114 research outputs found
A new species of Pista Malmgren, 1866 (Polychaeta, Terebellidae) from the north-western Mediterranean Sea
A new species of Terebellidae, Pista colini sp. n., has been identified from the harbour of Banyuls-sur-Mer, north-western Mediterranean Sea. This new species was found in very high densities, exclusively in gravelly sand deposited manually, and was not found in the original source habitat of the gravel. This species is characterized by the colour of the ventral shields with pinkish anterior part and a blood red posterior part in live specimens, a pair of unequal-sized plumose branchiae inserted on segment II and anterior thoracic neuropodia with long-handled uncini. The presence of long-handled uncini even in the smallest specimens constitutes the major difference between Pista colini sp. n. and other Pista species with a single pair of branchiae such as P. lornensis and P. bansei
An Invasive Mussel (Arcuatula senhousia, Benson 1842) Interacts with Resident Biota in Controlling Benthic Ecosystem Functioning
The invasive mussel Arcuatula senhousia has successfully colonized shallow soft sediments worldwide. This filter feeding mussel modifies sedimentary habitats while forming dense populations and efficiently contributes to nutrient cycling. In the present study, the density of A. senhousia was manipulated in intact sediment cores taken within an intertidal Zostera noltei seagrass meadow in Arcachon Bay (French Atlantic coast), where the species currently occurs at levels corresponding to an early invasion stage. It aimed at testing the effects of a future invasion on (1) bioturbation (bioirrigation and sediment mixing) as well as on (2) total benthic solute fluxes across the sedimentâwater interface. Results showed that increasing densities of A. senhousia clearly enhanced phosphate and ammonium effluxes, but conversely did not significantly affect community bioturbation rates, highlighting the ability of A. senhousia to control nutrient cycling through strong excretion rates with potential important consequences for nutrient cycling and benthicâpelagic coupling at a broader scale. However, it appears that the variability in the different measured solute fluxes were underpinned by different interactions between the manipulated density of A. senhousia and several faunal and/or environmental drivers, therefore underlining the complexity of anticipating the effects of an invasion process on ecosystem functioning within a realistic context
An Invasive Mussel (Arcuatula senhousia, Benson 1842) Interacts with Resident Biota in Controlling Benthic Ecosystem Functioning
The invasive mussel Arcuatula senhousia has successfully colonized shallow soft sediments worldwide. This filter feeding mussel modifies sedimentary habitats while forming dense populations and efficiently contributes to nutrient cycling. In the present study, the density of A. senhousia was manipulated in intact sediment cores taken within an intertidal Zostera noltei seagrass meadow in Arcachon Bay (French Atlantic coast), where the species currently occurs at levels corresponding to an early invasion stage. It aimed at testing the effects of a future invasion on (1) bioturbation (bioirrigation and sediment mixing) as well as on (2) total benthic solute fluxes across the sedimentâwater interface. Results showed that increasing densities of A. senhousia clearly enhanced phosphate and ammonium effluxes, but conversely did not significantly affect community bioturbation rates, highlighting the ability of A. senhousia to control nutrient cycling through strong excretion rates with potential important consequences for nutrient cycling and benthicâpelagic coupling at a broader scale. However, it appears that the variability in the different measured solute fluxes were underpinned by different interactions between the manipulated density of A. senhousia and several faunal and/or environmental drivers, therefore underlining the complexity of anticipating the effects of an invasion process on ecosystem functioning within a realistic context
Five new species of Terebellides (Annelida, Polychaeta, Trichobranchidae) from Papua New Guinea (Bismarck and Solomon seas)
