Towards the resolution of the Microcotyle erythrini species complex: description of Microcotyle isyebi n. sp. (Monogenea, Microcotylidae) from Boops boops (Teleostei, Sparidae) off the Algerian coast

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Microcotyle visa n. sp. (Monogenea: Microcotylidae), a gill parasite of Pagrus caeruleostictus (Valenciennes) (Teleostei: Sparidae) off the Algerian coast, Western Mediterranean

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Giant worms chez moi! Hammerhead flatworms (Platyhelminthes, Geoplanidae, Bipalium spp., Diversibipalium spp.) in metropolitan France and overseas French territories

Background: Species of the genera Bipalium and Diversibipalium, or bipaliines, are giants among land planarians (family Geoplanidae), reaching length of 1 m; they are also easily distinguished from other land flatworms by the characteristic hammer shape of their head. Bipaliines, which have their origin in warm parts of Asia, are invasive species, now widespread worldwide. However, the scientific literature is very scarce about the widespread repartition of these species, and their invasion in European countries has not been studied. Methods: In this paper, on the basis of a four year survey based on citizen science, which yielded observations from 1999 to 2017 and a total of 111 records, we provide information about the five species present in Metropolitan France and French overseas territories. We also investigated the molecular variability of cytochrome-oxidase 1 (COI) sequences of specimens. Results: Three species are reported from Metropolitan France: Bipalium kewense, Diversibipalium multilineatum, and an unnamed Diversibipalium 'black' species. We also report the presence of B. kewense from overseas territories, such as French Polynesia (Oceania), French Guiana (South America), the Caribbean French islands of Martinique, Guadeloupe, Saint Martin and Saint Barthelemy, and Montserrat (Central America), and La Reunion island (off South-East Africa). For B. vagum, observations include French Guiana, Guadeloupe, Martinique, Saint Barthelemy, Saint Martin, Montserrat, La Reunion, and Florida (USA). A probable new species, Diversibipalium sp. 'blue,' is reported from Mayotte Island (off South-East Africa). B. kewense, B. vagum and D. multilineatum each showed 0% variability in their COI sequences, whatever their origin, suggesting that the specimens are clonal, and that sexual reproduction is probably absent. COI barcoding was efficient in identifying species, with differences over 10% between species; this suggests that barcoding can be used in the future for identifying these invasive species. In Metropolitan south-west France, a small area located in the Department of Pyrenees-Atlantiques was found to be a hot-spot of bipaliine biodiversity and abundance for more than 20 years, probably because of the local mild weather. Discussion: The present findings strongly suggest that the species present in Metropolitan France and overseas territories should be considered invasive alien species. Our numerous records in the open in Metropolitan France raise questions: as scientists, we were amazed that these long and brightly coloured worms could escape the attention of scientists and authorities in a European developed country for such a long time; improved awareness about land planarians is certainly necessary

Obama chez moi! The invasion of metropolitan France by the land planarian Obama nungara (Platyhelminthes, Geoplanidae)

Background: Obama nungara is a species of land flatworm originating from South America; the species was recently described and distinguished from a similar species, Obama marmorata. Obama nungara has invaded several countries of Europe, but the extent of the invasion has not been thoroughly mapped. Methods: In this article, based on a five and a half-year survey undertaken by citizen science, which yielded 530 records from 2013 to 2018, we analysed information about the invasion of Metropolitan France by O. nungara. We also investigated the variability of newly obtained cytochrome c oxidase 1 (COI) sequences of specimens from France, Italy and Switzerland. Results: Obama nungara was recorded from 72 of the 96 Departments of Metropolitan France. The species is especially abundant along the Atlantic coast, from the Spanish border to Brittany, and along the Mediterranean coast, from the Spanish border to the Italian border. More than half of the records were from an altitude below 50 m, and no record was from above 500 m; mountainous regions such as the Alps, Pyrenees and Massif Central are not invaded. Local abundance can be impressive, with 100 of specimens found in a small garden. An analysis of our new COI sequences, combined with published sequences of specimens from several countries, confirmed that three clades comprise the species. The first clade, 'Brazil', is currently confined to this country in South America; the second clade, 'Argentina 2', was found in Argentina and in Europe, only in Spain; and the third, 'Argentina 1', was found in Argentina and in Europe, in Spain, Portugal, France, UK, Italy, Belgium, and Switzerland. This suggests that two clades of O. nungara from Argentina have invaded Europe, with one widely spread. Discussion: The present findings strongly suggest that O. nungara is a highly invasive species and that the population which has invaded several countries in Europe comes from Argentina. The wide dispersion of the species and its reported local abundance, combined with the predatory character of the species, make O. nungara a potential threat to the biodiversity and ecology of the native soil fauna in Europe, and probably the most threatening species of all invasive land planarians present in Europe

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

No vagina, one vagina, or multiple vaginae? An integrative study of Pseudaxine trachuri (Monogenea, Gastrocotylidae) leads to a better understanding of the systematics of Pseudaxine and related genera

