Caridina angulata Bouvier, 1905

Richard, Jasmine & Clark, Paul F., 2010, Caridina H. Milne Edwards, 1837 (Crustacea: Decapoda: Caridea: Atyoidea: Atyidae) - freshwater shrimps from eastern and southern Africa *, Zootaxa 2372 (1), pp. 305-337 : 313-316

publication ID	https://doi.org/ 10.11646/zootaxa.2372.1.24
persistent identifier	https://treatment.plazi.org/id/03AC8791-8608-FF81-FF6E-F9FFFB67FE22
treatment provided by	Felipe
scientific name	Caridina angulata Bouvier, 1905
status

Treatment

Caridina angulata Bouvier, 1905 View in CoL

( Figs. 5–6 View FIGURE 5 View FIGURE 6 )

Caridina angulata Bouvier 1905: 75 View in CoL (key), 84, fig. 8; 1912: 919;1913: 465; 1925: 240 (partim), figs. 555, 558–561. — Lenz 1910: 570.

Nec Caridina angulata Bouvier 1925: 240 View in CoL (partim), figs. 556–557 = undescribed or another Caridina species.

Material examined. Types: Caridina angulata : female holotype, Madagascar Ranofotsy, near Fianarantosa, coll. Ch. Allaud 1901, MNHN Na 666 .

Non-types: Madagascar stn 162, Vayssie, coll. 1917, MNHN Na 667 1 male, 1 female; C80, Andranoloha and Tongoroby, Onilohy River , Belsioky District, coll. Hon. P.A. Mathuen, det. Bouvier 1918, NHM 1920.1.23.1–3, 1 ov. female . Kenya Belazoni, pres. Hugh Copley, det. J. Richard & P. Clark, NHM 1955.1.24.18; 1 ov. female; Sabaki River , pres. Hugh Copley, det. J. Richard & P. Clark, NHM 1955.1.24.19.21, 3 ov. females .

Description. Total length: 24–35 mm. Carapace length: 7–8 mm.

Rostrum ( Figs. 5a–e View FIGURE 5 ): extending from 2 nd segment of antennular peduncle to end. Length 3–5 mm, 0.4–0.6 as long as carapace with 14–20 teeth proximally on dorsal margin leaving 0.3–0.5 of length unarmed. 0 or 1 post-orbital teeth. 5–10 teeth arranged on ventral margin either up to tip or leaving short distal part unarmed. Formula (0–1) 14–20/5–10. Tip always pointed.

Antennular peduncle ( Fig. 5f View FIGURE 5 ): stylocerite 0.6–0.8 as long as basal segment, anterolateral teeth of basal segment 0.15–0.25 as long as second segment, 18–22 segments bearing aesthetascs.

First pereiopod ( Fig. 6a View FIGURE 6 ): dactylus 1.5–1.6 as long as palm of propodus. Chela 2.3–2.5 as long as wide. Carpus 1.3–1.4 as long as wide with deep anterior excavation.

Second pereiopod ( Fig. 6b View FIGURE 6 ): dactylus 1.9–2 as long as propodus. Chela 2.8–2.9 as long as wide. Carpus, 3–3.5 as long as wide.

Third pereiopod ( Figs. 6c–d View FIGURE 6 ): dactylus 2.8–3 as long as wide. Spines on dactylus varing from 5–7 (including terminal spines). Propodus 4.0–4.7 as long as dactylus and 9–10 as long as wide with 15–16 spines closely set along inner margin. Carpus 0.6–0.7 as long as propodus with spines on inner margin. Merus 2.0– 2.2 of carpus length. Merus with 4 large spines on posterior margin.

Fifth pereiopod ( Figs. 6e–f View FIGURE 6 ): dactylus 2.0–2.2 as long as wide with 45–60 spines in comb-like arrangement on inner margin. Propodus 9–10 as long as wide and 4–5 as long as dactylus with 10–15 spines along inner margin. Spine at the anterior end of propodus characteristically long, almost reaching 0.25–0.5 of dactylus. Carpus 0.5–0.6 of propodus length and with minute spines along inner margin. Merus 1.5–1.9 of carpus length, with 1 large and 1 small spine along inner margin.

Setobranch: comprising of 4 setae on each pereiopod.

First male pleopod ( Figs. 6g –h View FIGURE 6 ): endopod 0.38 of exopod length. Appendix interna present and located within inward curvature of tip of endopod. Dense setae present on outer margin and few short setae on inner margin.

First female pleopod ( Fig. 6i View FIGURE 6 ): endopod 0.5–0.6 as long as exopod.

Eggs ( Fig. 6j View FIGURE 6 ): ca. 1300, 0.35–0.39 × 0.20–0.23 mm in size.

Second male pleopod ( Figs. 6k–l View FIGURE 6 ): appendix masculina 1.8 as long as appendix interna and 0.36 times exopod.

Sixth abdominal somite: 0.4–0.5 as long as carapace.

Telson ( Figs. 6m –n View FIGURE 6 ): tapering distally and 1.0–1.2 as long as 6 th abdominal somite. 6–7 pairs (including subterminal spine) of dorsal spines present. Posterior margin triangular with 1 pair of short lateral spines and 3 pairs or 7 short stalked sparsely plumose processes.

Uropod ( Fig. 6o View FIGURE 6 ): 19–21 diaeresis spinules.

Preanal carina ( Fig. 6p View FIGURE 6 ): sharp with small spine.

Distribution. Kenya, Madagascar.

Remarks. Bouvier (1905) listed the diagnostic characters of C. angulata and this species can be identified by the distinct arrangement of teeth on the dorsal rostral margin proximally leaving the distal part always unarmed, the postorbital teeth may or may not be present, teeth on the ventral margin arranged either up to the tip or with a short unarmed distal margin, tip of the rostrum always pointed, propodus of the fifth pereiopod with a characteristically elongated spine at the anterior margin being 0.25–0.5 of the dactylus, first pleopod of male with the unique inwardly curved tip of the endopod holding a short appendix interna, telson with triangular posterior margin bearing short stalked spines 19–21 uropod diaeresis spinules and ca. 1300 eggs of 0.35–0.39 × 0.2–0.23 mm in size.

Two of the 3 ovigerous females ( Bouvier, 1925, figs. 556, 557) from Madagascar, NHM 1920.1.23.1–3, differ from the type specimens in having an unarmed dorsal margin and in bearing 4 minute spines at the centre of the dorsal margin of the rostrum. These 2 ovigerous females are not considered to be C. angulata and consequently are not included in this description. Further examination of additional material will be required to ascertain if they are new species .

While describing the Atyidae of Madagascar, Holthuis (1965) listed C. angulata and considered that either it could be a subspecies of C. calmani Bouvier, 1919 or both might be the same species. In the present study, type specimens of C. calmani (syntype Madagascar, coll. Methuen. MNHN Na 676 1 male; cotypes, Ambatornharanana, Mount leading to Mangaro Terrace, coll. Hon. P. A. Methuen, det. Bouvier, NHM 1920.1.23.4–5; 1 male, 1 female) were examined. Caridina angulata differs from C. calmani in having a longer rostrum, teeth only proximally on the dorsal margin of the rostrum leaving the distal margin unarmed, presence of a long spine at the anterior end of the propodus of the fifth pereiopod, characteristically shaped appendix interna on the first pleopod of male, ca. 1300 minute eggs and in possessing short stalked sparsely plumose spines at the triangular posterior margin of the telson. Caridina angulata and C. calmani are distinct species. The occurrence of C. angulata from Kenya is the first report of the species on mainland Africa.