Caridina sodenensis, 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 : 42-45

Caridina sodenensis sp. nov.

( Figs. 20 , 21 )

Material examined. Holotype: ♂ Cameroon Lake Soden, West Cameroons, 28.10.63, coll. & pres. Dr. C. A. Wright, NHM 2007.712. Paratypes: 76♂, 9♀, ovig., 5♀, 209 juv. Lake Soden, West Cameroons, 28.10.63, coll. & pres. Dr. C. A. Wright, NHM 2007.713–721.

Description. Total length: 10–20 mm. Carapace length: 2.5–3.5 mm.

Rostrum ( Fig. 20a, b, c, d ): equal to middle of third segment of antennular peduncle or shorter. 2–2.5mm in length. 0.6–0.7 × long as carapace. 18–30 (mostly 22–28) teeth on dorsal margin arranged to tip. 1–4 (mostly 2–3) post-orbital teeth. 1–10 teeth on ventral margin arranged to tip or with short unarmed distal end ( Fig. 20c ). Tip pointed. Formula (1–4) 18–30/1–10 mostly (2–3) 22–30/1–7.

Antennular peduncle ( Fig. 20e ): 0.65–0.75 × carapace. Stylocerite 0.6–0.7 × length of basal segment. Anterolateral teeth of basal segment 0.2–0.3 × second segment. 9–12 segments bearing aesthetascs.

First pereiopod ( Fig. 21a ): dactylus 1.3–1.5 × palm of propodus. Chela 3.1–3.5 × long as broad. Carpus 2.6–3.1 × long as broad, anterior end almost flat.

Second pereiopod ( Fig. 21b ): dactylus1.4–1.7 × long as palm of propodus. Chela 3.1–3.5 × long as broad. Carpus 5.5–6 × long as broad.

Third pereiopod ( Fig. 21c, d ): dactylus 2.7–3.1 × long as broad. Spines on dactylus varied from 5–9 (including terminal spines), mostly 5–7. Propodus 4.5–5 × long as dactylus and 11–12 × long as broad with 7–12 spines arranged along posterior margin. Carpus 0.6–0.7 × long as propodus, with minute spines on inner margin. Merus 1.9–2.3 × carpus length. Merus with 3 large spines on posterior margin.

Fifth pereiopod ( Fig. 21e, f ): dactylus 4–4.5 × long as broad with 25–45 spines arranged in comb-like fashion on inner margin. Propodus 12–13 × long as broad and 3.5–4.2 × long as dactylus with 9–12 spines arranged along inner margin. Carpus 0.5–0.7 × propodus length and with minute spines along inner margin. Merus 1.5–1.75 × carpus length, with 2 spines and several fine setae at posterior margin.

Setobranchs: 1 on all pereiopods.

First male pleopod ( Fig. 21g, h ): endopod longer being 0.45–0.55 × exopod length. Appendix interna absent. Long setae are uniformly arranged along entire margin of endopod

First female pleopod ( Fig. 21i ): endopod 0.50–0.6.5 × long as exopod.

Eggs ( Fig. 21j ): 55–65, 0.45–0.55 × 0.27–0.35 mm in size.

Second male pleopod ( Fig. 21k, l, m ): appendix masculina 0.9–1.1 × appendix interna. 0.2–0.25 × endopod.

Sixth abdominal somite carapace: 0.75–0.85 × long as carapace.

Telson ( Fig. 21n, o ): 0.75–1.1 × long as sixth abdominal segment. Dorsal spines 3–4 pairs (including sub terminal spine). 1 pair of plain lateral spines and 2–4 pairs of stalked plumose process present at posterior margin.

Uropod ( Fig. 21p, q ): 4–8 (mostly 4–5) diaeresis spinules.

Preanal carina ( Fig. 21r ): Unarmed.

Remarks. Caridina sodenensis sp. nov. is distinct with a short rostrum reaching the middle of the third segment of the antennular peduncle or shorter. The rostrum has 18–30 teeth on dorsal margin, always arranged to the tip with 1–10 teeth on ventral margin. The tip of the rostrum is always pointed. The endopod on the first pleopod of male is longer. The appendix masculina is short and is shorter, equal to or longer than the appendix interna. The number of eggs is 55–65 of 0.45–0.55 × 0.27–0.35 mm size. Fewer spinules on the uropod diaeresis. These characters distinguish the species from C. africana and C. togoensis .

Caridina sodenensis sp. nov. is closer to C. ghanensis in possessing a short appendix masculina which is shorter, equal to, or slightly longer than the appendix interna. However, C. sodenensis sp. nov. differs from C. ghanensis in having a shorter rostrum with 18–30 teeth on the dorsal margin of the rostrum to the pointed tip, a longer endopod on the first male pleopod and 55–65 smaller sized eggs.

Etymology. Named sodenensis , after Lake Soden, Cameroons, the type locality.

Figures

FIGURE 20. Caridina sodenensis sp. nov., NHM 2007.713–721, ♂1: a) Entire; b) Rostrum enlarged. ♂2: c) Anterior region of cephalothorax. ♂3: d) Anterior region of cephalothorax. ♂1: e) Antennular peduncle.

FIGURE 21. Caridina sodenensis sp. nov., NHM 2007.713–721, ♂: 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) Appendix masculina; n) Telson; o) Posterior margin of telson; p) Uropod; q) Uropod diaeresis spinules; r) Preanal carina.