Search

Funder: Australian National Environmental Science Foundation, Funder: Corpus Christi College; Id: http://dx.doi.org/10.13039/501100000591, Funder: IOP PAN, We identified 14 emerging and poorly understood threats and opportunities for addressing the global conservation of freshwater mussels over the next decade. A panel of 17 researchers and stakeholders from six continents submitted a total of 56 topics that were ranked and prioritized using a consensus-building Delphi technique. Our 14 priority topics fell into five broad themes (autecology, population dynamics, global stressors, global diversity, and ecosystem services) and included understanding diets throughout mussel life history; identifying the drivers of population declines; defining metrics for quantifying mussel health; assessing the role of predators, parasites, and disease; informed guidance on the risks and opportunities for captive breeding and translocations; the loss of mussel-fish co-evolutionary relationships; assessing the effects of increasing surface water changes; understanding the effects of sand and aggregate mining; understanding the effects of drug pollution and other emerging contaminants such as nanomaterials; appreciating the threats and opportunities arising from river restoration; conserving understudied hotspots by building local capacity through the principles of decolonization; identifying appropriate taxonomic units for conservation; improved quantification of the ecosystem services provided by mussels; and understanding how many mussels are enough to provide these services. Solutions for addressing the topics ranged from ecological studies to technological advances and socio-political engagement. Prioritization of our topics can help to drive a proactive approach to the conservation of this declining group which provides a multitude of important ecosystem services.

A new diving beetle, Copelatus mkambati sp. nov., is described from the Mkambati Nature Reserve in the Eastern Cape Province, South Africa. The new species is compared with other Afrotropical taxa with two elytral striae and no submarginal stria (the macellus species group of Copelatus Erichson, 1832). A combination of small eyes, rather weak pigmentation, flattened, subparallel habitus, relatively large head and collecting circumstances all suggest that the new species may be semisubterranean in lifestyle.

The ephemeral waterbodies of southern Africa are regarded a global hotspot for large Branchiopod diversity. Although the distributions and systematics of Anostraca and Notostraca have been fairly well defined, clam shrimps have received much less attention. So far, 18 clam shrimp species are known from the sub-region, but none of the available published literature defines their distribution in South Africa. Furthermore, most of the recent studies were concentrated in the mesic provinces, while very little information is available from the Northern Cape, where most ephemeral waterbodies in the country occur. This study reviews the distribution of clam shrimps in South Africa by reviewing published distribution records and contributing novel data from surveys in the Northern Cape. We found that 13 of the 18 species from the sub-region occur in South Africa, of which four are restricted to their respective provinces. We further clarify the current state of endemism patterns in South Africa and provide novel findings from the Northern Cape, including three new range extensions. The Northern Cape hosts the highest species richness, with nine species, followed by the Eastern Cape, where seven species have been recorded so far. Most other provinces have low species richness and endemism, while no species records have been published from the Limpopo province yet. Surveys over large geographical scales are important, and more research is needed on clam shrimp systematics in South Africa.

