Benchmarking global biodiversity of decapod crustaceans (Crustacea: Decapoda)

A new assessment of the global biodiversity of decapod Crustacea (to 31 December 2022) records 17,229 species in 2,550 genera and 203 families. These figures are derived from a well-curated dataset maintained on the online platform DecaNet, a subsidiary of the World Register of Marine Species (WoRMS). Distinct phases are recognised in the discovery process (as measured by species descriptions) corresponding to major historical and geopolitical time periods, with the current rate of species descriptions being more than three times higher than in the Victorian age of global exploration. Future trends are briefly explored, and it is recognised that a large number of species remain to be discovered and described

Diadromie, dispersion et histoire évolutive des complexes "Caridina nilotica" et "Caridina weberi" (Crustacea - Decapoda - Atyidae) dans les systèmes insulaires de l’Indo-Pacifique

Rivers of tropical islands harbor organisms that have developped a diadromous lifecycle, shared between a freshwater adult phase and a marine larval phase: amphidromy. Among these organisms, in the Indo-Pacific area are found shrimps of the genus Caridina H. Milne Edwards, 1837. With more than 300 described species it is the most speciose genus of the infra-order Caridea, with a most confused and complicated taxonomy. Within this genus, two species complexes are particularly well-represented in insular systems of the Indo-Pacific, the C. nilotica complex and the C. weberi complex. Thanks to the development of new sequencing techniques, new methods of integrative taxonomy appeared, allowing to resolve part of the taxonomic complexity of these taxa. The aim of the thesis was to apply an integrative taxonomy approach to species belonging to C. nilotica and C. weberi complexes in order to clarify their taxonomy and have a better understanding of their biology and provide tools to managers for establishing a better conservation of these species and their environments. After showing that some morphological characters traditionally used to describe species were influenced by the environment and so, highly variable, the integrative taxonomy was led on 92 species, allowing to obtain 1,682 sequences to which are added 32 complete and 97 partial mitochondrial genomes, highlighting 43 new species, some of them described during the thesis. Phylogenetic relationships among the species of the two complexes were reconstructed from a large molecular dataset, allowing to show that the complexes are monophyletic groups, with habitat differences. Finally, the feasibility of a sclerochronological study of amphidromy in a species of the C. weberi complex (C. multidentata) was tested on the eyestalk cuticle, with a study of the ultrastructure of the cuticle, described for the first time in this species.Les cours d’eau des îles tropicales abritent des organismes qui ont développé un cycle de vie diadrome, partagé entre une phase adulte en eau douce et une phase larvaire marine : l’amphidromie. Parmi ces organismes, dans la zone Indo-Pacifique, on trouve les crevettes du genre Caridina H. Milne Edwards, 1837. Avec plus de 300 espèces décrites, il s’agit du genre le plus diversifié de l’infra-ordre des Caridea, avec une systématique extrêmement confuse et compliquée. Au sein de ce genre, deux complexes d’espèces sont particulièrement bien représentés dans les systèmes insulaires de l’Indo-Pacifique, le complexe Caridina nilotica et le complexe C. weberi. Grâce au développement de nouvelles techniques de séquençage de nouvelles méthodes de taxonomie dite intégrative sont apparues, permettant de résoudre une partie des problèmes taxonomiques de ces groupes. L’objectif de la thèse était d’appliquer une approche de taxonomie intégrative aux espèces des complexes C. nilotica et C. weberi afin de clarifier leur systématique et, de fait, mieux appréhender leur biologie et fournir les outils aux gestionnaires pour mettre en place une meilleure conservation de ces espèces et de leurs milieux. Après avoir montré que certains caractères morphologiques traditionnellement utilisés pour décrire les espèces étaient influencés par l’environnement et donc fortement variables, l’étude de taxonomie intégrative a été conduite sur 92 espèces, permettant d’obtenir 1682 séquences auxquelles s’ajoutent 32 génomes mitochondriaux complets et 97 partiels, mettant en évidence 43 espèces nouvelles, certaines décrites au cours de la thèse. Les relations phylogénétiques entre les espèces des deux complexes ont été reconstruites à partir d’un grand jeu de données moléculaires, permettant de montrer que les complexes sont des groupes monophylétiques avec des différences en terme d’habitats occupés. Enfin, la faisabilité de l’étude sclérochronologique de l’amphidromie chez une espèce du complexe C. weberi (C. multidentata) a été testée sur la cuticule du pédoncule oculaire, avec une étude de l’ultrastructure de la cuticule, décrite pour la première fois chez cette espèce