Five new species of Terebellides are described from coastal and deep waters of Papua New Guinea, using both morphology and molecular tools (for four species). Terebellides elenae n. sp. is characterized by the absence of both a glandular lateral region on TC3 and papillae on margins of the branchial lamellae and by the presence of partially fused branchial lobes with conspicuous fifth lobe and dorsal rounded projections until TC6. Terebellides fauchaldi n. sp. has a very large glandular lateral region on the third thoracic chaetiger (TC3), a fifth branchial lobe and partially fused branchial lobes, and conspicuous dorsal rounded projections on TC2â6. Terebellides madeep n. sp. is characterized by a thin glandular region on TC3 and by four free branchial lobes. Terebellides oculata n. sp. is one of the only two species in the world to have eyespots. Finally, T. papillosa n. sp. has geniculate chaetae on TC6 and TC7 and bears a large number of papillae. A majority-rule consensus tree using the 16S gene and an identification key for all Terebellides species described from the Central Indo-Pacific region are provided
Confirmation of the exotic status of Marphysa victori Lavesque, Daffe, BonifĂĄcio & Hutchings, 2017 (Annelida) in French waters and synonymy of Marphysa bulla Liu, Hutchings & Kupriyanova, 2018
The bait worm Marphysa victori Lavesque, Daffe, BonifĂĄcio & Hutchings, 2017
was originally described from Arcachon Bay, France. In the original description,
the authors suggested that it may have been introduced, although definitive
evidence was lacking at the time. In this paper, we confirm that M. victori is an
exotic species originating from East Asia, probably a native of China or Japan. This
species was most likely introduced into Arcachon Bay in the 1970s with non-native
oysters Crassostrea gigas Thunberg, 1793. The Asiatic origin of this species is
confirmed based on both morphological and molecular evidence. Comparison of
the type specimens of M. victori with those of Marphysa bulla Liu, Hutchings &
Kupriyanova, 2018 described from the Yellow Sea, China, showed no morphological
or molecular differences and therefore the more recently named M. bulla is
relegated to a junior synonym. This is the first example of a large-sized errant
invertebrate species being introduced with oysters into Arcachon Bay.Initiative d'excellence de l'Université de Bordeau
Recent discovery of Paranthura japonica Richardson, 1909 (Crustacea: Isopod: Paranthuridae) in European marine waters (Arcachon Bay, Bay of Biscay)
The Asiatic isopod Paranthura japonica Richardson, 1909 was collected in 2007 in Arcachon Bay (SW France), where the species occurs in a variety of habitats, both in the intertidal and at shallow depths. This species, native to the Sea of Japan, may have been accidentally introduced in Arcachon Bay with oyster transfers or as fouling on ship hulls
Revision of spaghetti worms (Annelida, Terebellidae sensu lato) from the French coasts
Cette thĂšse a pour objectif de rĂ©viser la taxonomie des espĂšces françaises dâannĂ©lides polychĂštes appartenant aux cinq familles des Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae sensu stricto, Thelepodidae et Trichobranchidae). Ces vers spaghetti sont caractĂ©risĂ©s par la prĂ©sence de nombreux tentacules buccaux non rĂ©tractables servant Ă leur nutrition et leur assurant un rĂ©gime dĂ©posivore.Les individus Ă©tudiĂ©s dans le cadre de cette thĂšse ont Ă©tĂ© prĂ©levĂ©s lors de diffĂ©rents projets de recherche et dâobservation menĂ©s par les Ă©quipes hĂ©bergĂ©es dans les stations marines françaises, mais Ă©galement lors dâĂ©chantillonnages spĂ©cifiques. Des matĂ©riels types, archivĂ©s au Museum National dâHistoire Naturelle, ont Ă©galement Ă©tĂ© empruntĂ©s. Cette Ă©tude est au centre du « Spaghetti Project », projet collaboratif impliquant les taxonomistes benthiques des diffĂ©rentes stations marines françaises (RESOMAR, RESeau des Stations et Observatoires MARins).Les eaux cĂŽtiĂšres françaises sont des zones Ă©tudiĂ©es depuis plusieurs siĂšcles par les premiers taxinomistes et les Ă©cologistes benthiques. Cependant, lâĂ©tude de nombreux spĂ©cimens de vers spaghetti Ă lâaide de nouveaux outils, comme la microscopie Ă©lectronique Ă balayage ou lâanalyses molĂ©culaire, a rĂ©vĂ©lĂ© lâexistence de 31 espĂšces nouvelles pour la science.Ces espĂšces ont probablement « toujours » Ă©tĂ© prĂ©sentes