Caridina liaoi, Cai & Choy & Ng, 2009

Cai, Yixiong, Choy, Satish & Ng, Peter K. L., 2009, Epigean And Hypogean Freshwater Shrimps Of Bohol Island, Central Philippines (Crustacea: Decapoda: Caridea), Raffles Bulletin of Zoology 57 (1), pp. 65-89 : 72-75

Caridina liaoi , new species

( Figs. 5 , 6 )

Material examined. – Holotype: Ovigerous female, cl 4.1 mm, USC, Bilar River, Bilar, coll. Y. Cai et al., 19 Dec.2000.

Paratypes: 82 males, cl 2.8–4.3 mm, 112 females, cl 3.7–5.0 mm, 26 ovigerous females, cl 4.2–5.0 mm, ZRC 2007.0284 , data same as holotype .

Description. – Rostrum ( Figs. 5A , 6A ) long, reaching near to or slightly beyond end of scaphocerite; rostral formula: 3–4+13–14/13–15. Antennal spine fused with inferior orbital angle. Pterygostomian margin broadly rounded.

Sixth abdominal somite 0.51 times of carapace, 1.7 times as long as fifth somite, distinctly shorter than telson. Telson ( Figs. 6B, C ) 3.5 times as long as wide, not terminating in a projection, with 3 or 4 pairs of dorsal spinules and 1 pair of dorsolateral spinules; lateral pair of spines distinctly longer than intermediate pairs of spiniform setae. Preanal carina ( Fig. 6K ) high, triangular, lacking spine.

Eyes well developed, anterior end reaching to 0.8 times length of basal segment of antennular peduncle. Antennular peduncle 0.74 times as long as carapace; basal segment of antennular peduncle longer than both second and third segment lengths, anterolateral angle reaching 0.20 times length of second segment, second segment distinctly longer than third segment. Stylocerite reaching to 0.8 times length of basal segment of antennular peduncle. Scaphocerite ( Fig. 6D ) 3.4 times as long as wide.

Incisor process of mandible ending in irregular teeth, molar process truncated. Lower lacinia of maxillula broadly rounded, upper lacinia elongated, with a number of distinct teeth on inner margin, palp slender. Upper endites of maxilla subdivided, palp short, scaphognathite tapering posteriorly with some long, curved setae at posterior end. Palp of first maxilliped broadly triangular. Second maxilliped typical of genus. Third maxilliped reaching to end of antennular peduncle, with ultimate segment as long as penultimate segment.

Epipods on first 4 pereiopods. First pereiopod ( Figs. 5B , 6E ) reaching to end of basal segment of antennular peduncle; merus 1.9–2.2 times as long as broad, shorter than carpus; carpus excavated anteriorly, shorter than chela, 1.3–1.7 times as long as high; chela 2.3–3.5 time as long as broad; fingers slightly shorter, as long as or distinctly longer than palm. Second pereiopod ( Figs. 5C , 6F ) reaching to end of second segment of antennular peduncle; merus as long as carpus, 4.2–5.0 times as long as broad; carpus 1.1 times as long as chela, 2.3–2.4 times as long as high; chela 2.3–2.4 times as long as broad; fingers 1.6 times as long as palm. Third pereiopod ( Figs. 5D, E , 6G, H ) reaching to end of antennular peduncle, propodus 11–12 times as long as broad, 4.5–4.7 times as long as dactylus; dactylus 3.1–3.3 times as long as wide (spines included), with 4–6 accessory spines on flexor margin. Fifth pereiopod reaching to end of second segment of antennular peduncle, propodus 14–18 times as long as broad, 3.6–3.8 times as long as dactylus, dactylus 4.0–4.4 times as long as wide (spinules included), terminating in 1 large claw, with 60–65 spinules on flexor margin.

Endopod of male first pleopod ( Fig. 5H ) sub-rectangular, two-fifth length of exopod, no appendix interna. Appendix masculina of male second pleopod ( Fig. 5I ) half length of endopod, with appendix interna reaching near end of appendix masculina.

Uropodal diaeresis ( Fig. 6L ) with 14–16 movable spinules.

Ovigerous females with eggs sized 0.92–0.95 × 0.55–0.60 mm.

Habitat. – Caridina liaoi , new species, was collected from a tributary of the Bilar River near Bilar town, Bohol Island in central Philippines.

Etymology. – The new species is named after Dr. Lawrence Liao, who has been instrumental in helping the first author making collections in the Philippines for the present study.

Remarks.- Caridina liaoi , new species, is similar to C. buhi Cai & Shokita, 2006a , from Luzon, by the form of pereiopods, but it differs from C. buhi by its longer rostrum (reaches to or slightly beyond the anterior margin of the scaphocerite vs. reaches to the end of the second segment of the antennular peduncle or to the end of the antennular peduncle); the more ventral rostral teeth (13–15 vs. 3–7); the telson does not terminate in a projection vs. terminate in a projection; the bigger appendix interna on the male second pleopod (reaches near the end of the appendix masculina vs. reaches the base of the distal two-third length of the appendix masculina) and the distal spines on the telson (lateral spines much longer than the intermediate pairs of spiniform setae vs. lateral spines subequal to intermediate pairs) ( Figs. 5 , 6 ; cf. Cai & Shokita, 2006a: Figs. 3 , 4 ).

Figures

Fig. 5. Caridina liaoi, new species. A: cephalothorax and cephalic appendages, lateral view; B, first pereiopod; C, second pereiopod; D, third pereiopod; E, dactylus of third pereiopod; F, fifth pereiopod; G, dactylus of fifth pereiopod; H, endopod of male first pleopod; I, appendix masculina and appendix interna of male second pleopod. Scale bars: A–D, F = 1 mm; E, G = 0.1 mm; H, I = 0.2 mm (male, cl 4.0 mm, paratype, ZRC, Bilar river).

Fig. 6. Caridina liaoi, new species, A: cephalothorax and cephalic appendages, lateral view; B, distal portion of telson; C, telson; D, scaphocerite; E, first pereiopod; F, second pereiopod; G, third pereiopod; H, dactylus of third pereiopod; I, fifth pereiopod; J, dactylus of fifth pereiopod; K, preanal carina; L, uropodal diaeresis. Scales: A, C–G, I = 1 mm; B, L = 0.2 mm; H, J = 0.1 mm; K = 0.5 mm. (ovig. females, cl 4.6 mm, paratype, ZRC, Bilar River).

Fig. 3. Caridina lobocensis, new species: A, cephalothorax and cephalic appendages, lateral view; B, distal portion of telson; C, first pereiopod; D, second pereiopod; E, third pereiopod; F, dactylus of third pereiopod; G, fifth pereiopod; H, dactylus of fifth pereiopod; I, preanal carina; J, uropodal diaeresis. Scale bars: A = 2 mm, B, F, H, J = 0.2 mm; C–E, G = 1 mm; I = 0.5 mm (male, cl 5.7 mm, paratype, ZRC, Bohol Island, Philippines).

Fig. 4. Caridina lobocensis, new species: A, telson; B, endopod of male first pleopod; C, appendix masculina and appendix interna of male second pleopod; D, first pereiopod; E, second pereiopod; F, third pereiopod; G, dactylus of third pereiopod; H, fifth pereiopod; I, dactylus of fifth pereiopod. Scale bars: A, D–F, H = 1 mm; B, C, G, I = 0.2 mm (A–C, male, cl 5.7 mm, paratype, ZRC, Bohol Island, Philippines; D–I, female, cl 6.9 mm, paratype, ZRC, Bohol Island, Philippines).