Diadromy, dispersion and evolutive history of the species complexes Caridina nilotica and Caridina weberi (Crustacea - Decapoda - Atyidae) in insular systems of the Indo-Pacific

Les cours d’eau des îles tropicales abritent des organismes qui ont développé un cycle de vie diadrome, partagé entre une phase adulte en eau douce et une phase larvaire marine : l’amphidromie. Parmi ces organismes, dans la zone Indo-Pacifique, on trouve les crevettes du genre Caridina H. Milne Edwards, 1837. Avec plus de 300 espèces décrites, il s’agit du genre le plus diversifié de l’infra-ordre des Caridea, avec une systématique extrêmement confuse et compliquée. Au sein de ce genre, deux complexes d’espèces sont particulièrement bien représentés dans les systèmes insulaires de l’Indo-Pacifique, le complexe Caridina nilotica et le complexe C. weberi. Grâce au développement de nouvelles techniques de séquençage de nouvelles méthodes de taxonomie dite intégrative sont apparues, permettant de résoudre une partie des problèmes taxonomiques de ces groupes. L’objectif de la thèse était d’appliquer une approche de taxonomie intégrative aux espèces des complexes C. nilotica et C. weberi afin de clarifier leur systématique et, de fait, mieux appréhender leur biologie et fournir les outils aux gestionnaires pour mettre en place une meilleure conservation de ces espèces et de leurs milieux. Après avoir montré que certains caractères morphologiques traditionnellement utilisés pour décrire les espèces étaient influencés par l’environnement et donc fortement variables, l’étude de taxonomie intégrative a été conduite sur 92 espèces, permettant d’obtenir 1682 séquences auxquelles s’ajoutent 32 génomes mitochondriaux complets et 97 partiels, mettant en évidence 43 espèces nouvelles, certaines décrites au cours de la thèse. Les relations phylogénétiques entre les espèces des deux complexes ont été reconstruites à partir d’un grand jeu de données moléculaires, permettant de montrer que les complexes sont des groupes monophylétiques avec des différences en terme d’habitats occupés. Enfin, la faisabilité de l’étude sclérochronologique de l’amphidromie chez une espèce du complexe C. weberi (C. multidentata) a été testée sur la cuticule du pédoncule oculaire, avec une étude de l’ultrastructure de la cuticule, décrite pour la première fois chez cette espèce.Rivers of tropical islands harbor organisms that have developped a diadromous lifecycle, shared between a freshwater adult phase and a marine larval phase: amphidromy. Among these organisms, in the Indo-Pacific area are found shrimps of the genus Caridina H. Milne Edwards, 1837. With more than 300 described species it is the most speciose genus of the infra-order Caridea, with a most confused and complicated taxonomy. Within this genus, two species complexes are particularly well-represented in insular systems of the Indo-Pacific, the C. nilotica complex and the C. weberi complex. Thanks to the development of new sequencing techniques, new methods of integrative taxonomy appeared, allowing to resolve part of the taxonomic complexity of these taxa. The aim of the thesis was to apply an integrative taxonomy approach to species belonging to C. nilotica and C. weberi complexes in order to clarify their taxonomy and have a better understanding of their biology and provide tools to managers for establishing a better conservation of these species and their environments. After showing that some morphological characters traditionally used to describe species were influenced by the environment and so, highly variable, the integrative taxonomy was led on 92 species, allowing to obtain 1,682 sequences to which are added 32 complete and 97 partial mitochondrial genomes, highlighting 43 new species, some of them described during the thesis. Phylogenetic relationships among the species of the two complexes were reconstructed from a large molecular dataset, allowing to show that the complexes are monophyletic groups, with habitat differences. Finally, the feasibility of a sclerochronological study of amphidromy in a species of the C. weberi complex (C. multidentata) was tested on the eyestalk cuticle, with a study of the ultrastructure of the cuticle, described for the first time in this species

