Caridina buhi, Shokita, 2006

Shokita, Yixiong Cai Shigemitsu, 2006, Report On A Collection Of Freshwater Shrimps (Crustacea: Decapoda: Caridea) From The Philippines, With Descriptions Of Four New Species, Raffles Bulletin of Zoology 54 (2), pp. 245-270 : 253-256

Caridina buhi , new species

( Figs. 3 , 4 )

Materials examined. – Holotype: ovig. female, cl 4.0 mm, NSMT, Binahugan River , Buhi, Camarines Sur, Luzon, Philippines, 19 Aug.1985.

Paratypes: 1 male, cl 3.3 mm, NSMT , 1 male, cl 3.8 mm, ZRC , 1 ovig. female, cl 4.1 mm, ZRC, 10 males, cl 2.8-3.2 mm, 1 female, cl 3.0 mm, UR, same data as holotype .

Description. – Rostrum ( Figs. 3A , 4A ) straight, reaching near end of second segment of antennular peduncle, or slightly beyond end of antennular peduncle; armed dorsally with 14 to 25, including 3 to 5 (mostly 4-5) posterior to orbital margin, with anterior 1/4 to 1/3 of rostrum length unarmed, armed ventrally with 3 to 7 (mostly 6-7) teeth; antennal spine situated lower than inferior orbital angle. Pterygostomian angle subrectangular.

Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite about 0.6 times as long as carapace, 1.8 times as long as fifth somite, slightly shorter than telson. Telson ( Fig. 3B, C ) 3.0 times as long as wide, terminating in a small projection, with four to five pairs of dorsal spinules and one pair of dorsolateral spinules; lateral pair of distal spines slightly longer than intermediate pairs. Preanal carina small, lacking spine ( Figs. 3J , 4K ).

Eyes well developed. Antennular peduncle 0.6 times as long as carapace; basal segment slightly longer than sum of second and third segment length, anterolateral angle reaching 0.25 times length of the second segment, second segment distinctly longer than third segment. Stylocerite reaching 0.7-0.9 times length of basal segment of antennular peduncle. Scaphocerite ( Fig. 4J ) 3.0 times as long as wide.

Mouthparts similar to that of Caridina cebuensis . Palp of first maxilliped broadly triangular, with a pointed end. Second maxilliped typical. Third maxilliped reaching to end of second segment of antennular peduncle, with ultimate segment as long as penultimate segment.

Epipods on first four pereiopods. First pereiopod ( Figs. 3D , 4B ) reaching to end of basal segment of antennular peduncle; ischium shorter than merus; merus 2.5-3.0 times as long as broad, as long as carpus; carpus excavated anteriorly, shorter than chela, 1.8-1.9 times as long as high; chela 2.3-2.5 times as long as broad; fingers distinctly longer than palm. Second pereiopod ( Fig. 3E, C ) reaching to end of second segment of antennular peduncle; merus shorter than carpus, 4.2-5.2 times as long as broad; carpus 1.1-1.4 times as long as chela, 4.0- 5.5 times as long as high; chela 3.0-3.2 times as long as broad; fingers 1.2-1.3 times as long as palm. Third pereiopod ( Figs. 3F, G , 4D, E ) reaching to end of scaphocerite, ischium shorter than merus; propodus distinctly shorter than merus, 10-12 times as long as broad, 4.5 times as long as dactylus; dactylus 2.5-2.8 times as long as wide (spines included), with 5-6 accessory spines on its flexor margin. Fifth pereiopod ( Figs. 3H, I , 4F, G ) reaching to end of second segment of antennular peduncle, propodus 10-12 times as long as broad, 3.0-3.6 times as long as dactylus; dactylus 3.4-3.8 times as long as broad, with 33-45 spinules on its flexor margin.

Endopod of male first pleopod ( Fig. 4H ) rectangular, half of exopod length, no appendix interna. Appendix masculina of male second pleopod ( Fig. 4I ) 2/3 length of endopod, with appendix interna, slender and small, reaching to 1/4 length of appendix masculina.

Uropodal diaeresis ( Fig. 3k ) with 15-17 movable spinules.

Ovigerous females with egg sized 0.85x 0.50 mm in diameter.

Habitat. – Caridina buhi , new species, was collected from the Binahugan River.

Etymology. – The new species is named after its type locality- Binahugan River in Buhi, Camarines Sur, Luzon. Name used as a noun in apposition.

Remarks. – With respect to the rostrum, and the various pereiopods, Caridina buhi , new species, most resembles C. sumatrensis De Man, 1892 . It could be distinguished from C. sumatrensis by the antennal spine which situated lower than inferior orbital angle (vs. fused with inferior orbital angle in C. sumatrensis ), the preanal carina which is much smaller, the endopod of male first pleopod (does not has appendix interna vs. has in C. sumatrensis ) and the larger egg size (0.85 x 0.50 vs. 0.35 x 0.25 mm). Caridina buhi , new species, is morphologically closest to C. demani Roux, 1911 in the form of rostrum, the male pleopods, but it differs from C. demani by the rostrum having more postorbital teeth (3-5 vs. 2-3) and more ventral teeth (3-7, mostly 6-7 vs. 0-5), the telson which terminates in a small projection (vs. no such projection), and the wider scaphocerite (3.0 times as long as wide vs. 3.7 times).

Distribution. – Philippines.

Figures

Fig. 3. Caridina buhi, new species, ovig. female, cl 4.0 mm, holotype, NSMT, Binahugan River, Buhi, Camarines Sur, Luzon, Philippines: 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, preanal carina; K, uropodal diaeresis. Scale bars: A = 1 mm, B, D-F, H, J = 0.5 mm; C, G, I, K = 0.2 mm.

Fig. 4. Caridina buhi, new species, male, cl 3.3 mm, paratype, ZRC, Binahugan River, Buhi, Camarines Sur, Luzon, Philippines: A, cephalothorax and cephalic appendages; 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, appeedix interna and appendix masculina of male second pereiopod; J, scaphocerite; K, preanal carina. Scale bars: A, J = 1 mm, B-D, F, K = 0.5 mm, E, G, H, I = 0.1 mm.