Mesoceration explanatum sp. nov. Type locality. South Africa, Western Cape Province, Piketberg, stream below Sebrakop, 32�� 46 19.35S 18 45 42.09E, 809 m. Type material. Holotype (male): " 3/x/2015 South Africa WC// Piketberg - stream below// Sebrakop 32�� 46��� 19.35������S 18�� 45��� 42.09������E 809 m // D T Bilton leg." (genitalia extracted and mounted on same card) and red holotype label (AMG). Paratypes (30): South Africa: 8♂, 5♀ same data as holotype; 2♀ " 3/x/2015 South Africa, WC// Piketberg - stream in bowl below// Sebrakop 32 46 12.61S // 18 45 48.59E 876 m // D T Bilton leg."; 5♂, 3♀ " 4/x/2015 South Africa WC// Piketberg - stream flowing NW// below Sebrakop 32 45 30.28S // 18 45 50.74E 952 m // D T Bilton leg."; 3♂, 4♀ " 4/x/2015 South Africa WC// Piketberg - stream flowing SE// below Sebrakop 32 45 53.73S 18 45// 56.01E 943 m // D T Bilton leg." (AMG, CDTB, ISAM, NMW, SANC, TMSA). Description. Size: Holotype: BL 1.93 mm; EL 1.12 mm; EW 0.73 mm. Paratypes: Males BL 1.69���1.97 mm; EL 0.96���1.1 mm; EW 0.63���0.70 mm. Females BL 1.82���1.93 mm; EL 1.0 6��� 1.12 mm; EW 0.68���0.72 mm. Colour: Dorsum (Fig. 1A) pitchy brown to black, apex of elytra and ocelli somewhat paler. Legs orange brown; apical tarsal segments infuscated. Maxillary palpi pale orange brown, apical segment infuscated. Venter pitchy brown to black, with silvery hydrofuge vestiture. Mentum, submentum, pronotal hypomeron, epipleurs and pseudepipleurs paler. Head: Labrum slightly transverse, broadly rounded apicolaterally with broad apicomedian emargination occupying approx. 0.5 of length. Sides of apicomedian emargination weakly raised. Surface of labrum shining, microreticulate, meshes elongate at sides, transverse and smaller basally and close to centre; with scattered, white, recumbent setae, particularly close to apicolateral angles. Frontoclypeal suture distinct, weakly arcuate, becoming obsolete laterally. Clypeus, frons and vertex somewhat dull, with rugulose microreticulation of transverse to isodiametric meshes and sparse, medium punctures bearing short, white, recumbent setae; reticulation and punctation especially strong on frons and vertex. Anteocular sulci broad, shallow, running from ocelli to frontoclypeal suture, open anterolaterally. Ocelli small and shining; head behind ocelli with sharp declivity. Compound eyes relatively small, occupying approx. 0.4 side of head, 12 ocelli in longest series. Pronotum: Cordate, slightly transverse, broadest just before middle. Anterior margin arcuate over median 0.5, without hyaline border; posterior margin bisinuate around centre. Anterior angles obtusely rounded; posterior angles slightly obtuse, weakly rounded. Lateral margins sinuated from widest point to base, broadly marginated and weakly serrate. Surface dull, strongly microreticulate, with isodiametric to slightly transverse meshes, weakly granulose on reliefs; reliefs with dense, coarse punctures bearing white, recumbent setae. With 10 distinct foveae as follows: anterior median fovea elongate, deeper and broader posteriorly; posterior median fovea oval, approx. 0.5 length of anterior. Anterior admedian foveae short oval, open anterolaterally; posterior admedian foveae elongate, open anterolaterally. Anterior adlateral foveae deep, oval, open laterally; posterior adlateral foveae deep, elongate oval, open laterally. Elytra: Elongate oval, broadest just behind middle. Subparallel over median 0.4, then weakly attenuated to broadly truncate, cojointly emarginate hind angles. Dorsally flattened with shallow posterior declivity. Lateral margins broadly explanate; weakly serrate, at least anteriorly. Elytral series of coarse, moderately shallow punctures, evident to apex; larger in anterior 0.5, becoming smaller posteriorly. Serial punctures with fine decumbent setae, not usually reaching next puncture in row. Discal series weakly striate impressed. Series 1 and 2 confluent behind posterior declivity; series 5 and 6 confluent in anterior 0.4. Interval 8 strongly carinate from just behind shoulder to approx. 