A new freshwater crab of the family Hymenosomatidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and an updated review of the hymenosomatid fauna of New Caledonia

International audienceA new genus and species, Richerius marqueti gen. et sp. nov., of a crab of the family Hymenosomatidae MacLeay, 1838 are described from the inland waters of New Caledonia based on several specimens collected in two streams at altitudes of 180 m and 500 m, respectively. Richerius marqueti gen. et sp. nov. was compared to the other freshwater species known in New Caledonia, Odiomaris pilosus (A. Milne-Edwards, 1873), and to species of Amarinus Lucas, 1980, a genus comprising many freshwater species in New zealand, Australia, Indonesia, the Philippines, and Papua New Guinea, but never recorded in New Caledonia. The barcode fragment of the COI mitochondrial gene was sequenced for seven specimens of R. marqueti gen. et sp. nov., and all sequences were deposited in GenBank. A brief and updated review of the New Caledonian marine and freshwater hymenosmatid fauna is provided

A new freshwater crab of the family Hymenosomatidae MacLeay, 1838 from New Caledonia (Crustacea, Decapoda, Brachyura) and an updated review of the hymenosomatid fauna of New Caledonia

A new genus and species, Richerius marqueti gen. et sp. nov., of a crab of the family Hymenosomatidae MacLeay, 1838 are described from the inland waters of New Caledonia based on several specimens collected in two streams at altitudes of 180 m and 500 m, respectively. Richerius marqueti gen. et sp. nov. was compared to the other freshwater species known in New Caledonia, Odiomaris pilosus (A. Milne-Edwards, 1873), and to species of Amarinus Lucas, 1980, a genus comprising many freshwater species in New Zealand, Australia, Indonesia, the Philippines, and Papua New Guinea, but never recorded in New Caledonia. The barcode fragment of the COI mitochondrial gene was sequenced for seven specimens of R. marqueti gen. et sp. nov., and all sequences were deposited in GenBank. A brief and updated review of the New Caledonian marine and freshwater hymenosmatid fauna is provided.</p

Figure 5. Caridina tupaia n in Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography

Figure 5. Caridina tupaia n. sp. Holotype (MNHN-IU-2018-260; DNA: CA2058), (a). first pereiopod; (b). second pereiopod; (c). third pereiopod; (d). fifth pereiopod; e. dactylus of fifth pereiopod; (f). dactylus of third pereiopod; (g). cephalothorax; h. preanal carina; (j). uropodal diaeresis; (k). telson. Paratype (MNHN-IU-2018-268), (i). eggs. Paratype (MNHN-IU-2018-261; DNA: CA1048), (l). first pleopod; m. second pleopod.Published as part of Mazancourt, Valentin de, Marquet, Gérard & Keith, Philippe, 2019, Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography, pp. 815-847 in Journal of Natural History 53 (13) on page 829, DOI: 10.1080/00222933.2019.1612959, http://zenodo.org/record/367564

Author Correction: Exceptional preservation of internal organs in a new fossil species of freshwater shrimp (Caridea: Palaemonoidea) from the Eocene of Messel (Germany)

International audiencede Mazancourt et al. (2022) described a new species of fossil freshwater shrimp, Bechleja brevirostris from the Eocene of Messel (Germany). Although the species is fully characterized and figured in the original description, it was published in an online-only journal issue and the article does not include evidence of registration in ZooBank within the work itself, which is a requirement by Article 8.5.3 of the International Code of Zoological Nomenclature 1. Therefore, the newly proposed species-group name Bechleja brevirostris is not available

Caridina weberi De Man 1892

Key of the Polynesian species of the C. weberi complexPublished as part of Mazancourt, Valentin de, Marquet, Gérard & Keith, Philippe, 2019, Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography, pp. 815-847 in Journal of Natural History 53 (13) on page 838, DOI: 10.1080/00222933.2019.1612959, http://zenodo.org/record/367564

Caridina futunensis Mazancourt & Marquet & Keith 2019, n. sp.

