Macrobrachium equidens, (Dana, 1852)

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 : 86-87

Macrobcrachium equidens ( Dana, 1852)

Palaemon equidens Dana, 1852: 26 [type locality: Singapore].

Palaemon sundaicus – Cowles, 1914: 355, Pl. 2 Fig. 3 (not Palaemon sundaicus Heller, 1862 ).

Macrobrachium equidens – Holthuis, 1950:162, Fig. 36; 1980: 90; Liu et al., 1990: 110, Fig. 8 ; Chace & Bruce, 1993: 25, Fig. 4 ; Yeo et al., 1999: 226; Wowor & Choy, 2001: 282; Cai & Anker, 2004: 389; Cai et al., 2004: 589; Wowor et al., 2004: 349, Fig. 10H ; Short, 2004: 26, Figs. 8 , 9 ; Cai & Shokita, 2006a: 265.

Material examined. – 1 male, cl 7.5 mm, ZRC, River outside Inabacan Cave , Antequrra, coll. Y. Cai et al., 16 Dec.2000 ; 1 male, cl 10.5 mm, 1 female, cl 10.0 mm, ZRC, Loboc River , Loboc, coll. Y. Cai et al., 19 Dec.2000 .

Remarks. – Marcobrachium equidens is a brackish water species, with gravid females and smaller specimens being commonly found in mangrove creeks. It is known from a very wide area in the Indo-West Pacific, from Madagascar to the Solomon Islands and Fiji ( Choy, 1984; Chace & Bruce, 1993; Short, 2004). However, a recent molecular analysis results ( Liu et al., 2007) show that the incongruence of non-monophyly of M. equidens , in 16S, COI and 16S+COI analyses, implied the existence of a cryptic species in the Philippines and Taiwan.

Figures

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. 8. Caridina boholensis, 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, male first pleopod; I, appendix masculina and appendix interna of male second pleopod; J, uropodal diaeresis. Scale bars: A = 1 mm; B–D, F = 0.5 mm; E, G = 0.1 mm; H–J = 0.2 mm (A–C, ovig. females, cl 3.8 mm, paratype, ZRC; D–J, male, cl 3.7 mm, paratype, ZRC, Cave Bongkawi, Antequrra).

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. 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. 9. Caridina valencia, 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, endopod of male first pleopod; J, appendix masculina and appendix interna of male second pleopod; K, uropodal diaeresis. Scale bars: A = 1 mm; B, F, H = 0.1 mm; C–E, G = 0.5 mm; I–K = 0.2 mm. (males, cl 3.4 mm, paratype, ZRC, spring Anislaq, outside Cave Anislaq, Valencia).