Adiponectin promotes syncytialisation of BeWo cell line and primary trophoblast cells

<p>Abstract</p> <p>Background</p> <p>In human pregnancy, a correct placentation depends on trophoblast proliferation, differentiation, migration and invasion. These processes are highly regulated by placental hormones, growth factors and cytokines. Recently, we have shown that adiponectin, an adipokine, has anti-proliferative effects on trophoblastic cells. Here, we complete this study by demonstrating that adiponectin modulates BeWo and human villous cytotrophoblast cell differentiation.</p> <p>Results</p> <p>We showed that hCG secretion was up-regulated by adiponectin treatment in both BeWo cells and human cytotrophoblasts from very early placentas (5-6 weeks). The expression of two trophoblast differentiation markers, leptin and syncytin 2, was also up-regulated by adiponectin in BeWo cells. Moreover, adiponectin treatment induced a loss of E-cadherin staining in these cells. In parallel, we demonstrated that AdipoR1 and AdipoR2 are up-regulated during forskolin induced BeWo cell differentiation, reinforcing the role of adiponectin in trophoblast syncytialization. SiRNA mediated down-regulation of AdipoR1 and AdipoR2 was used to demonstrate that adiponectin effects on differentiation were essentially mediated by these receptors. Finally, using a specific inhibitor, we demonstrated that the PKA signalling pathway could be one pathway involved in adiponectin effects on trophoblast differentiation.</p> <p>Conclusion</p> <p>Adiponectin enhances the differentiation process of trophoblast cells and could thus be involved in functional syncytiotrophoblast formation.</p

Mild forms of hypophosphatasia mostly result from dominant negative effect of severe alleles or from compound heterozygosity for severe and moderate alleles

<p>Abstract</p> <p>Background</p> <p>Mild hypophosphatasia (HPP) phenotype may result from <it>ALPL </it>gene mutations exhibiting residual alkaline phosphatase activity or from severe heterozygous mutations exhibiting a dominant negative effect. In order to determine the cause of our failure to detect a second mutation by sequencing in patients with mild HPP and carrying on a single heterozygous mutation, we tested the possible dominant effect of 35 mutations carried by these patients.</p> <p>Methods</p> <p>We tested the mutations by site-directed mutagenesis. We also genotyped 8 exonic and intronic <it>ALPL </it>gene polymorphisms in the patients and in a control group in order to detect the possible existence of a recurrent intronic mild mutation.</p> <p>Results</p> <p>We found that most of the tested mutations exhibit a dominant negative effect that may account for the mild HPP phenotype, and that for at least some of the patients, a second mutation in linkage disequilibrium with a particular haplotype could not be ruled out.</p> <p>Conclusion</p> <p>Mild HPP results in part from compound heterozygosity for severe and moderate mutations, but also in a large part from heterozygous mutations with a dominant negative effect.</p

TWEAK Appears as a Modulator of Endometrial IL-18 Related Cytotoxic Activity of Uterine Natural Killers

BACKGROUND: TWEAK (Tumor necrosis factor like WEAK inducer of apoptosis) is highly expressed by different immune cells and triggers multiple cellular responses, including control of angiogenesis. Our objective was to investigate its role in the human endometrium during the implantation window, using an ex-vivo endometrial microhistoculture model. Indeed, previous results suggested that basic TWEAK expression influences the IL-18 related uNK recruitment and local cytotoxicity. METHODOLOGY/PRINCIPAL FINDINGS: Endometrial biopsies were performed 7 to 9 days after the ovulation surge of women in monitored natural cycles. Biopsies were cut in micro-pieces and cultured on collagen sponge with appropriate medium. Morphology, functionality and cell death were analysed at different time of the culture. We used this ex vivo model to study mRNA expressions of NKp46 (a uNK cytotoxic receptor) and TGF-beta1 (protein which regulates uNK cytokine production) after adjunction of excess of recombinant IL-18 and either recombinant TWEAK or its antibody. NKp46 protein expression was also detailed by immunohistochemistry in selected patients with high basic mRNA level of IL-18 and either low or high mRNA level of TWEAK. The NKp46 immunostaining was stronger in patients with an IL-18 over-expression and a low TWEAK expression, when compared with patients with both IL-18 and TWEAK high expressions. We did not observe any difference for TWEAK expression when recombinant protein IL-18 or its antibody was added, or conversely, for IL-18 expression when TWEAK or its antibody was added in the culture medium. In a pro-inflammatory environment (obtained by an excess of IL-18), inhibition of TWEAK was able to increase significantly NKp46 and TGF-beta1 mRNA expressions. CONCLUSIONS/SIGNIFICANCE: TWEAK doesn't act on IL-18 expression but seems to control IL-18 related cytotoxicity on uNK cells when IL-18 is over-expressed. Thus, TWEAK appears as a crucial physiological modulator to prevent endometrial uNK cytotoxicity in human

