trouvé sur Ceratothoa parallela (Otto, 1828), un isopode cymothoïdé parasite du poisson sparidé Boops boops au large de l'Algérie, en mer Méditerranée. Nous fournissons, pour la première fois, des informations de codes-barres moléculaires d'un monogène hyperparasite, de l'hôte crustacé parasite et de l'hôte poisson, avec des séquences de COI.

Redescription and molecular characterization of two species of Pauciconfibula (Monogenea, Microcotylidae) from trachinid fishes in the Mediterranean Sea.

Many Pauciconfibula spp. have a long and complicated taxonomic history. The remaining unsolved taxonomic confusion in this genus is impelled by the host range and status of Pauciconfibula spp. from trachinid fishes: Pauciconfibula trachini and Pauciconfibula draconis, from Trachinus radiatus and Trachinus draco (Trachinidae), respectively. Pauciconfibula trachini was reported on Trachinus draco, type host of Pauciconfibula draconis suggesting thus a stenoxenic specificity for the former monogenean and the occurrence of two congeneric polyopisthocotyleans on a single host. Moreover, the validity of Pauciconfibula draconis was repeatedly questioned by several authors, unjustified synonymy between the two species was proposed, and the delimitations between the two species remained unsolved. Original descriptions were also incomplete and poorly illustrated. In this study, we provide a detailed illustrated redescription of both species based on newly collected specimens of Pauciconfibula trachini and Pauciconfibula draconis collected from their type hosts from off three Mediterranean localities: Algeria, Tunisia, and Italy. Integrative taxonomy using COI sequences was applied to resolve the delimitation between Pauciconfibula trachini and P. draconis. This study provides the first DNA barcoding for members of this genus.

Presence of the invasive land flatworm emPlatydemus/em emmanokwari/em (Platyhelminthes, Geoplanidae) in Guadeloupe, Martinique and Saint Martin (French West Indies).

The land flatworm Platydemus manokwari (Platyhelminthes, Geoplanidae) is recorded from the islands of Guadeloupe, Martinique, and Saint Martin in the Caribbean arc. Photographs and records were obtained mainly from citizen science and ranged from the end of 2018 to February 2021; several specimens were deposited in the collections of the Muséum National d'Histoire Naturelle in Paris, France. Thirty records were from Guadeloupe, but only one from Martinique and from Saint Martin, respectively. The COI sequences of 3 specimens from Guadeloupe show that they belong to the World haplotype also found in many countries. We also report P. manokwari from Fort Myers, Florida, USA, with molecular characterization, which was also the World haplotype. This is the first published record of P. manokwari for Guadeloupe, Martinique and Saint Martin and the second for islands in the Caribbean, after Puerto Rico.

Redescription of Ascarophis distorta Fusco et Overstreet, 1978 (Nematoda, Cystidicolidae) from the stomach of some butterflyfishes off New Caledonia.

PURPOSE: The nematode Ascarophis distorta Fusco et Overstreet, 1978 (Cystidicolidae), originally described from the butterflyfish Chaetodon paucifasciatus Ahl (Perciformes, Chaetodontidae) in the Red Sea, was established based solely on the light microscopical (LM) examination of specimens. However, the present taxonomy of cystidicolid nematodes is mostly based on details of the cephalic structures properly visible only with the use of scanning electron microscopy (SEM). METHODS: Helminthological examinations of some marine fishes from coral reefs off New Caledonia, South Pacific, carried out in the years 2003-2007, revealed the presence of A. distorta in two Chaetodon spp. and thus enabled its redescription. The nematode specimens were studied with the use of both LM and SEM. RESULTS: The specimens of A. distorta were obtained from the stomach of the threadfin butterflyfish Chaetodon auriga Forsskål and the vagabond butterflyfish Chaetodon vagabundus Linnaeus. This is just the second record of this parasite since its description 43 years ago. SEM, used in this species for the first time, revealed some taxonomically important, previously unreported or insufficiently described morphological features, such as details in the cephalic structure, the shape of deirids, structure of the distal tip of the left spicule, or the exact number and distribution of male caudal papillae. The finding of A. distorta in C. auriga and C. vagabundus off New Caledonia represents new host and geographical records. The examination of 39 specimens of butterflyfishes from off New Caledonia, belonging to 14 Chaetodon spp. and 3 Heniochus spp., revealed that the nematode was only present in the 2 fish species listed above. CONCLUSIONS: This parasite seems to be host-specific to only certain species of butterflyfishes (Chaetodon spp.), and is probably widespread in the Indo-Pacific region, as well as its hosts.

Four polyopisthocotyleans (Platyhelminthes: Monogenea) from carangid fishes in the Mediterranean, off the Algerian coasts.