le long des cĂŽtes mais mal identifiĂ©es pendant des dĂ©cennies. Plusieurs raisons peuvent expliquer ces lacunes. La premiĂšre est que ces vers sont extrĂȘmement complexes Ă identifier car les caractĂšres morphologiques nĂ©cessitent des observations pointues et des outils modernes. DeuxiĂšmement, la plupart des espĂšces europĂ©ennes ont Ă©tĂ© dĂ©crites aux 18Ăšme et 19Ăšme siĂšcles. Les standards taxonomiques de lâĂ©poque Ă©taient trĂšs diffĂ©rents, avec des descriptions trĂšs brĂšves et des illustrations (quand elles Ă©taient prĂ©sentes) de qualitĂ© mĂ©diocre. De plus, les matĂ©riels types Ă©taient rarement dĂ©posĂ©s dans une collection dâun musĂ©um, et quand ils lâĂ©taient ont malheureusement souvent Ă©tĂ© endommagĂ©s ou perdus, empĂȘchant des comparaisons avec des spĂ©cimens nouvellement collectĂ©s. Enfin, il y a eu jusque dans les annĂ©es 1980, une idĂ©e largement rĂ©pandue selon laquelle les espĂšces de polychĂštes Ă large distribution Ă©taient trĂšs communes. LâĂ©tude de ces espĂšces soi-disant cosmopolites a rĂ©vĂ©lĂ© lâexistence de nombreuses espĂšces cryptiques dans le monde entier en gĂ©nĂ©ral, et en France en particulier.The objective of this thesis is to revise the taxonomy of the French species of polychaetes belonging to the five families of Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae, Thelepodidae and Trichobranchidae). These spaghetti worms are characterised by the presence of multiple non-retractable buccal tentacles used for feeding (deposit feeders).The specimens studied in this thesis were collected during different research and observation programs or specific samplings carried out by scientists in the different French laboratories. Type materials from the Museum National dâHistoire Naturelle were also loaned.This study is at the heart of the âSpaghetti Projectâ, project involving benthic taxonomists from French marine stations (RESOMAR network).French coastal waters are well-known areas, studied for several centuries by early taxonomists and benthic ecologists. However, studying numerous spaghetti worms with new tools, like scanning electron microscope and molecular analysis, has revealed the existence of 31 species new for science.These species have probably âalwaysâ been present along the French coasts but misidentified for decades. Several reasons can explain this situation. First, these worms are relatively challenging to identify because of diagnostic characters requiring detailed examination and modern tools. Secondly, most of the European species were described in the 18 and 19th centuries. Taxonomic standards at that time were very different with very brief descriptions and illustrations (when present) of poor quality. Moreover, type material was rarely deposited in a museum collection, and when deposited subsequently often lost or damaged, preventing any comparison with specimens newly collected. Finally, until 1980s, there was a wide perception that widespread species were very common among polychaetes. Studying these so-called âcosmopolitanâ species in detail reveals the existence of numerous cryptic species in different parts of the world, in France in particular
Revision of spaghetti worms (Annelida, Terebellidae sensu lato) from the French coasts
Cette thĂšse a pour objectif de rĂ©viser la taxonomie des espĂšces françaises dâannĂ©lides polychĂštes appartenant aux cinq familles des Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae sensu stricto, Thelepodidae et Trichobranchidae). Ces vers spaghetti sont caractĂ©risĂ©s par la prĂ©sence de nombreux tentacules buccaux non rĂ©tractables servant Ă leur nutrition et leur assurant un rĂ©gime dĂ©posivore.Les individus Ă©tudiĂ©s dans le cadre de cette thĂšse ont Ă©tĂ© prĂ©levĂ©s lors de diffĂ©rents projets de recherche et dâobservation menĂ©s par les Ă©quipes hĂ©bergĂ©es dans les stations marines françaises, mais Ă©galement lors dâĂ©chantillonnages spĂ©cifiques. Des matĂ©riels types, archivĂ©s au Museum National dâHistoire Naturelle, ont Ă©galement Ă©tĂ© empruntĂ©s. Cette Ă©tude est au centre du « Spaghetti Project », projet collaboratif impliquant les taxonomistes benthiques des diffĂ©rentes stations marines françaises (RESOMAR, RESeau des Stations et Observatoires MARins).Les eaux cĂŽtiĂšres françaises sont des zones Ă©tudiĂ©es depuis plusieurs