Alterations de la regulation de la lipolyse dans les adipocytes de rats surrenalectomises : recherche des mecanismes impliques

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

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

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 variabilirostris (Crustacea: Decapoda: Atyidae), a new species of freshwater shrimp from Pohnpei (Micronesia)

International audienceRecently, the status of a new species of atyid shrimp from Pohnpei (Micronesia) was discussed in relation to C. brachydactyla De Man, 1908 and C. mertoni J. Roux, 1911. By combining morphological data with a phylogenetic analysis with closely related species, this species is here described as Caridina variabilirostris sp. nov. Notes on its ecological distribution are also provided. The new species is characterized by a highly variable rostrum and is present in rivers all over Pohnpei Island. The status of this new species is clarified and it is shown that neither C. brachydactyla De Man 1908 nor C. mertoni J. Roux, 1911 occur on Pohnpei Island

Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography

International audienceCaridina weberi, an emblematic species of the ‘C. weberi complex’, was described by De Man in 1892 from different localities in Indonesia. Until now, this species was thought to have a wide distribution in Polynesia. Numerous specimens identified as C. weberi were collected recently from various Polynesian islands. In the context of integrative taxonomy, they were morphologically and genetically studied. Three new species allied to C. weberi are here described: C. marquesensis n. sp., C. futunensis n. sp. and C. tupaia n. sp. The occurrence of C. rapaensis, another species part of the ‘C. weberi’ complex is confirmed. Descriptions or redescription of these species are given as well as their geographical and ecological distributions. The position of these species in the complex is clarified. A key is provided to facilitate identification