Caridina futunensisn. sp. (Figure 3) Caridina weberi – Keith and Marquet 2011: 42 – 43; Mary et al. 2006: 33. Material examined Type material. Holotype: 1 &female; ovig, cl 2.8 mm, 14 October 2004, 14°17.278 ′ S 178° 09.037 ʹ W, Leava river, Futuna, altitude 97m, G. Marquet, P. Keith & N. Mary coll., MNHN- IU-2018 – 195 (DNA: CA2118). Paratypes: 1 &female; ovig, cl 2.6 mm, same data as for holotype, MNHN-IU-2018 – 208 (DNA: CA2119); 1 &female; ovig, cl 2.9 mm, same data as for holotype, MNHN-IU -2018 – 209 (DNA: CA2116); 1 &female; ovig, cl 3.1 mm, same data as for holotype, MNHN- IU-2017 – 1460 (DNA: CA2032); 1 &female; ovig, 3.1 mm, same data as for holotype, MNHN-IU - 2017 – 64 (DNA: CA2117); 1 &female;, cl 3.0 mm, same data as for holotype, MNHN-IU -2017 – 1459 (DNA: CA2031); 1 &female;, cl 3.6 mm, 12 October 2004, 14°17.738 ′ S 178° 08.423 ʹ W, Vainifao river, Futuna, altitude 150m, G. Marquet, P. Keith & N. Mary coll., MNHN-IU- 2017 – 65 (DNA: CA2033). Comparative material. Type material Caridina parvirostris De Man, 1892. Syntypes: 2 &female;, cl. 3.1 – 3.2 mm, river near Bombang, Flores Island, Indonesia, M. Weber coll., MNHN-IU-2015-1748; 1 &female;, cl. 4.2 mm, same data as for previous, MNHN-IU-2015- 1754. Caridina weberi, 1892. Syntypes: 2 &male;, cl 4.4 – 4.5 mm and 1 &female; ovig, cl 6.1 mm, Kotting, Flores Island, Indonesia, M. Weber coll., MNHN-IU-2015 – 1755. Description Cephalothorax. Rostrum (Figures 3 (h) and 7(F)): always bent down, short, 0.2 – 0.3 of cl, reaching to base of first segment of antennular peduncle, armed dorsally with 5 – 10 teeth, 0 of them on carapace posterior to orbital margin, ventral margin with 0 – 3 teeth. Rostrum formula (0) 5 – 10/0 – 3. Suborbital angle indistinguishably fused with antennal spine. Pterygostomian margin rectangularly rounded. Eyes well developed, anterior end reaching to 0.73 length of antennular peduncle basal segment. Antennular peduncle 0.47 times as long as carapace. Anterolateral angle reaching 0.20 length of second segment, second segment subequal to third. Stylocerite reaching to 0.90 length of antennular peduncle basal segment. Scaphocerite distincly overreaching tip of antennular peduncle, about 2.1 times longer than wide. Mouthparts. Left mandible, right mandible, first maxilla, second maxilla, first maxilliped, second maxilliped and third maxilliped typical of genus. Pereiopods. Epipods on first four pereiopods. Pereiopod 1 (Figure 3 (a)): chela about 1.9 – 2.2 times as long as wide, movable finger 2.3 – 2.9 times as long as wide, 0.7 – 1.0 times length of palm, carpus 1.3 – 1.5 times as long as wide. Pereiopod 2 (Figure 3 (b)) More slender and longer than first pereiopod with chela 2.4 – 2.6 times as long as wide: movable finger 4.0 – 5.0 times as long as wide, 1.5 – 1.9 times length of palm, carpus slender 5.5 – 6.2 times as long as wide. Pereiopod 3 (Figure 3 (c, e)): stout, dactylus 2.6 – 3.9 times as long as wide (terminal spine included) with 5 spines on flexor margin including terminal spine, propodus 8.8 – 13.1 times as long as wide, 3.7 – 4.5 times as long as dactylus. Pereiopod 5 (Figure 3 (d, f)): dactylus 2.9 – 3.7 as long as wide with 25 – 38 spiniform setae on flexor margin, propodus 12.2 – 13.8 times as long as wide, 4.3 – 4.9 times as long as dactylus. Abdomen. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite about 0.5 of carapace length, 1.3 times as long as fifth somite, shorter than telson. Telson (Figure 3 (k)) 2 times as long as wide, with four to six pairs of dorsal spinules and one pair of dorsolateral spinules, posterior margin with median process, rounded with five intermediate plumose setae longer than lateral spines. First male pleopod: Unknown (no males in the collections). Second male pleopod: Unknown (no males in the collections). Preanal carina (Figure 3 (g)): High, unarmed. Uropodal diaeresis (Figure 3 (j)) with 17 – 22 spinules. Eggs (Figure 3 (i)): Size 0.43 – 0.53 × 0.25 – 0.30mm. Habitat (Figure 7 (g)) This new species prefers fresh and well-oxygenated running waters from the lower course to the higher course. Etymology This new species is named futunensis, from the name of the island, Futuna, where this new species occurs. Colour pattern Unknown Distribution (Figure 8) This species is known only from Futuna so far and seems to be endemic. Remarks This species looks like C. parvirostris by its bent rostrum with 5 – 10 dorsal teeth and no postorbital teeth (vs bent rostrum with 8 – 10 dorsal teeth and no postorbital teeth in C. parvirostris) but the P2 carpus is shorter 5.5 – 6.2 times as long as wide (vs 6.0 – 7.4 in C. parvirostris) and so is P2 chela 2.4 – 2.6 times as long as wide (vs 2.6 – 3.0 in C. parvirostris). This species differs from C. marquesensis n. sp. and C. tupaia n. sp. by its shorter rostrum 0.2 – 0.3 of cl (vs 0.3 – 0.4 in C. marquesensis n. sp. and C. tupaia n. sp.), fewer dorsal teeth on the rostrum 5 – 10 (vs 10 – 13 in C. marquesensis n. sp. and 8 – 14 in C. tupaia n. sp.) and P5 dactylus with fewer spiniform setae on flexor margin 25 – 38 spines (vs 32 – 55 in C. marquesensis n. sp. and 29 – 54 in C. tupaia n. sp.) and by its telson with five intermediate setae longer than lateral spines (vs 6 – 14 in C. marquesensis n. sp. and 6 – 10 in C. tupaia n. sp.). This species differs from C. rapaensis by its bent rostrum with more dorsal teeth (5 – 10) (vs bent rostrum with 0 – 5 in C. rapaensis) and its P5 dactylus ending in two large claws (vs one large claw in C. rapaensis).Published as part of Mazancourt, Valentin de, Marquet, Gérard & Keith, Philippe, 2019, Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography, pp. 815-847 in Journal of Natural History 53 (13) on pages 822-825, DOI: 10.1080/00222933.2019.1612959, http://zenodo.org/record/367564

First Occurrence of the Genus Australatya (Crustacea: Decapoda: Atyidae) in Melanesia and Polynesia with Description of a New Species

International audienceDuring specific inventories led by the Muséum national d'Histoire naturelle (MNHN, Paris), numerous specimens of Atyidae, particulary of Atya-like shrimps were collected in Melanesia (Vanuatu, Solomon Islands) and in Polynesia (Futuna, Samoa). These specimens were morphologically and genetically examined. Our study revealed that some specimens belonged to a new species in the genus AustralatyaChace, 1983. The aim of this paper is to describe this new species, Australatya keithi sp. nov., and discuss the distribution of its genus in the studied area