0.1 from apex. Intervals shining, granulate, bearing white decumbent setae. Legs: Apical protarsomere with two stout ventral setae; basal three protarsomeres with suction setae. Wings: Full. Venter: Mentum and submentum shining, microreticulate with weakly impressed, slightly transverse meshes; mentum with short, stout yellow recumbent to erect setae around anterior margins. Genae shining, weakly microreticulate; meshes tranverse. Gula shining in centre, with weak transvere furrows; laterally with fine, rugulose microreticulation. Prosternum with narrow, shining, glabrous central ridge; remainder rugulose, with dense hydrofuge vestiture. Pronotal hypomeron broad, shining, with fine, elongate microreticulation and small foveae situated anterior to anterior margin of procoxae. Mesoventrite and metaventrite with dense hydrofuge vestiture. Mesoventral plaques weak, forming an inverted Y, stem 0.5 length of arms. Traces of admedian and adlateral ridges visible. Metaventrite with oval median fovea over posterior 0.6 and shallow depressions anterior, below mesocoxae. Elytral pseudepipleurs shining, with fine, sparse punctures and no microreticulation; epipleurs narrow, shining, ridge-like to apex. Abdominal ventrites 1-4 with dense hydrofuge vestiture. Abdominal ventrite 5 with hydrofuge vestiture anterolaterally; broad, arcuate posterior patch glabrous, with fine, transverse microreticulation; irregular transverse row of fine punctures bearing long, fine, decumbent setae evident laterally, close to posterior margin. Abdominal ventrite 6 glabrous, with fine, transverse microreticulation; irregular transverse row of fine punctures bearing long, fine, decumbent setae towards posterior margin; apex weakly emarginate at centre. Aedeagus: Elongate, relatively broad in ventral view, with parameres attaching close to base and extending just beyond apex of main piece. Main piece with characteristically shaped, asymmetrical apex. Distal lobe elongate, curving strongly to the left, then apically in ventral view (Fig. 2A). Female: Slightly broader than male, particularly towards the apex of the elytra; explanate elytral margins broader. Abdominal ventrite 7 produced to bluntly rounded apex. Variation: Paratypes show some variation in extent of pale colouration at lateral margins of the elytra, yellowish to shoulder in some specimens. Differential diagnosis. A member of the truncatum group sensu Perkins & Balfour-Browne (1994), the elytra having well developed posterolateral angles, and truncate apices. In this work M. explanatum sp. nov. would key to M. brevigranum Perkins & Balfour-Brown, 1994, on the basis of its granulose pronotal reliefs. The new species differs from M. brevigranum in the much broader pronotum, and the more strongly truncate, cojointly emarginate, elytral apices. These characters also readily distinguish it from M. granulovestum Perkins, 2008, M. umbrosum Perkins, 2008. M. rugulosum Bilton, 2015 and M. castaneum Bilton, 2017 also have relatively broad pronota, but have much less truncate elytral apices. The aedeagus of M. explanatum sp. nov. is characteristic, with a uniquely shaped main piece. Distribution. To date only known from the Piketberg massif in the Western Cape Province, where it was, however, abundant in all four streams sampled for water beetles, all of which were above 800 m a.s.l. Here it occurred with a relatively diverse water beetle assemblage, including M. hirsutum Bilton, 2015, a species previously only known from the holotype, collected at close to 1,000 m a.s.l. in the Cederberg range. Etymology. Named in reference to the broadly explanate elytra., Published as part of Bilton, David T. & Mlambo, Musa C., 2019, Two new Mesoceration Janssens, 1967 from the Piketberg, South Africa (Coleoptera, Hydraenidae), pp. 268-274 in Zootaxa 4555 (2) on pages 269-271, DOI: 10.11646/zootaxa.4555.2.7, http://zenodo.org/record/2624353, {"references":["Perkins, P. D. & Balfour-Browne, J. (1994) A contribution to the taxonomy of aquatic and humicolous beetles of the family Hydraenidae in southern Africa. Fieldiana Zoology, 77, 1 - 159.","Perkins, P. D. (2008). New species and new collection records of Prosthetopine water beetles from southern Africa (Coleoptera: Hydraenidae). Zootaxa, 1864, 1 - 124.","Bilton, D. T. (2015) New species and new records of Mesoceration from South Africa (Coleoptera: Hydraenidae). Zootaxa, 3972 (4), 495 - 520. https: // doi. org / 10.11646 / zootaxa. 3972.4.3","Bilton, D. T. (2017) Water beetles from the Bokkeveld Plateau: a semi-arid hotspot of freshwater biodiversity in the Northern Cape of South Africa. Zootaxa, 4268 (2), 191 - 214. https: // doi. org / 10.11646 / zootaxa. 4268.2.2"]}