The presence/absence and number of vaginae is a major characteristic for the systematics of the Monogenea. Three gastrocotylid genera share similar morphology and anatomy but are distinguished by this character: Pseudaxine Parona & Perugia, 1890 has no vagina, Allogastrocotyle Nasir & Fuentes Zambrano, 1983 has two vaginae, and Pseudaxinoides Lebedev, 1968 has multiple vaginae. In the course of a study of Pseudaxine trachuri Parona & Perugia 1890, we found specimens with structures resembling “multiple vaginae”; we compared them with specimens without vaginae in terms of both morphology and molecular characterisitics (COI barcode), and found that they belonged to the same species. We also investigated the male copulatory organ (MCO) of this species, the accuracy of the original description of which is known to be a matter of debate. We found that the genital atrium is armed with 12 hooks arranged as a single circle and a central hollow stylet which is probably involved in traumatic insemination. We redescribed Pseudaxine trachuri based on newly collected specimens from off the coast of Algeria and Museum specimens from off France. Specimens from the type-host, Trachurus trachurus, were found to be similar, for both molecular sequences and morphology, to those found on Boops boops. We can therefore confirm, for the first time with molecular evidence, that B. boops is a host of this parasite. We consider that Pseudaxinoides was erected on the basis of an erroneous interpretation of structures which are not vaginae and, consequently, propose the transfer of most of its species to Pseudaxine, as P. australis (Lebedev, 1968) n. comb., P. bychowskyi (Lebedev, 1977) n. comb., P. caballeroi (Lebedev, 1977) n. comb., P. cariacoensis (Nasir & Fuentes-Zambrano, 1983) n. comb., and P. vietnamensis (Lebedev, Parukhin & Roitman, 1970) n. comb. We also propose Allogastrocotyle dillonhargisorum nom. nov. for Pseudaxine bivaginalis Dillon & Hargis, 1965 to avoid a secondary homonymy

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

Molecular phylogenies support taxonomic revision of three species of Laurencia (Rhodomelaceae, Rhodophyta), with the description of a new genus

Systematics of the Laurencia complex was investigated using a taxon-rich data set including the chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene only and a character-rich data set combining the mitochondrial cytochrome oxidase 1 (COI-5P), the rbcL marker, and the nuclear large subunit of the ribosomal operon (LSU). Bayesian and ML analyses of these data sets showed that three species hitherto placed in the genus Laurencia were not closely related to Laurencia sensu stricto. Laurencia caspica was the sister group of the remaining Osmundea species, L. crustiformans joined Palisada and L. flexilis consisted of an independent lineage. In light of these results a new genus, Ohelopapa, was proposed to accommodate L. flexilis. This new genus is morphologically characterized by four pericentral cells in each vegetative axial segment, however it lacks corps en cerise in cortical cells and secondary pit connections between cortical cells which are characteristic in Laurencia. Three novel combinations are proposed to render the classification closer to a natural system: Ohelopapa flexilis, Osmundea caspica, and Palisada crustiformans

Polycomb Repressive Complex 2 Controls the Embryo-to-Seedling Phase Transition

Polycomb repressive complex 2 (PRC2) is a key regulator of epigenetic states catalyzing histone H3 lysine 27 trimethylation (H3K27me3), a repressive chromatin mark. PRC2 composition is conserved from humans to plants, but the function of PRC2 during the early stage of plant life is unclear beyond the fact that it is required for the development of endosperm, a nutritive tissue that supports embryo growth. Circumventing the requirement of PRC2 in endosperm allowed us to generate viable homozygous null mutants for FERTILIZATION INDEPENDENT ENDOSPERM (FIE), which is the single Arabidopsis homolog of Extra Sex Combs, an indispensable component of Drosophila and mammalian PRC2. Here we show that H3K27me3 deposition is abolished genome-wide in fie mutants demonstrating the essential function of PRC2 in placing this mark in plants as in animals. In contrast to animals, we find that PRC2 function is not required for initial body plan formation in Arabidopsis. Rather, our results show that fie mutant seeds exhibit enhanced dormancy and germination defects, indicating a deficiency in terminating the embryonic phase. After germination, fie mutant seedlings switch to generative development that is not sustained, giving rise to neoplastic, callus-like structures. Further genome-wide studies showed that only a fraction of PRC2 targets are transcriptionally activated in fie seedlings and that this activation is accompanied in only a few cases with deposition of H3K4me3, a mark associated with gene activity and considered to act antagonistically to H3K27me3. Up-regulated PRC2 target genes were found to act at different hierarchical levels from transcriptional master regulators to a wide range of downstream targets. Collectively, our findings demonstrate that PRC2-mediated regulation represents a robust system controlling developmental phase transitions, not only from vegetative phase to flowering but also especially from embryonic phase to the seedling stage

Insights into the Rare Mediterranean Endemic Kallymenia spathulata : DNA Phylogenies Resolve This Species as Halymeniaceae (Halymeniales) Rather than Kallymeniaceae (Gigartinales), with the Proposal of Felicinia spathulata comb. nov.

International audienceThe rare endemic Mediterranean alga Kallymenia spathulata was collected at Nice and Saint Raphael in June 2013 during a survey conducted along the French Mediterranean coast between Menton and Toulon (French Riviera). DNA barcode sequences (COI-5P) generated from the five collected specimens were identical and allied with Felicinia marginata, another Mediterranean endemic that is classified within the Halymeniaceae (Halymeniales) whereas the genus Kallymenia is representative of the Kallymeniaceae (Gigartinales). We further confirmed the alliance of K. spathulata with Felicinia marginata by conducting phylogenetic analyses inferred by combined genes including Cox1, rbcL and LSU. Unfortunately, none of the specimens were fertile, precluding emending the description of the reproductive anatomy of this species. In light of our phylogenies, we propose the novel combination Felicinia spathulata. The genus Felicinia now comprises two species, both endemic to the Mediterranean Se