siĂšcles par les premiers taxinomistes et les Ă©cologistes benthiques. Cependant, lâĂ©tude de nombreux spĂ©cimens de vers spaghetti Ă lâaide de nouveaux outils, comme la microscopie Ă©lectronique Ă balayage ou lâanalyses molĂ©culaire, a rĂ©vĂ©lĂ© lâexistence de 31 espĂšces nouvelles pour la science.Ces espĂšces ont probablement « toujours » Ă©tĂ© prĂ©sentes le long des cĂŽtes mais mal identifiĂ©es pendant des dĂ©cennies. Plusieurs raisons peuvent expliquer ces lacunes. La premiĂšre est que ces vers sont extrĂȘmement complexes Ă identifier car les caractĂšres morphologiques nĂ©cessitent des observations pointues et des outils modernes. DeuxiĂšmement, la plupart des espĂšces europĂ©ennes ont Ă©tĂ© dĂ©crites aux 18Ăšme et 19Ăšme siĂšcles. Les standards taxonomiques de lâĂ©poque Ă©taient trĂšs diffĂ©rents, avec des descriptions trĂšs brĂšves et des illustrations (quand elles Ă©taient prĂ©sentes) de qualitĂ© mĂ©diocre. De plus, les matĂ©riels types Ă©taient rarement dĂ©posĂ©s dans une collection dâun musĂ©um, et quand ils lâĂ©taient ont malheureusement souvent Ă©tĂ© endommagĂ©s ou perdus, empĂȘchant des comparaisons avec des spĂ©cimens nouvellement collectĂ©s. Enfin, il y a eu jusque dans les annĂ©es 1980, une idĂ©e largement rĂ©pandue selon laquelle les espĂšces de polychĂštes Ă large distribution Ă©taient trĂšs communes. LâĂ©tude de ces espĂšces soi-disant cosmopolites a rĂ©vĂ©lĂ© lâexistence de nombreuses espĂšces cryptiques dans le monde entier en gĂ©nĂ©ral, et en France en particulier.The objective of this thesis is to revise the taxonomy of the French species of polychaetes belonging to the five families of Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae, Thelepodidae and Trichobranchidae). These spaghetti worms are characterised by the presence of multiple non-retractable buccal tentacles used for feeding (deposit feeders).The specimens studied in this thesis were collected during different research and observation programs or specific samplings carried out by scientists in the different French laboratories. Type materials from the Museum National dâHistoire Naturelle were also loaned.This study is at the heart of the âSpaghetti Projectâ, project involving benthic taxonomists from French marine stations (RESOMAR network).French coastal waters are well-known areas, studied for several centuries by early taxonomists and benthic ecologists. However, studying numerous spaghetti worms with new tools, like scanning electron microscope and molecular analysis, has revealed the existence of 31 species new for science.These species have probably âalwaysâ been present along the French coasts but misidentified for decades. Several reasons can explain this situation. First, these worms are relatively challenging to identify because of diagnostic characters requiring detailed examination and modern tools. Secondly, most of the European species were described in the 18 and 19th centuries. Taxonomic standards at that time were very different with very brief descriptions and illustrations (when present) of poor quality. Moreover, type material was rarely deposited in a museum collection, and when deposited subsequently often lost or damaged, preventing any comparison with specimens newly collected. Finally, until 1980s, there was a wide perception that widespread species were very common among polychaetes. Studying these so-called âcosmopolitanâ species in detail reveals the existence of numerous cryptic species in different parts of the world, in France in particular
Révision des vers spaghetti (Annélides, Terebellidae sensu lato) des cÎtes françaises
The objective of this thesis is to revise the taxonomy of the French species of polychaetes belonging to the five families of Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae, Thelepodidae and Trichobranchidae). These spaghetti worms are characterised by the presence of multiple non-retractable buccal tentacles used for feeding (deposit feeders).The specimens studied in this thesis were collected during different research and observation programs or specific samplings carried out by scientists in the different French laboratories. Type materials from the Museum National dâHistoire Naturelle were also loaned.This study is at the heart of the âSpaghetti Projectâ, project involving benthic