Mesoceration piketbergense sp. nov. Type locality. South Africa, Western Cape Province, Piketberg, stream below Sebrakop, 32�� 46��� 19.35������S // 18�� 45��� 42.09������E, 809 m. Type material. Holotype (male): " 3/x/2015 South Africa WC// Piketberg - stream below// Sebrakop 32 46 19.35S // 18 45 42.09E 809 m // D T Bilton leg." (genitalia extracted and mounted on same card) and red holotype label (AMG). Paratypes (20): South Africa: 5♂, 15♀, same data as holotype. Description. Size: Holotype: BL 1.90 mm; EL 1.12 mm; EW 0.63 mm. Paratypes: Males BL 1.80���1.96 mm; EL 1.05���1.15 mm; EW 0.60���0.65 mm. Females BL 1.75���1.95 mm; EL 1.05���1.10 mm; EW 0.60���0.65 mm. Colour: Dorsum (Fig. 1B) black with a rim of dark yellow-brown on the anterior margins of labrum. Anterior and posterior margins of pronotum and lateral margins of elytra dark brown; ocelli dark brown. Maxillary palps pale yellow, last segment slightly infuscated over apical 0.6. Legs orange brown. Venter black with silvery hydrofuge vestiture. Prementum pale brown; submentum darkish brown; gena black; gula black, slightly paler basally. Head: Labrum slightly transverse, rounded apicolaterally with broad apicomedian emargination running approx. 0.4 of length. Surface shining with fine microreticulation; elongate in centre, isodiametric basally; with scattered fine punctures bearing recumbent setae. Frontoclypeal suture obsolete. Clypeus with strong, transverse microreticulation over central part, and scattered, medium punctures bearing short, white recumbent setae. Frons and vertex dull, with strong granulate microreticulation and scattered medium punctures bearing white recumbent setae. Ocelli small, shining. Head behind ocelli with sharp declivity. Anteocular sulci broad, shallow, open apicolaterally. Compound eyes small, occupying ca. 0.35 side of head; 10 ommatidia in longest series. Pronotum: Cordate, slightly transverse, broadest before middle. Anterior margin arcuate over median 0.5, no hyaline border; posterior margin bisinuate around centre. Anterior angles obtusely rounded; posterior angles obtuse and weakly rounded. Lateral margins sinuated from widest point to base, broadly marginated and moderately serrate. Surface dull, with dense coarse punctures bearing long, fine, decumbent setae. Relief with shining granulate microreticulation. With 10 foveae as follows: anterior median fovea elongate, posterior median fovea elongate oval, both deepest in centre and confluent. Anterior admedian foveae shallow, oval, open anteriorly; posterior admedian foveae deeper, elongate oval, orientated anterolaterally. Anterior adlateral foveae oval, shallow, open apicolaterally. Posterior adlateral foveae small, oval, open anterolaterally. Elytra: Elongate oval, broadest at middle, subparallel over anterior 0.5 then attenuated to acuminate, rounded apices. Apical angles rounded, slightly emarginated around suture. Punctures of elytral series relatively coarse, larger in anterior 0.5 and smaller and shallower posteriorly. Serial punctures with fine decumbent setae, not usually reaching next puncture in row. Weakly striate impressed on disc, especially series 1 and 2. Series 1 and 2 confluent immediately behind posterior declivity, at ca. 0.65 of length; series 5 and 6 confluent anteriorly, at ca. 0.25 of length. Intervals shining, with weak granules, bearing long, white, recumbent to decumbent setae. Legs: Apical protarsomere with two stout ventral setae; basal three protarsomeres with suction setae. Wings: Reduced, approx. 