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

Caridina rapaensis Edmondsoni 1935

&lt;i&gt;Caridina rapaensis&lt;/i&gt; Edmondson&imath; 1935 (Figure 6) &lt;p&gt; &lt;i&gt;Caridina rapaensis&lt;/i&gt; Edmondson 1935: 12, 14, Figure 5 (a &lt;i&gt;&ndash;&lt;/i&gt; h) page 15; Marquet 1988, 1991: 130; Poupin 1998: 8; Keith and Vigneux 2002: 125, photos 3 &amp; 4; Keith et al. 2002: 40 &lt;i&gt;&ndash;&lt;/i&gt; 41; Keith et al. 2013, p. 78 &lt;i&gt;&ndash;&lt;/i&gt; 79.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Material observed&lt;/i&gt;&lt;/p&gt; &lt;p&gt; &lt;i&gt;Type material.&lt;/i&gt; Holotype: 1 &female;, cl 4.7 mm, 1934, a freshwater stream, Rapa Island, French Polynesia, Mangarevan Expedition coll., BPBM 53933.&lt;/p&gt; &lt;p&gt;Paratype: 1 &female;, cl 5.0 mm, same data as holotype, BPBM 53694.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Other material&lt;/i&gt;. 1 &male;, cl 3.3 mm, 15 June 2001, 27&deg;35.919 &lt;i&gt;&prime;&lt;/i&gt; S 144&deg;20.392 &lt;i&gt;&prime;&lt;/i&gt; W, Panui stream, Rapa Island, French Polynesia, altitude 18m, G. Marquet coll., MNHN-IU-2016-11768; 1 &male;, cl 3.4 mm, same data as previous, MNHN-IU-2016-11769 (DNA: CA2114); 1 &female;, cl 4.8 mm, same data as previous, MNHN-IU-2016-11770; 1 &female;, cl 5.2 mm, same data as previous, MNHN-IU-2016-11771 (DNA: CA2115); 1 &female;, cl 6.0 mm, same data as previous, MNHN-IU -2016-11772 (DNA: CA2111); 2 &male;, cl 2.5 &lt;i&gt;&ndash;&lt;/i&gt; 2.9 mm and 2 &female; ovig, cl 4.0 &lt;i&gt;&ndash;&lt;/i&gt; 4.6 mm, 2 May 1986, 22&deg;26.240 &lt;i&gt;&prime;&lt;/i&gt; S 151&deg;22.243 &lt;i&gt;&prime;&lt;/i&gt; W, Tevaovai stream, Rurutu Island, French Polynesia, altitude 52m, G. Marquet coll., MNHN-IU-2015 &lt;i&gt;&ndash;&lt;/i&gt; 1921.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Comparative material&lt;/i&gt;. Type material&lt;/p&gt; &lt;p&gt; &lt;i&gt;Caridina parvirostris&lt;/i&gt; De Man, 1892.&lt;/p&gt; &lt;p&gt; Syntypes: 2 &female;, cl. 3.1 &lt;i&gt;&ndash;&lt;/i&gt; 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.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Caridina weberi&lt;/i&gt; var. &lt;i&gt;keiensis&lt;/i&gt; Roux, 1911&lt;/p&gt; &lt;p&gt;Lectotype: 1 &female; ovig. cl 5.7mm, 5 June 1908, Warka, Grand Kei Island, Indonesia, H. Merton coll., NMB 6.IV.b.&lt;/p&gt; &lt;p&gt;Paralectotypes: 2 &male; cl 2.6mm, 1 &male; 6.IV.b, same data as for lectotype, NMB 6.IV.a; 1 &female;, cl 5.5mm and 1 &male;, cl 3.4mm, same data as for lectotype, NMB 6.IV.b.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Caridina weberi&lt;/i&gt;, 1892.&lt;/p&gt; &lt;p&gt; Syntypes: 2 &male;, cl 4.4 &lt;i&gt;&ndash;&lt;/i&gt; 4.5 mm and 1 &female; ovig, cl 6.1 mm, Kotting, Flores Island, Indonesia, M. Weber coll., MNHN-IU-2015-1755.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Description&lt;/i&gt;&lt;/p&gt; &lt;p&gt; &lt;i&gt;Cephalothorax.&lt;/i&gt; Rostrum (Figure 6 (h)) always bent down, short, 0.3 &lt;i&gt;&ndash;&lt;/i&gt; 0.5 of cl, reaching to base of second segment of antennular peduncle, armed dorsally with 0 &lt;i&gt;&ndash;&lt;/i&gt; 5 teeth, occupying distal fourth of border, none situated on carapace posterior to orbital margin, ventral margin with 1 &lt;i&gt;&ndash;&lt;/i&gt; 6 teeth. Rostral formula (0) 0 &lt;i&gt;&ndash;&lt;/i&gt; 5/1 &lt;i&gt;&ndash;&lt;/i&gt; 6. Suborbital angle indistinguishably fused with antennular tooth. Pterygostomian margin rounded.&lt;/p&gt; &lt;p&gt;Eyes well developed, anterior end reaching to 0.77 length of antennular peduncle basal segment. Antennular peduncle 0.44 times as long as carapace. Anterolateral angle of basal antennular segment reaching 0.20 length of second antennular segment, second antennular segment distinctly longer than third. Stylocerite reaching to end of antennular peduncle basal segment. Scaphocerite reaching just slightly beyond tip of antennular peduncle, about 3.1 times longer than wide.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Mouthparts.