taxonomists from French marine stations (RESOMAR network).French coastal waters are well-known areas, studied for several centuries by early taxonomists and benthic ecologists. However, studying numerous spaghetti worms with new tools, like scanning electron microscope and molecular analysis, has revealed the existence of 31 species new for science.These species have probably âalwaysâ been present along the French coasts but misidentified for decades. Several reasons can explain this situation. First, these worms are relatively challenging to identify because of diagnostic characters requiring detailed examination and modern tools. Secondly, most of the European species were described in the 18 and 19th centuries. Taxonomic standards at that time were very different with very brief descriptions and illustrations (when present) of poor quality. Moreover, type material was rarely deposited in a museum collection, and when deposited subsequently often lost or damaged, preventing any comparison with specimens newly collected. Finally, until 1980s, there was a wide perception that widespread species were very common among polychaetes. Studying these so-called âcosmopolitanâ species in detail reveals the existence of numerous cryptic species in different parts of the world, in France in particular.Cette thĂšse a pour objectif de rĂ©viser la taxonomie des espĂšces françaises dâannĂ©lides polychĂštes appartenant aux cinq familles des Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae sensu stricto, Thelepodidae et Trichobranchidae). Ces vers spaghetti sont caractĂ©risĂ©s par la prĂ©sence de nombreux tentacules buccaux non rĂ©tractables servant Ă leur nutrition et leur assurant un rĂ©gime dĂ©posivore.Les individus Ă©tudiĂ©s dans le cadre de cette thĂšse ont Ă©tĂ© prĂ©levĂ©s lors de diffĂ©rents projets de recherche et dâobservation menĂ©s par les Ă©quipes hĂ©bergĂ©es dans les stations marines françaises, mais Ă©galement lors dâĂ©chantillonnages spĂ©cifiques. Des matĂ©riels types, archivĂ©s au Museum National dâHistoire Naturelle, ont Ă©galement Ă©tĂ© empruntĂ©s. Cette Ă©tude est au centre du « Spaghetti Project », projet collaboratif impliquant les taxonomistes benthiques des diffĂ©rentes stations marines françaises (RESOMAR, RESeau des Stations et Observatoires MARins).Les eaux cĂŽtiĂšres françaises sont des zones Ă©tudiĂ©es depuis plusieurs siĂšcles par les premiers taxinomistes et les Ă©cologistes benthiques. Cependant, lâĂ©tude de nombreux spĂ©cimens de vers spaghetti Ă lâaide de nouveaux outils, comme la microscopie Ă©lectronique Ă balayage ou lâanalyses molĂ©culaire, a rĂ©vĂ©lĂ© lâexistence de 31 espĂšces nouvelles pour la science.Ces espĂšces ont probablement « toujours » Ă©tĂ© prĂ©sentes le long des cĂŽtes mais mal identifiĂ©es pendant des dĂ©cennies. Plusieurs raisons peuvent expliquer ces lacunes. La premiĂšre est que ces vers sont extrĂȘmement complexes Ă identifier car les caractĂšres morphologiques nĂ©cessitent des observations pointues et des outils modernes. DeuxiĂšmement, la plupart des espĂšces europĂ©ennes ont Ă©tĂ© dĂ©crites aux 18Ăšme et 19Ăšme siĂšcles. Les standards taxonomiques de lâĂ©poque Ă©taient trĂšs diffĂ©rents, avec des descriptions trĂšs brĂšves et des illustrations (quand elles Ă©taient prĂ©sentes) de qualitĂ© mĂ©diocre. De plus, les matĂ©riels types Ă©taient rarement dĂ©posĂ©s dans une collection dâun musĂ©um, et quand ils lâĂ©taient ont malheureusement souvent Ă©tĂ© endommagĂ©s ou perdus, empĂȘchant des comparaisons avec des spĂ©cimens nouvellement collectĂ©s. Enfin, il y a eu jusque dans les annĂ©es 1980, une idĂ©e largement rĂ©pandue selon laquelle les espĂšces de polychĂštes Ă large distribution Ă©taient trĂšs communes. LâĂ©tude de ces espĂšces soi-disant cosmopolites a rĂ©vĂ©lĂ© lâexistence de nombreuses espĂšces cryptiques dans le monde entier en gĂ©nĂ©ral, et en France en particulier
Révision des vers spaghetti (Annélides, Terebellidae sensu lato) des cÎtes françaises
