Caridina natalensis De Man, 1908

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, Zootaxa 4543 (3), pp. 375-387 : 379-384

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 Kwalé , 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, Mahé 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 Découverte , 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, Mohéli), Mayotte, Seychelles (La Digue, Mahé, 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 ).

Figures

FIGURE 2. Caridina natalensis; a. first pereiopod; b. second pereiopod; c. third pereiopod; d. fifth pereiopod; e. dactylus of fifth pereiopod; f. dactylus of third pereiopod; g. uropodal diaeresis; h. pre-anal carina; i. telson; j. eggs; k. second male pleopod; l. first male pleopod; m. anterior region of cephalothorax: n, o. rostrum variations.

FIGURE 3. a, b, c, d: Views of living specimens of Caridina natalensis showing their coloration; a. Specimen from Madagascar (G. Marquet); b. Specimen from Seychelles (P. Keith); c, d. Specimen from South Africa (G. Marquet). e: Example of habitat where C. natalensis lives; Iharaka river, Madagascar (G. Marquet).

FIGURE 4. Distribution of Caridina natalensis with sampling localities of the specimens of this species examined for the study (black circles) and its type locality (white star).