0.5 length of elytra when extended. Venter: Mentum weakly shining, with rugulose microreticulation, meshes elongate along lateral margins and isodiametric in centre; surface with scattered, erect setae, particularly around front margins. Submentum with transverse microreticulation and scattered medium punctures with long recumbent setae. Genae shining, with transverse microreticulation anteriorly, covered with dense hydrofuge vestiture posteriorly. Gula weakly shining, with weak transverse microreticulation. Prosternum with glabrous ridge anteriorly, covered with transverse microreticulation and metaventrite covered with dense hydrofuge vestiture. Pronotal hypomeron broad, weakly shining with fine isodiametric microreticulation. Mesoventral plaques glabrous, forming inverted Y; admedian and adlateral ridges visible but weak. Metaventrite with shallow, elongate median fovea over posterior 0.5 and shallow oval depressions below mesocoxae; posterior margin emarginated at centre, here devoid of hydrofuge vestiture. Abdominal ventrite 5 with dense hydrofuge vestiture over anterior 0.65; glabrous posteriorly, with transverse microreticulation. Abdominal ventrite 6 entirely glabrous with weak transverse microreticulation and an irregular transverse row of long recumbent setae. Aedeagus: Elongate, parameres attached near the base. Parameres extend beyond the main piece, to approximately 0.5 length of distal lobe. Main piece with strong, elongate tooth on left side in ventral view. Distal lobe elongate, narrow, strongly angled to the left in ventral view (see Fig. 2B). Female: Broader than male, especially on elytra, with more broadly explanate lateral margins. Elytral apex more strongly acuminate. Abdominal ventrite 5 with broad, glabrous patch with weak transverse microreticulation over central 0.5, tumid laterally at apical margin. Variation: Some specimens slightly paler than holotype. Differential diagnosis. A member of the endroedyi group sensu Perkins & Balfour-Browne (1994). In this work the species would key to Mesoceration concessum Perkins & Balfour-Browne, 1994, being apparently close to this species and Mesoceration tabulare Perkins, 2008. M. piketbergense sp. nov. differs from M. concessum in having a more strongly microreticulate pronotum, which is granulate on the reliefs, and denser, coarser punctures on the frons and vertex. In the new species the granules of the elytral intervals are smaller than those in M. concessum, being closer in this character to M. tabulare. The three species can readily be distinguished on aedeagal characters, particularly details of the apex of the main piece and the shape of the distal lobe. All three species are brachypterous (Perkins & Balfour-Browne 1994; Perkins 2008). Distribution. So far only known from the Piketberg range, a westerly outlier of the north-south trending mountains of the Western Cape Province, South Africa. Here it was found in only one of the four streams sampled in 2015, where it was, however, abundant. As with M. concessum and M. tabulare, the species brachyptery may explain its apparent geographical restriction. Etymology. Named in reference to the Piketberg range, in which the type locality is situated., Published as part of Bilton, David T. & Mlambo, Musa C., 2019, Two new Mesoceration Janssens, 1967 from the Piketberg, South Africa (Coleoptera, Hydraenidae), pp. 268-274 in Zootaxa 4555 (2) on pages 273-274, DOI: 10.11646/zootaxa.4555.2.7, http://zenodo.org/record/2624353, {"references":["Perkins, P. D. & Balfour-Browne, J. (1994) A contribution to the taxonomy of aquatic and humicolous beetles of the family Hydraenidae in southern Africa. Fieldiana Zoology, 77, 1 - 159.","Perkins, P. D. (2008). New species and new collection records of Prosthetopine water beetles from southern Africa (Coleoptera: Hydraenidae). Zootaxa, 1864, 1 - 124."]}