&lt;/i&gt; Left mandible, right mandible, first maxilla, second maxilla, first maxilliped, second maxilliped and third maxilliped typical of genus.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Pereiopods.&lt;/i&gt; Epipods on first four pereiopods.&lt;/p&gt; &lt;p&gt; Pereiopod 1 (Figure 6 (a)): chela about 1.5 &lt;i&gt;&ndash;&lt;/i&gt; 2.5 times as long as wide, movable finger 1.5 &lt;i&gt;&ndash;&lt;/i&gt; 4.4 times as long as wide, 0.5 &lt;i&gt;&ndash;&lt;/i&gt; 1.4 times length of palm, carpus 1.2 &lt;i&gt;&ndash;&lt;/i&gt; 1.7 times as long as wide. Tips of both fingers with prominent claws (Figure 6 (b)).&lt;/p&gt; &lt;p&gt; Pereiopod 2 (Figure 6 (c)): more slender and long than the first pereiopod with chela 2.0 &lt;i&gt;&ndash;&lt;/i&gt; 2.7 times as long as wide: movable finger 3.2 &lt;i&gt;&ndash;&lt;/i&gt; 4.7 times as long as wide, 1.3 &lt;i&gt;&ndash;&lt;/i&gt; 1.9 times length of palm, carpus slender 4.2 &lt;i&gt;&ndash;&lt;/i&gt; 5.2 times as long as wide.&lt;/p&gt; &lt;p&gt; Pereiopod 3 (Figure 6 (d, g)): stout, dactylus 2.7 &lt;i&gt;&ndash;&lt;/i&gt; 3.9 times as long as wide including terminal spine with 6 &lt;i&gt;&ndash;&lt;/i&gt; 8 spines including terminal spine, propodus 9.0 &lt;i&gt;&ndash;&lt;/i&gt; 12.8 times as long as wide, 3.9 &lt;i&gt;&ndash;&lt;/i&gt; 4.9 times as long as dactylus.&lt;/p&gt; &lt;p&gt; Pereiopod 5 (Figure 6 (e, f)): dactylus 3.1 &lt;i&gt;&ndash;&lt;/i&gt; 4.9 as long as wide, ending in two large claws with 30 &lt;i&gt;&ndash;&lt;/i&gt; 45 spiniform setae on flexor margin, propodus 11.7 &lt;i&gt;&ndash;&lt;/i&gt; 19.0 times as long as wide, with numerous spines on ventral margin, 4.5 &lt;i&gt;&ndash;&lt;/i&gt; 5.4 times as long as dactylus.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Abdomen.&lt;/i&gt; Third abdominal somite with moderarely convex dorsal profile. Sixth abdominal somite about 0.4 times carapace length, 1.2 times as long as fifth somite, shorter than telson. Telson (Figure 6 (k)): 2.9 times as long as wide, with five or six pairs of dorsal spines and one pair of dorsolateral spines, posterior margin with small median process, rounded with 5 &lt;i&gt;&ndash;&lt;/i&gt; 13 intermediate plumose setae much longer than lateral spines.&lt;/p&gt; &lt;p&gt;First male pleopod (Figure 6 (m)): Endopod extending to 0.42 times length of exopod, rectangular, with a short appendix interna near distal end of endopod.&lt;/p&gt; &lt;p&gt;Second male pleopod (Figure 6 (n)): Appendix masculina reaching 0.83 times length of endopod, appendix interna reaching about 0.34 times appendix masculina length.&lt;/p&gt; &lt;p&gt;Preanal carina (Figure 6 (i)): High, unarmed.&lt;/p&gt; &lt;p&gt; Uropodal diaeresis (Figure 6 (k)): with 15 &lt;i&gt;&ndash;&lt;/i&gt; 20 spinules.&lt;/p&gt; &lt;p&gt; Eggs (Figure 6 (j)): Size 0.44 &lt;i&gt;&ndash;&lt;/i&gt; 0.49 &times; 0.26 &lt;i&gt;&ndash;&lt;/i&gt; 0.29 mm.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Habitat&lt;/i&gt;&lt;/p&gt; &lt;p&gt;This new species prefers fresh and well-oxygenated running waters from the lower course to the middle course.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Colour pattern (Figure 7 (d&imath; e))&lt;/i&gt;&lt;/p&gt; &lt;p&gt;The live general colour of the body is yellowish to greenish and slightly translucent. Numerous red spots are visible all over the body.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Distribution (Figure 8)&lt;/i&gt;&lt;/p&gt; &lt;p&gt;This species is known only from Austral Islands (Rurutu and Rapa islands) so far and seems to be endemic.