Caridina ebuneus, Richard & Clark, 2009

Jasmine Richard & Paul F. Clark, 2009, African Caridina (Crustacea: Decapoda: Caridea: Atyidae): redescriptions of C. africana Kingsley, 1882, C. togoensis Hilgendorf, 1893, C. natalensis Bouvier, 1925 and C. roubaudi Bouvier, 1925 with descriptions of 14 new species, Zootaxa 1995, pp. 1-75 : 39-42

Caridina ebuneus sp. nov.

( Figs. 18 , 19 )

Material examined. Holotype: ♀ ovig. Ivory Coast Vicinity Abengourou; 2.1949, coll. B. Holas, pres. Inst. Franç. Afr. Noire., RMNH D 19459. Paratypes: ORSTOM, sta. KAN, det. Corredor, MNHN Na 6161, 11♂, 1♀ ovig., 5♀; 3.1949, coll. B. Holas, pres. Inst. Franç. Afr. Noire., RMNH D 19459, 7♂, 3♀ ovig., 2♀; Gagnoa, 6°04'N 5°55'W, 1954, coll. E. Binder, pres. Mus. Hist. Nat. Genève. RMNH D 11694, 2F; Yapo near Agboville, 10.1946, coll. M. De Keyser, pres. Inst. Franç Afr. Noire, RMNH D 19460, 1♂, 2♀ ovig.

Description. Total length: 20–35 mm. Carapace length: 3.5–4 mm.

Rostrum ( Fig. 18a, b, c ): slightly longer than antennular peduncle or equal to antennal scale, rarely shorter than peduncle. 3–4 mm in length. 0.7–0.9 × long as carapace. 16–24 (mostly 16–20), teeth on dorsal margin leaving 0.3–0.4 of length distally unarmed, unarmed margin occasionally interrupted by 1–2 teeth. 1–3 (usually 2–3) post-orbital teeth. 5–16 (mostly 8–13) teeth on ventral arranged from proximal end almost to tip. Tip bifid or acute. Formula (1–3) 16–24/5–16 mostly (2–3) 16–20/8–13.

Antennular peduncle ( Fig. 18d ): 0.6–0.7 × carapace. Stylocerite 0.7–0.9 × length of basal segment. Anterolateral teeth of basal segment 0.2–0.3 × second segment. 5–7 segments bearing aesthetascs.

First pereiopod ( Fig. 19a ): dactylus 1–1.3 × palm of propodus. Chela 2.1–2.5 × long as broad. Carpus 2–2.5 × long as broad, anterior excavation deep.

Second pereiopod ( Fig. 19b ): dactylus1.1–1.3 × long as palm of propodus. Chela 2–2.5 × long as broad. Carpus 4–5 × long as broad.

Third pereiopod ( Fig. 19c, d ): dactylus 3–3.5 × long as broad. Spines on dactylus varying from 8–12 (including terminal spines), mostly 9–10. Propodus 3.5–4 × long as dactylus and 11–12 × long as broad with 8–12 spines arranged along posterior margin. Carpus 0.55–0.7 × long as propodus, with minute spines on inner margin. Merus 1.9–2.3 × carpus length. Merus with 3 large spines and several fine setae on posterior margin.

Fifth pereiopod ( Fig. 19e, f ): dactylus 5.5–6.5 × long as broad with 60–70 spines arranged in comb-like fashion on inner margin. Propodus 13.0–14.5 × long as broad and 2.5–3.0 × long as dactylus with 10–15 spines arranged along inner margin. Carpus 0.45–0.60 × propodus length and with minute spines along inner margin. Merus 1.4–1.7 × carpus length, with 1 spine at posterior margin.

Setobranchs: 2 on all pereiopods.

First male pleopod ( Fig. 19g, h ): endopod 0.3–0.4 × exopod length. Appendix interna absent.

First female pleopod ( Fig. 19i ): endopod 0.35–0.45 × long as exopod.

Eggs ( Fig. 19j ): 55–60, 0.75–0.9 × 0.4–0.5 mm in size.

Second male pleopod ( Fig. 19k, l ): appendix masculina 1–1.2 × appendix interna. 0.2–0.25 × endopod.

Sixth abdominal somite: 0.70–0.75 × long as carapace.

Telson ( Fig. 19m, n ): 1.0–1.1 × long as sixth abdominal somite. Dorsal spines 3 or 4 pairs (including subterminal spine). 1 pair of plain, short lateral spines and 3 or 4 pairs of stalked plumose process present on posterior margin.

Uropod ( Fig. 19o, p ): 6–10 (mostly 7–8) diaeresis spinules.

Preanal carina ( Fig.19q ): with spine.

Remarks. Caridina ebuneus sp. nov. is similar to C. africana in the arrangement of teeth on the rostrum, arranged from the proximal end of the dorsal margin leaving the distal margin unarmed, with the teeth on the ventral margin of the rostrum arranged from the proximal end of the ventral margin almost to the tip, and with the tip of the rostrum being bifid or pointed. It is different from C. africana in possessing fewer uropod diaeresis spinules and in possessing long plumose processes on the posterior margin of the telson. Caridina ebuneus sp. nov. is similar to C. togoensis in possessing stalked plumose processes on the posterior margin of the telson. However, C. ebuneus differs distinctly from C. togoensis in the arrangement of teeth on the rostrum (with a dorsal distal unarmed margin) with a bifid or pointed tip, teeth on ventral margin of the rostrum always arranged up to the tip, in possessing shorter appendix masculina and in having 50– 60 eggs of comparatively smaller size (0.7–0.9 × 0–0.4– 0.5mm).

Caridina ebuneus sp. nov. is similar to C. ghanensis in possessing a relatively short appendix masculina. However, the appendix masculina is slightly longer than the appendix interna in C. ebuneus sp. nov. while in C. ghanensis , the appendix masculina may be shorter to slightly longer than the appendix interna. Caridina ebuneus sp. nov. differs C. ghanensis in having 5–16 teeth arranged from the proximal end to tip on the ventral margin of rostrum and having 55– 60 eggs.

Etymology. The name, ebuneus , is derived from the Latin for ivory, alluding to the Ivory Coast, where all the material was collected.

Figures

FIGURE 18. Caridina ebuneus sp. nov., MNHN Na 6161, ♀ ovig.: a) Entire. RMNH D 11694, ♀: b) Anterior region of cephalothorax. RMNH D19459, ♀ ovig.: c) Anterior region of cephalothorax; d) Antennular peduncle.

FIGURE 19. Caridina ebuneus sp. nov., MNHN Na 6161, ♀ ovig.: a) First pereiopod, b) Second pereiopod; c) Third pereiopod; d) Dactylus of third pereiopod; e) Fifth pereiopod; f) Dactylus of fifth pereiopod. ♂: g) First pleopod h) Endopod of first pleopod. ♀ ovig.: i) First pleopod; j) Eggs. ♂: k) Second pleopod; l) Appendix masculina; m) Telson; n) Posterior margin of telson; o) Uropod; p) Uropod diaeresis spinules; q) Preanal carina.