Four polyopisthocotyleans were collected from the gill filaments of carangids from off the Algerian coast, southern Mediterranean. Specimens of Gastrocotyle trachuri van Beneden & Hesse, 1863 (Gastrocotylidae) and Cemocotyle cf. trachuri Dillon & Hargis, 1965 (Heteraxinidae) from the Mediterranean horse mackerel Trachurus mediterraneus (Steindachner), Zeuxapta seriolae (Meserve, 1938) (Heteraxinidae) from the greater amberjack Seriola dumerili (Risso) and Pyragraphorus hollisae Euzet & Ktari, 1970 (Pyragraphoridae) from the pompano Trachinotus ovatus (Linnaeus) are redescribed based on newly collected specimens. Their taxonomically important morphological features (male copulatory organ and clamp sclerites) are described and illustrated, and the morphometric variation between Mediterranean and oceanic specimens is highlighted. Careful examination of the specimens of Cemocotyle Sproston, 1946 from the Mediterranean revealed that they exhibited unusual features compared with Cemocotyle trachuri Dillon & Hargis, 1965 from the Pacific, mainly the absence of the terminal lappet, thus questioning previous records of this species in the Mediterranean. New geographical locality records are provided for Z. seriolae and P. hollisae. The presence of C. cf. trachuri and Z. seriolae in the Mediterranean is noteworthy as these monogeneans were initially described in the Pacific Ocean. This study extends the geographical range of Z. seriolae to the southern Mediterranean.

Complete mitogenome of the invasive land flatworm Parakontikia ventrolineata, the second Geoplanidae (Platyhelminthes) to display an unusually long cox2 gene.

We sequenced the complete mitogenome of the invasive flatworm Parakontikia ventrolineata (Platyhelminthes, order Tricladida, family Geoplanidae). The genome is 17,210 bp long, and displays common unusual characteristics shared with Platydemus manokwari, such as its colinearity, an overlap between ND4L and ND4 genes and an unusually long cox2 genes. Both Parakontikia and Platydemus are members of the subfamily Rhynchodeminae and their close relationships are supported by the maximum likelihood phylogeny inferred from the protein-coding genes.

A comparative study of the ultrastructural characteristics of the mature spermatozoa of two fellodistomids Tergestia clonacantha and T. laticollis and contribution to the phylogenetic knowledge of the Gymnophalloidea.

The ultrastructure of the mature spermatozoa of Tergestia clonacantha and T. laticollis collected from the digestive tracts of fishes from New Caledonia is described using transmission electron microscopy and compared to that of related species. The spermatozoa of the two species exhibit the general pattern described in most digeneans, namely two axonemes with the 9 + "1" pattern of the Trepaxonemata, nucleus, mitochondrion, cortical microtubules, an external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. The spermatozoa of T. clonacantha and T. laticollis show the same ultrastructural model with some specificities in each case, particularly in the disposition of the structures in the posterior extremities of the spermatozoon. This study confirms that ultrastructural characters of the mature spermatozoon are useful tools for the phylogenetic analysis of the Digenea.

TITLE: Étude comparative des caractéristiques ultrastructurales des spermatozoïdes mûrs de deux Fellodistomidae, Tergestia clonacantha et T. laticollis, et contribution à la connaissance phylogénétique des Gymnophalloidea. ABSTRACT: L'ultrastructure des spermatozoïdes mûrs de Tergestia clonacantha et T. laticollis, prélevés dans le tube digestif de poissons de Nouvelle-Calédonie, est décrite par microscopie électronique à transmission et comparée à celle d'espèces apparentées. Les spermatozoïdes des deux espèces présentent la structure générale décrite chez la plupart des digènes, à savoir deux axonèmes du type 9 + « 1 ¼ des Trepaxonemata, un noyau, une mitochondrie, des microtubules corticaux, des ornementations externes de la membrane plasmique, des corps épineux et des granules de glycogène. Les spermatozoïdes de T. clonacantha et T. laticollis présentent le même modèle ultrastructural avec quelques spécificités dans chaque cas, notamment dans la disposition des structures aux extrémités postérieures du spermatozoïde. Cette étude confirme que les caractères ultrastructuraux du spermatozoïde mûrs sont des outils utiles pour l'analyse phylogénétique des Digenea.

Redescription of Flexophora ophidii Prost & Euzet, 1962 (Monogenea: Diclidophoridae) from Ophidion barbatum (Ophidiidae) off the Algerian coast, Mediterranean Sea.

The diclidophorid Flexophora ophidii Prost & Euzet, 1962, the type- and only species of the genus Flexophora Prost & Euzet, 1962, has never been redescribed neither reported since its original description. The latest lacked a diagnosis of the genus that remains unavailable to date. Flexophora ophidii is redescribed and illustrated based on examination of new material from the type-host Ophidion barbatum L. (Ophidiiformes: Ophidiidae) collected off the Algerian coast (new geographical record), southern Mediterranean. A diagnosis of the genus is provided.