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Remarks&lt;/i&gt;&lt;/p&gt; &lt;p&gt; Our specimens look like those described by Edmondson (1935): Rostrum always bent down, short, 0.3 &lt;i&gt;&ndash;&lt;/i&gt; 0.5 of cl, reaching to base of second segment of antennular peduncle (vs rostrum slender, slightly turned down, reaching to the middle of the second segment of the antennular peduncle for Edmondson (1935)), rostrum armed with 0 &lt;i&gt;&ndash;&lt;/i&gt; 5 teeth on dorsal margin, occupying the distal fourth of the border, ventral margin with 1 &lt;i&gt;&ndash;&lt;/i&gt; 6 teeth. (vs rostral teeth small and few, stronger above than below, those above occupying the distal fourth of the border, the first (basal) tooth below being posterior to the first one of the upper border for Edmondson (1935)), P1 finger 0.5 &lt;i&gt;&ndash;&lt;/i&gt; 1.4 times length of palm (vs dactylus as long as upper border of palm for Edmondson (1935)), P3 dactylus with 6 &lt;i&gt;&ndash;&lt;/i&gt; 8 spines on flexor margin in addition to the terminal spine (vs border dactylus provided with a stout tooth just proximal of the tip, and four other small spines for Edmondson (1935)), P5 dactylus ending in two large claws with 30 &lt;i&gt;&ndash;&lt;/i&gt; 45 spiniform setae on flexor margin (vs dactylus of fifth leg bearing numerous short hairs and a strong supplementary tooth near the tip for Edmondson (1935)), posterior margin of the telson with a little median process, rounded with 5 &lt;i&gt;&ndash;&lt;/i&gt; 13 intermediate plumose setae much longer than lateral spines (vs telson with 6 pairs of small spines on upper border, its posterior margin bearing a small median tooth for Edmondson (1935)), and uropodal diaeresis with 15 &lt;i&gt;&ndash;&lt;/i&gt; 20 spinules (vs uropodal spinelets 20 in number for Edmondson (1935)).&lt;/p&gt; &lt;p&gt; This species differs from &lt;i&gt;C. parvirostris&lt;/i&gt; by its bent rostrum with fewer dorsal teeth (0 &lt;i&gt;&ndash;&lt;/i&gt; 5) (vs bent rostrum with 8 &lt;i&gt;&ndash;&lt;/i&gt; 10 dorsal teeth in &lt;i&gt;C. parvirostris&lt;/i&gt;) and its P2 carpus shorter 4.2 &lt;i&gt;&ndash;&lt;/i&gt; 5.2 times as long as wide (vs 6.0 &lt;i&gt;&ndash;&lt;/i&gt; 7.4 in &lt;i&gt;C. parvirostris&lt;/i&gt;) and so is P2 chela 2.0 &lt;i&gt;&ndash;&lt;/i&gt; 2.7 times as long as wide (vs 2.6 &lt;i&gt;&ndash;&lt;/i&gt; 3.0 in &lt;i&gt;C. parvirostris&lt;/i&gt;).&lt;/p&gt; &lt;p&gt; This species differs from &lt;i&gt;C. futunensis&lt;/i&gt; n. sp. by its bent rostrum with fewer dorsal teeth (0 &lt;i&gt;&ndash;&lt;/i&gt; 5) (vs bent rostrum with 5 &lt;i&gt;&ndash;&lt;/i&gt; 10 in &lt;i&gt;C. futunensis&lt;/i&gt; n. sp.) and its P5 dactylus ending in two large claws (vs one large claw in &lt;i&gt;C. futunensis&lt;/i&gt; n. sp.).&lt;/p&gt; &lt;p&gt; &lt;i&gt;C. rapaensis&lt;/i&gt; was reported by Shokita (2003) from Ryukyu Islands, but according to Cai and Shokita (2006), these specimens actually belong to &lt;i&gt;C. prashadi&lt;/i&gt; Tiwari &amp; Pilai, 1971 described from the Andaman Islands. Indeed, even if the rostrum formula is similar (0) 0 &lt;i&gt;&ndash;&lt;/i&gt; 5/1 &lt;i&gt;&ndash;&lt;/i&gt; 6 (vs (0)1 &lt;i&gt;&ndash;&lt;/i&gt; 6/ 3 &lt;i&gt;&ndash;&lt;/i&gt; 6 in &lt;i&gt;C. prashadi&lt;/i&gt;), &lt;i&gt;C. rapaensis&lt;/i&gt; can be distinguished easily from &lt;i&gt;C. prashadi&lt;/i&gt; by its prominent claws on the tips of both P1 fingers (vs no prominent claws in &lt;i&gt;C. prashadi&lt;/i&gt;) and by its P5 dactylus ending in two large claws (vs one claw in &lt;i&gt;C. prashadi&lt;/i&gt;) with 30 &lt;i&gt;&ndash;&lt;/i&gt; 45 spiniform setae on flexor margin (vs 29 in &lt;i&gt;C. prashadi&lt;/i&gt;).&lt;/p&gt; &lt;p&gt; &lt;i&gt;C. rapaensis&lt;/i&gt; looks like &lt;i&gt;C. weberi&lt;/i&gt; var. &lt;i&gt;keiensis&lt;/i&gt; from Kei Islands (Indonesia) by its bent and short rostrum, its P1 chela bearing prominent claws and its P5 dactylus being biunguiculate. However, they can be distinguished by the number of dorsal teeth on the rostrum 0 &lt;i&gt;&ndash;&lt;/i&gt; 5 (vs 2 &lt;i&gt;&ndash;&lt;/i&gt; 13 in &lt;i&gt;C. weberi&lt;/i&gt; var. &lt;i&gt;keiensis&lt;/i&gt;). Furthermore, considering the distance between Kei Islands and Polynesia and that &lt;i&gt;C. weberi&lt;/i&gt; var. &lt;i&gt;keiensis&lt;/i&gt; has never been collected in between, we consider it to be a distinct species.&lt;/p&gt;Published as part of &lt;i&gt;Mazancourt, Valentin de, Marquet, Gérard &amp; 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)&lt;/i&gt; on pages 832-838, DOI: 10.1080/00222933.2019.1612959, &lt;a href="http://zenodo.org/record/3675643"&gt;http://zenodo.org/record/3675643&lt;/a&gt