Caridina batuan, 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 : 80

Caridina batuan , new species

( Fig. 10 )

Material examined. – Holotype: Ovigerous female, cl 4.2 mm, eggs 0.8 × 0.5 mm, USC, Cave Castigio , Batuan, coll. B. Sket, Feb.1995.

Paratypes: One male, cl 4.1 mm, ZRC 2007.0299 , same data as holotype ; 4 males, cl 2.2–3.7 mm, 5 females, cl 2.5–3.6 mm, 4 juveniles, UOL, Cave Kalumpan , Behind-the-Clouds, Batuan, coll. B. Sket, Feb.1995 ; 1 female, 1 juvenile, UOL, Spring Badyang , cave, Valencia, coll. B. Sket, Feb.1995 ; 2 females, cl 1.9–2.3 mm, ZRC 2007.0300 , Cave Bonugan , Batuan, coll. B. Sket, Feb.1995 ; 2 juveniles, UOL, Alijauan Bridge , stream, S. Duero, coll. B. Sket, 5 Mar.1999 .

Description. – Rostrum ( Fig 10A ) short, reaching slightly beyond end of basal segment of antennular pedunlcle; rostral formula: 0–2+7–12/0–4. Antennal spine distinct, fused with inferior orbital angle. Pterygostomian margin broadly rounded.

Sixth abdominal somite 0.50 times of carapace, 1.9 times as long as fifth somite, slightly shorter than telson. Telson ( Fig. 10B, C ) 2.9 times as long as wide, not terminating in a projection, with 4 or 5 pairs of dorsal spinules and 1 pair of dorsolateral spinules; lateral pair of spines distinctly longer than intermediate pairs. Preanal carina low, sub-triangular, lacking spine.

Eyes reduced, anterior end reaching to 0.4 times length of basal segment of antennular peduncle. Antennular peduncle 0.63 times as long as carapace; basal segment of antennular peduncle shorter 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 0.7 times length of basal segment of antennular peduncle. Scaphocerite 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 rounded. Podobranch of second maxilliped reduced to a lamina. Third maxilliped reaching to end of scaphocerite, with ultimate segment as long as penultimate segment.

Epipods on first 4 pereiopods. First pereiopod ( Fig. 10D ) reaching end of antennular peduncle; merus 2.1 times as long as broad, slightly shorter than carpus; carpus excavated anteriorly, shorter than chela, 1.6 times as long as high; chela 2.1 times as long as broad; fingers slightly shorter than palm. Second pereiopod ( Fig. 10E ) reaching beyond end of scaphocerite by length of chela; merus distinctly shorter than carpus, 4.5 times as long as broad; carpus 1.3 times as long as chela, 5.3 times as long as high; chela 2.6 times as long as broad; fingers 1.3 times as long as palm. Third pereiopod ( Figs. 10F, G ) reaching beyond end of scaphocerite by length of dactylus and half of propodus, propodus 11 times as long as broad, 4.3 times as long as dactylus; dactylus 3.3 times as long as wide (spines included), with 4 or 5 accessory spines on flexor margin. Fifth pereiopod ( Figs. 10H, I ) reaching beyond end of scaphocerite by length of dactylus, propodus 15 times as long as broad, 4.4 times as long as dactylus, dactylus 3.7 times as long as wide (spinules included), terminating in 1 claw, with 44 spinules on flexor margin.

Endopod of male first pleopod sub-triangular, a quarter length of exopod, no appendix interna. Appendix masculina of male second pleopod half length of endopod, with appendix interna half length of appendix masculina, reaching near end of appendix masculina.

Uropodal diaeresis ( Fig. 10J ) with 20 movable spinules.

Ovigerous females with eggs sized 0.80 × 0.50 mm.

Habitat. – Caridina batuan , new species, was collected from several caves in southern part of the Bohol Island, central Philippines.

Etymology. – The new species is named after its type locality- Batuan, Bohol Island, the Philippines. The name is used as a noun in apposition.

Remarks. – Caridina batuan , new species, is morphologically similar to C. minidentata Cai & Anker, 2004 , from west Samar, the Philippines. However, it can be distinguished from C. minidentata by the more developed rostral teeth, the much reduced eyes, the lower preanal carina and the larger number of spinules on diaeresis (20 vs. 16) ( Fig. 10 ; cf. Cai & Anker, 2004: Figs. 4 , 5 ).

Figures

Fig. 10. Caridina batuan, new species: A, cephalothorax and cephalic appendages, lateral view; B, telson; C, distal portion of telson; D, first pereiopod; E, second pereiopod; F, third pereiopod; G, dactylus of third pereiopod; H, fifth pereiopod; I, dactylus of fifth pereiopod; J, uropodal diaeresis. Scale bars: A, B = 1 mm; C = 0.2 mm, D–F, H = 0.5 mm; G, I, J = 0.1 mm (female, cl 3.0 mm, holotype, USC, Cave Kalumpan, Batuan).

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).

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).