Caridina natalensis De Man, 1908 Caridina nilotica var. natalensis De Man, 1908: 262 ���263 pl.20, fig.3, 3a, 3b; Lenz, 1912: 5; Bouvier, 1925: 154 ���155 fig. 320; Barnard, 1950: 655 (key). Caridina longirostris- Richters, 1880:162 ���163; Holthuis, 1965: 20 ���23 fig. 6; Keith et al. 2006: 50 ���51. Caridina nilotica var. brachydactyla- Lenz, 1910: 568; Roux, 1929: 303 ���304 tab.1 no.15. Caridina nilotica var. gracilipes- Lenz, 1910: 568. Caridina brachydactyla brachydactyla - Costa 1980: 673 ���700. Material examined. Type material: Caridina nilotica natalensis De Man, 1908: SOUTH AFRICA. Lectotype (designated by Richard & Clark, 2010). ZMA. CRUS.D. 102886, 1♀ ovig. cl 6.4mm; Umgeni River, Durban, Natal, coll. M. Weber, 1898, det. J.G. De Man. Paralectotypes. ZMA. CRUS.D. 102886, 2♀ ovig. cl 5.7���6.4mm; same data. Caridina nilotica var. brachydactyla De Man, 1908: INDONESIA. Lectotype (designated by Richard & Clark, 2010). RMNH.CRUS.D.977, 1♀ ovig. cl 4.8mm; Near Reo, Flores, coll. M. Weber. Paralectotypes. RMNH. CRUS.D.2552, 2♀ ovig. cl 5.3���5.4mm; river near Palopo Luwu, Sulawesi, coll. M. Weber.. Caridina brevidactyla Roux, 1920: INDONESIA. Lectotype (designated by Richard & Clark, 2010). NMB 4. VI. b 1, 1♂ cl 4,8mm; Sungi Manumbai, Wokam Island, Aru, April 14 ��� 15,1908. Paralectotypes. NMB 4. VI. a, 1♂ cl 3.3mm; Aru, Udjir Island, April 15, 1908, NMB 4. VI. b, 2♀ cl 5.8���6.4mm; Sungi Manumbai, Wokam Island, Aru, April 14 ���15,1908. NMB 0 0 0 0 4 VIc, Wokamar, Wokam Island, Aru, April 17, 1908, 1♀ ovig. 5,7mm; NMB 4. VI. d; 2♀ ovig. cl 5.7mm, Seltutti, Kobroor Island, Aru, May 2, 1908. Caridina gracilipes De Man, 1892: INDONESIA. Paralectotypes. ZMA.CRUS.D. 102635, 1♂ cl 4.1mm (DNA: CA025), 1♀ ovig. cl 5.9mm (DNA: CA023), 3♀ cl 5.1mm (DNA: CA027), 5.2mm (DNA:CA024) and 5.6mm; in a rice field, Makassar, Sulawesi, coll. M. Weber, 1888. NMB 1061e, 1♂ 3.8mm; 2♀ cl 5.8���5.9mm; same data. Caridina longirostris H. Milne Edwards, 1837: ALGERIA. Paralectotypes. MNHN-IU-2013-19419, 3♂ cl 2.9���3.1mm; from the river Macta, near Oran. MNHN IU-2013-19418, 2♂ 3.2���3.6mm; same data. Non- types: Caridina natalensis KENYA. MNHN-IU-2015-1854, Tiwi river, 20km south of Mombasa. TANZANIA. NHM 1982.576, 3♀ ovig. cl 5.5���7.2mm, Ruo Lukuledi, Tanganyika. SOUTH AFRICA. MNHN- IU- 2018-61, 1 ♂ cl 3.3mm (DNA: CA2079) and MNHN-IU- 2018-62, 1♀ ovig. cl 6.0mm, River Mbanyana, 32��13.123'S 28��55.031'E, altitude 9m, coll. Maliwa L., Mlambo M., Marquet G. & Tiberghien, P., February 11, 2018; MNHN-IU- 2018-63, 1♀ ovig. cl 6.9mm and MNHN-IU- 2018-64, 1♀ ovig. cl 6.8mm, River Umtata, altitude 2m, 31��34.144'S, 28��45.523'E, coll. Maliwa L., Mlambo M., Marquet G. & Tiberghien, P., February 13, 2018; MNHN-IU- 2018-65, 1♀ ovig. cl 6.3mm and MNHN-IU- 2018-66, 1♀ ovig. cl 6.3mm (DNA: CA2083), River Mzumbe, altitude 6m, 30��36.151'S 30��32.817'E, coll. Maliwa L., Mlambo M., Marquet G. & Tiberghien, P., February 16, 2018; MNHN-IU- 2018-67, 1♀ ovig. cl 6.8mm and MNHN-IU- 2018-68, 1♀ ovig. cl 7.0mm, River iLovu, altitude 8m, 17��05.858'S 30��49.390'E, coll. Maliwa L., Mlambo M., Marquet G. & Tiberghien, P., February 17, 2018. MAYOTTE. MNHN-IU- 2018-69, 1♀ ovig cl 6.1mm, River Bouyoni, altitude 14m, 12��43.966'S 45��8.250'E, coll. ARDA, May 15, 2006; MNHN-IU- 2018-70, 1♀ cl 4.5mm and MNHN-IU- 2018-71, 1♀ cl 6.0mm, River Dembeni, altitude 19m, 12��50.402'S 45��10.461'E, coll. ARDA, November 12, 2003; MNHN-IU- 2018-72, River Kwal��, altitude 39m, 12��48'092'S 45��11.520'E, coll. ARDA, November 10, 2003; MNHN-IU- 2018-73, 1♀ cl 4.6mm, MNHN-IU- 2018-74, MNHN-IU- 2018-76 and MNHN-IU- 2018-75, 1♀ cl 5.2mm, River Soulou, altitude 14m, 12��45.812'S 45��5.951'E, coll. ARDA, November 9, 2003. COMOROS. MNHN-IU- 2018- 77, 1♀ ovig. cl 3.8mm (DNA: CA1344), River Bwanifunge, Moheli Island, altitude 39m, 12��19.642'S, 43��40.240'E, coll. A. Abdou December 30, 2013; MNHN-IU- 2018-78, 1♀ ovig. cl 4.5mm (DNA: CA1343), River Mdjawashe, Moheli Island altitude 18m, 12��21.386'S, 43��41.944'E, coll. A. Abdou, December 31, 2013. MADAGASCAR. MNHN-IU- 