Shallow water marine gammaridean amphipods of Pulau Tioman, Malaysia, with the description of a new species Author Azman, B. A. R. Author Othman, B. H. R. text ZooKeys 2013 335 1 31 http://dx.doi.org/10.3897/zookeys.335.5567 journal article http://dx.doi.org/10.3897/zookeys.335.5567 1313-2970-335-1 Cymadusa vadosa Imbach, 1967 Figure 4 Cymadusa vadosa Synonymy: Imbach, 1967: 89, pl. 32. Material. 3 specimens, TIO 10, Kampung Tekek, Pulau Tioman, 2 2°49'11"N , 104°9'32"E , washing mix macroalgae, Azman, B.A.R., Josim, J.J., 11 November 1997 ; 4 specimens, TIO 28, Tulai, Pulau Tioman, 2°54'44"N , 104°6'18"E , washing coral rubble, Azman, B.A.R, Kee, A.A., 19 October 2003; 13 specimens, TIO 29, Genting, Pulau Tioman, 2°45'42"N , 104°7'34"E , washing mix macroalgae, Azman, B .A.R., Kee, A.A., 19 October 2003; 5 specimens, TIO 30, Genting, Pulau Tioman, 2°45'42"N , 104°7'34"E , washing mix macroalgae, Azman, B.A.R., Kee, A.A., 20 October 2003. Remarks . The well-developed sharp spur on the peduncle of uropod 1 distinguishes the present specimens from the genera Ampithoe Leach, 1814; Macropisthopous K.H. Barnard, 1916; Amphitholina Ruffo, 1953; Psedopleonexes Conlan, 1982; Pseudoamphitoides Ortiz, 1976; Exampithoe K.H. Barnard, 1926 and Melanesius Ledoyer, 1984. Moreover, the expanded propodus of gnathopod 1 with an oblique palm was found to be a sound character in Peramphithoe Conlan & Bousfield, 1982 used in separating Cymadusa from Peramphitoe (Barnard & Karaman, 1991). Cymadusa differs from Amphithoides Kossmann, 1880 by having narrow rami of uropod 3 and the absence of telsonic lobes. Moreover Paragrubia Chevreux, 1901 differ from Cymadusa by having gnathopod 1 larger than gnathopod 2 and in having a multi-articulate accessory flagellum ( Poore and Lowry 1997 ). Sunamphitoe Bate, 1857 varies from Cymadusa by the absence of a mandibular palp. Barnard and Karaman (1991) have listed fourteen species of Cymadusa , mainly marine and throughout the tropics. Since then another species, Cymadusa munnu (Poore & Lowry, 1997) was described from Port Jackson, New South Wales, Australia. Imbach (1967) illustrated Cymadusa vadosa on the basis of specimens from south-east Asia region, which he identified with Cymadusa filosa (Savigny, 1935), Cymadusa hawaiiensis (Schellenberg, 1938), Cymadusa australis (K.H. Barnard, 1916), Cymadusa sardenta (Oliveira, 1953), Cymadusa brevidactyla (Chevreux, 1908), Cymadusa variata (Sheard, 1936), Cymadusa oceanica (J.L. Barnard, 1955) and Cymadusa crassicornis (Costa, 1853), noting some minor differences between them. Cymadusa vadosa differs from Cymadusa filosa , Cymadusa hawaiiensis , Cymadusa australis , Cymadusa compta , and Cymadusa microphthalma by gnathopod 1 with article 5 shorter than article 6. The Pulau Tioman specimens also appear to be very close to Cymadusa filosa in having; (1) accessory flagellum with 1 articulate; (2) peduncle of uropod 1 with strong, acute, distoventral interramal process; (3) uropod 2 with short triangular inter-ramal process. In all probability, this material from Pulau Tioman is very similar to Imbach's illustrations in having; (1) article 2 of mandibular palp three fourths as long as article 3; (2) maxilliped extends beyond palp article 2; (3) accessory flagellum with 1 articulate; (4) article 5 shorter than article 6 of gnathopod 1; (5) rami of uropod 3 two thirds as long as peduncle; (6) peduncle of uropod 1 with strong, acute, distoventral interramal process; (7) uropod 2 with short triangular interramal process. Figure 4. Cymadusa vadosa Imbach, 1967, female (UKMMZ-1266), 8.8 mm. Kampung Tekek, Pulau Tioman. Scale for A1, G1, G2 represents 0.5 mm; MX1, MX2 scale = 0.25 mm; U1-U3 scale = 0.2 mm.