The objective of this thesis is to revise the taxonomy of the French species of polychaetes belonging to the five families of Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae, Thelepodidae and Trichobranchidae). These spaghetti worms are characterised by the presence of multiple non-retractable buccal tentacles used for feeding (deposit feeders).The specimens studied in this thesis were collected during different research and observation programs or specific samplings carried out by scientists in the different French laboratories. Type materials from the Museum National dâHistoire Naturelle were also loaned.This study is at the heart of the âSpaghetti Projectâ, project involving benthic taxonomists from French marine stations (RESOMAR network).French coastal waters are well-known areas, studied for several centuries by early taxonomists and benthic ecologists. However, studying numerous spaghetti worms with new tools, like scanning electron microscope and molecular analysis, has revealed the existence of 31 species new for science.These species have probably âalwaysâ been present along the French coasts but misidentified for decades. Several reasons can explain this situation. First, these worms are relatively challenging to identify because of diagnostic characters requiring detailed examination and modern tools. Secondly, most of the European species were described in the 18 and 19th centuries. Taxonomic standards at that time were very different with very brief descriptions and illustrations (when present) of poor quality. Moreover, type material was rarely deposited in a museum collection, and when deposited subsequently often lost or damaged, preventing any comparison with specimens newly collected. Finally, until 1980s, there was a wide perception that widespread species were very common among polychaetes. Studying these so-called âcosmopolitanâ species in detail reveals the existence of numerous cryptic species in different parts of the world, in France in particular.Cette thĂšse a pour objectif de rĂ©viser la taxonomie des espĂšces françaises dâannĂ©lides polychĂštes appartenant aux cinq familles des Terebellidae sensu lato (Polycirridae, Telothelepodidae, Terebellidae sensu stricto, Thelepodidae et Trichobranchidae). Ces vers spaghetti sont caractĂ©risĂ©s par la prĂ©sence de nombreux tentacules buccaux non rĂ©tractables servant Ă leur nutrition et leur assurant un rĂ©gime dĂ©posivore.Les individus Ă©tudiĂ©s dans le cadre de cette thĂšse ont Ă©tĂ© prĂ©levĂ©s lors de diffĂ©rents projets de recherche et dâobservation menĂ©s par les Ă©quipes hĂ©bergĂ©es dans les stations marines françaises, mais Ă©galement lors dâĂ©chantillonnages spĂ©cifiques. Des matĂ©riels types, archivĂ©s au Museum National dâHistoire Naturelle, ont Ă©galement Ă©tĂ© empruntĂ©s. Cette Ă©tude est au centre du « Spaghetti Project », projet collaboratif impliquant les taxonomistes benthiques des diffĂ©rentes stations marines françaises (RESOMAR, RESeau des Stations et Observatoires MARins).Les eaux cĂŽtiĂšres françaises sont des zones Ă©tudiĂ©es depuis plusieurs siĂšcles par les premiers taxinomistes et les Ă©cologistes benthiques. Cependant, lâĂ©tude de nombreux spĂ©cimens de vers spaghetti Ă lâaide de nouveaux outils, comme la microscopie Ă©lectronique Ă balayage ou lâanalyses molĂ©culaire, a rĂ©vĂ©lĂ© lâexistence de 31 espĂšces nouvelles pour la science.Ces espĂšces ont probablement « toujours » Ă©tĂ© prĂ©sentes le long des cĂŽtes mais mal identifiĂ©es pendant des dĂ©cennies. Plusieurs raisons peuvent expliquer ces lacunes. La premiĂšre est que ces vers sont extrĂȘmement complexes Ă identifier car les caractĂšres morphologiques nĂ©cessitent des observations pointues et des outils modernes. DeuxiĂšmement, la plupart des espĂšces europĂ©ennes ont Ă©tĂ© dĂ©crites aux 18Ăšme et 19Ăšme siĂšcles. Les standards taxonomiques de lâĂ©poque Ă©taient trĂšs diffĂ©rents, avec des descriptions trĂšs brĂšves et des illustrations (quand elles Ă©taient prĂ©sentes) de qualitĂ© mĂ©diocre. De plus, les matĂ©riels types Ă©taient rarement dĂ©posĂ©s dans une collection dâun musĂ©um, et quand ils lâĂ©taient ont malheureusement souvent Ă©tĂ© endommagĂ©s ou perdus, empĂȘchant des comparaisons avec des spĂ©cimens nouvellement collectĂ©s. Enfin, il y a eu jusque dans les annĂ©es 1980, une idĂ©e largement rĂ©pandue selon laquelle les espĂšces de polychĂštes Ă large distribution Ă©taient trĂšs communes. LâĂ©tude de ces espĂšces soi-disant cosmopolites a rĂ©vĂ©lĂ© lâexistence de nombreuses espĂšces cryptiques dans le monde entier en gĂ©nĂ©ral, et en France en particulier
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