2018-79, 1♀ ovig. cl 4.1mm (DNA: CA1035), MNHN-IU- 2018-80, 1♀ ovig. 4.8mm (DNA: CA1037), MNHN-IU- 2018-81, 1♀ cl 4.3mm and MNHN-IU- 2018-82, 1♂ cl 4.8mm, River Ambodiforaha, altitude 9m, 15��43.054'S 49��57.637'E, coll. R. Fara, H. Grondin, G. Marquet, T. Robinet, May 15, 2010; MNHN-IU- 2018-87, 1♀ ovig cl 3.5mm, MNHN-IU- 2018-83, 1♀ ovig cl 5.2mm, MNHN-IU- 2018-88 1♀ cl 4.0mm, MNHN-IU- 2018-85, 1♀ cl 4.0mm, MNHN-IU- 2018-86, 1♀ cl 4.3mm and MNHN-IU- 2018-84, 1♂ cl 4.0mm, River Andempona, Ampanasanovy estuary, altitude 0m, 14��35.298'S 50��10.105'E, coll. C. Ellien, R. Fara, E. Feunteun, N. Mary, T. Robinet, July 0 4, 2008; MNHN-IU- 2018-89, 1♀ ovig. cl 4.7mm, MNHN-IU- 2018-90, 1♀ cl 4.7mm, MNHN-IU- 2018-92, 1♀ cl 4.9mm, MNHN-IU- 2018-91, 1♀ cl 5.5mm, MNHN-IU- 2018-93, 1♂ cl 3.8mm and MNHN-IU- 2018-94, 1♂ cl 4.0mm, River Ankavia, altitude 23m, 14��59.488'S 50��11.095'E, coll. C. Ellien, R. Fara, E. Feunteun, N. Mary, T. Robinet, July 0 3, 2008; MNHN-IU- 2018-95, 1♀ ovig. cl 4.0mm, MNHN- IU- 2018-96, 1 ♀ cl 4.8mm, MNHN-IU- 2018-97, 1♀ cl 5.5mm and MNHN-IU- 2018-98, 1♂ cl 3.0mm, River Fanambana, altitude 11m, 14��33.517'S 50��10.017'E, coll. C. Ellien, R. Fara, E. Feunteun, N. Mary, T. Robinet, July 4, 2008; MNHN-IU- 2018-99, 1♀ ovig cl 3.9mm (DNA: CA1184) and MNHN-IU-2018-100, 1♀ cl 4.8mm (DNA: CA1185), unknown locality, coll. C. Ellien, R. Fara, E. Feunteun, N. Mary, T. Robinet. SEYCHELLES ISLANDS. MNHN-IU-2017-1445, 1♀ ovig. cl 4.8mm (DNA: CA1195) and MNHN-IU-2017-1446, 1♀ cl 4.8mm (DNA: CA1194), unknown river, Mah�� Island, coll. ARDA, November 24, 2004; MNHN-IU-2017-1447, 1♀ ovig. cl 4.5mm (DNA: CA1186) and MNHN-IU-2017-1448, 1♂ cl 4mm (DNA: CA1187), River Nouvelle D��couverte, Praslin Island, altitude 8m, 4��19.304'S 55��42.351'E, coll. ARDA, October 0 8, 2003.; MNHN-IU-2017-1449, 1♀ ovig. cl 4.9mm (DNA: CA1197) and MNHN-IU-2017-1450, 1♂ cl 4.1mm (DNA: CA1196), River Grande Barbe, Silhouette Island, 4��30.052'S 55��13.537'E, coll. ARDA, November 20, 2004. MAURITIUS. MNHN-IU-2017- 1451, 1♀ ovig. cl 4.2mm, MNHN-IU-2017-1452, 1 juvenile cl 2.3mm, MNHN-IU-2017-1454, 1 juvenile cl 2.4mm and MNHN-IU-2017-1453, 1 juvenile cl 2.6mm; Forested lake, saline, near Camp Poorun, altitude 11m, 20��10.517'S 57��45.767'E, coll. C. R. Turner, December 11, 2005. Diagnosis. Carapace (Fig. 2m, n, o) smooth, glabrous, with sharp antennal spine placed at lower orbital angle. Pterygostomian margin rounded. Rostrum rather constantly long, 0.8���1.3 of cl, straight or curved up distally, reaching well beyond scaphocerite. 15���26 dorsal teeth, leaving distally unarmed part of rostrum 0.4���1.2 times that of armed part, except for one to three subapical tooth, 1 to 2 post-orbital teeth present. 7���23 teeth present on the ventral margin extending from highest part of the rostrum either to tip or with short distal part unarmed. Number of dorsal teeth on the rostrum before the most proximal ventral tooth 10���14. Rostral formula: (1���2) 15���26 + 1���3 / 7��� 23. First pereiopod (Fig. 2a): Stout, chela about 1.8���2.4 times as long as wide, dactylus 2.5���6.0 times as long as wide, 0.8���1.6 length of palm; carpus 1.7���3.3 times as long as wide with shallow excavation on anterior margin. Second pereiopod (Fig. 2b): More slender and longer than first pereiopod. Chela 1.9���3.0 times as long as wide, dactylus 3.5���7.0 times as long as wide, 1.1���1.9 times length of palm; carpus 4.3���6.0 times as long as wide. Third pereiopod (Fig. 2c): Dactylus (Fig. 2d): 2.9���4.0 times as long as wide (terminal spine included) with 6���9 spineson flexor margin in addition to the terminal one; propodus 12.7���18.6 times as long as wide, 4.1���6.6 times as long as dactylus. Fifth pereiopod (Fig. 2e): Dactylus (Fig. 2f): 3.0���6.01 times as long as wide with 31���61 spiniform setae on flexor margin; propodus 15.2���22.0 times as long as wide, 4.3���5.7 as long as dactylus. First male pleopod (Fig. 2k): Endopod leaf-like with a developped appendix interna in males. Second male pleopod (Fig. 2l): Appendix masculina on second pleopod reaching 0.52 times length of endopod; appendix interna reaching about 0.84 times length of appendix masculina. Egg size (Fig. 2j): 0.35���0.46 �� 0.22���0.29 mm. Preanal carina (Fig. 2h): with a strong spine. Telson (Fig. 2i): ending triangular with a posteromedian projection; 1 pair of longer lateral simple setae and 2 to 3 pairs of shorter intermediate simple setae shorter or slightly longer. Uropodal diaeresis (Fig. 2g): with 9���14 short spinules. Colour pattern. Colours (Fig. 3) vary and tend to match the substrate the shrimp lives on. The body can vary from hyaline to brownish with red dots, with sometimes a large red border on the ventral side of the rostrum. An oblique brown or carmine red band on the cephalothorax is very characteristic. The coloration is lost on preserved animals. Habitat. All specimens were collected in the lower course of rivers, (altitude 5���25 m), among macrophytes in running water. Distribution. C. natalensis occurs in Comoros (Anjouan, Moh��li), Mayotte, Seychelles (La Digue, Mah��, Praslin and Silhouette), Mauritius, in Madagascar and South Africa. Present before in Reunion Island (Costa 1980; Kiener & Duchochois 1981) this species seems now absent despite extensive propspections made there since (Fig. 4)., Published as part of Mazancourt, Valentin De, Castelin, Magalie, Renneville, Clementine, Mlambo, Musa C., Marquet, Gerard & Keith, Philippe, 2019, Revalidation of Caridina natalensis De Man, 1908 (Crustacea: Decapoda: Atyidae) in the South Western Indian Ocean, pp. 375-387 in Zootaxa 4543 (3) on pages 379-384, DOI: 10.11646/zootaxa.4543.3.3, http://zenodo.org/record/2617875, {"references":["De Man, J. G. (1908) On Caridina nilotica and its varieties. Records of the Indian Museum, 2, 255 - 283.","Lenz, H. (1912) Afrikanische Crustaceen aus schwedischen sammlungen. Arkiv fur Zoologi, 7 (29), 1 - 10.","Bouvier, E. L. (1925) Recherches sur la morphologie, les variations, la distribution geographique des crevettes de la famille des Atyidae. Encyclopedie entomologique, 4, 1 - 370.","Barnard, K. H. (1950) Descriptive Catalogue of South African Decapod Crustacea. Annals of the South African Museum, 38, 1 - 864.","Richters, F. (1880) Betrage zur Meeresfauna der Insel Mauritius und der Seychellen. Decapoda, 162 - 163.","Holthuis, L. B. (1965) The Atyidae of Madagascar. Memoires du Museum National d'Histoire Naturelle, Series A, Zoologie, 33 (1), 1 - 48.","Keith, P., Marquet, G., Valade, P., Bosc, P. & Vigneux, E. (2006) Atlas des poissons et des crustaces d'eau douce des Comores, Mascareignes et Seychelles. Museum national d'Histoire naturelle, Patrimoines naturels, 65, 1 - 250.","Lenz, H. (1910) Crustaceen von Madagaskar, Ostafrika and Ceylon. In: Voeltzkow, A. (Ed.), Reise in Ostafrika in den Jahren 1903 - 1905 mit Mitteln der Hermann und Elise geb. Heckmann Wentzel-Stiftung ausgefuhrt, 2, pp. 539 - 576.","Roux, J. (1929) Crustacea. III. Atyidae. In G. Petit, Contribution a l'etude de la faune de Madagascar. Faune des colonies francaises, 3, 293 - 319.","Costa, H. H. (1980) Results of the Austrian-Indian Hydrobiological Mission 1974 to the Seychelles-, Comores and Mascarene- Archipelagos: Part III: The Ecology and the Distribution of Decapoda Caridea in the Indian Ocean Islands of Seychelles, Mauritius, Comores & Reunion. Annalen des Naturhistorischen Museums in Wien, 83, 673 - 700.","Richard, J. & Clark, P. F. (2010) Caridina H. Milne Edwards, 1837 (Crustacea: Decapoda: Caridea: Atyoidea: Atyidae) freshwater shrimps from eastern and southern Africa. Zootaxa, 2372, 305 - 337.","Roux, J. (1920) Susswasserdekapoden von den Aru- und Kei-Inseln. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 35, 317 - 351.","Kiener, A. & Duchochois, P. (1981) Etude des problemes piscicoles des eaux interieures de la Reunion. CEMAGREF. Report. Section Qualite des eaux de peche et pisciculture, Study n ° 25, Aix en Provence, 140 pp"]}

Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.