Caridina belazoniensis, 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 : 33-35

Caridina belazoniensis sp. nov.

( Figs. 14 , 15 )

Material examined. Holotype: ♀ ovig. Kenya Mbelazoni, Lower Athi River, Sabaki Estuary, coll. & pres. Hugh Copley, 1954, NHM 2007. 723. Paratypes: Kenya Belazoni, Pres. Hugh Copley, NHM 1955.1 24.22–26, 4♂, 14♀ ovig., 4♀; Mbelazoni, Lower Athi River, Sabaki Estuary, coll. & pres. Hugh Copley, 1954, NHM 2007.702–711, 1♂, 26♀ ovig., 4♀. South Africa Kwazulu Natal, Usutu River, Dirt Road, Near bridge, Usutu River System, Matata, 26° 51' 22"S, 31° 54' 31"E, R. Bills, 31.3.2003, AM GEN 1758 A, 1♂, 2♀ ovig.

Description. Total length: 25–38 mm. Carapace length: 4.5–6 mm.

Rostrum ( Fig. 14a, b, c ): always longer than antennal scale. 4.5–7.5 mm in length. 1–1.2 × long as carapace. 5–20 (mostly 12–15) teeth on dorsal margin leaving 0.5–0.55 of length distally unarmed. No post-orbital teeth. 14–25 (mostly 17–21) teeth on ventral margin leaving short distal end unarmed. Tip usually bifid, rarely pointed. Formula (0) 5–20/14–25, mostly (0) 12–15/17–21.

Antennular peduncle ( Fig. 14d ): 0.6–0.75 × carapace. Stylocerite 0.6–0.8 × length of basal segment. Anterolateral teeth of basal segment 0.2–0.3 × second segment. 12–15 segments bearing aesthetascs.

First pereiopod ( Fig. 15a ): dactylus 1.5–1.9 × palm of propodus. Chela 2.5–2.9 × long as broad. Carpus 2–2.4 × long as broad, anterior excavation deep.

Second pereiopod ( Fig. 15b ): dactylus 1.5–2.2 × long as palm of propodus. Chela 3.0–3.5 × long as broad; Carpus 3–4 × long as broad.

Third pereiopod ( Fig. 15c, d ): dactylus 2.3–2.9 × long as broad. Spines on dactylus varied from 6–9 (including terminal spines), mostly 7 or 8. Propodus 4.0–5.5 × long as dactylus and 9.5 or 10.5 × long as broad with 20–22 spines arranged along inner margin. Carpus 0.6–0.7 × long as propodus, with minute spines on inner margin. Merus 1.7–2.0 × carpus length. Merus with 2 large spines on the posterior margin.

Fifth pereiopod ( Fig. 15e, f ): dactylus 3.0–3.5 × long as broad with 35–45 spines arranged in comb-like fashion on inner margin. Propodus 13.0–14.5 × long as broad and 4.0–5.3 × long as dactylus with 15–20 spines arranged along inner margin. Carpus 0.5–0.6 × propodus length and with minute spines along inner margin. Merus 1.5–1.8 × carpus length, with 1 large spine on posterior margin.

Setobranchs: 2 on all pereiopods.

First male pleopod ( Fig. 15g, h ): endopod 0.3–0.4 × exopod length. Appendix interna usually turned towards exopod.

First female pleopod ( Fig. 15i ): endopod 0.60–0.75 × long as exopod.

Eggs ( Fig. 15j ): 780–800, 0.35–0.4 × 0.20–0.25 mm in size.

Second pleopod of male ( Fig. 15k, l ): appendix masculina 1.5–1.9 × appendix interna, 0.30–0.35 × endopod.

Sixth abdominal somite: 0.5–0.6 × long as carapace.

Telson ( Fig. 15m, n ): tapering uniformly to blunt posterior margin protruding beyond single pair of plain stout lateral spines. 1.0–1.3 × long as sixth abdominal segment. Dorsal spines 4–6 pairs (including sub terminal spine). 2 or 3 pairs of fine setae may be present on protruding peg-like tip of telson.

Uropod ( Fig. 15o, p ): 7–14 (mostly 9–11) diaeresis spinules.

Preanal carina ( Fig. 15q ): sharp with spine.

Remarks. Caridina belazoniensis sp. nov. is distinguished by the large sized adults with a longer rostrum that always overreaches the antennal scale, absence of the post-orbital teeth, dorsal distal margin of rostrum unarmed and the tip of the rostrum mostly bifid (rarely pointed). The spines on the posterior margin of the telson are limited to a single pair of lateral spines and the posterior margin of the telson protrudes beyond the lateral spines. Females have 780– 800 eggs of 0.35–0.40 × 0.20–0.25 mm size. These characters distinguish C. belazoniensis sp. nov. from C. africana Kingsley (1882) and C. togoensis Hilgendorf (1893)

Etymolgy. Caridina belazoniensis sp. nov. is named after the Belazoni Canal, Kenya, the type locality.

Figures

FIGURE 14. Caridina belazoniensis sp. nov., NHM 1955.1.24.22–26, ♀ ovig.: a) Entire; b) Anterior region of cephalothorax; c) Albany Museum, GEN 1758, anterior region of cephalothorax; d) Antennular peduncle.

FIGURE 15. Caridina belazoniensis sp. nov., NHM 1955.1.24.22–26, ♀ 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.