Cymadusa Savigny, 1816

Cymadusa Savigny, 1816: 51, 109 [type species: Cymadusa filosa Savigny, 1816, by monotypy].— Barnard & Karaman, 1991: 104.— Poore & Lowry, 1997: 900.

Grubia Czerniavsky, 1868: 103 [type species: Grubia taurica Czerniavsky, 1868, by monotypy]. Acanthogrubia Stout, 1912: 143 [type species: Acanthogrubia uncinata Stout, 1912, by monotypy]. Paradusa Ruffo, 1969: 63 [type species: Paradusa bilobata Ruffo, 1969, original designation].—Barnard & Karaman,

1991: 106.

Diagnosis. Epistome and upper lip directed straight down, 90 degrees to the ventral margin of the head. Antenna 1 accessory flagellum present, 1–3 articulate. Mandible molar well developed; palp 3-articulate. Lower lip outer plate notched. Coxae long. Gnathopod 1 sexually dimorphic, smaller than gnathopod 2, palm acute. Pereopod 3–4 basis narrow; merus not anteriorly expanded. Pereopods 5–7 simple or weakly prehensile. Pereopods 6–7 propodus subrectangular; distal articles slender. Epimeron 3 with or without distoventral tooth. Uropod 1 reaching to the apices of the rami of uropod 2 (in situ); peduncle with long and acute distoventral spur. Uropod 2 peduncle without laterodistal projection. Uropod 3 rami broad; outer ramus with 2 large recurved distal robust setae. Telson subtriangular; cusps small or absent; denticles absent.

Species composition. Cymadusa contains 30 species: C. aungtonyae Peart, 2002; C. bilobata (Ruffo, 1969); C. bilobata pillipes (Ledoyer, 1984); C. brevidactyla (Chevreux, 1907); C. cavimana (Sivaprakasam, 1970); C. chalongana Peart, 2002; C. chuawe sp. nov.; C. compta (Smith, 1873); C. crassicornis (Costa, 1857); C. elegantis sp. nov.; C. filosa Savigny, 1816; C. grossimana Ledoyer, 1984; C. hawaiensis (Schellenberg, 1938); C. heronensis sp. nov.; C. imbroglio Rabindranath, 1972; C. jiigurru sp. nov.; C. ledoyeri Peart, 2004; C. lunata Myers, 1985; C. mauritiensis (Ledoyer, 1978); C. microphthalma (Chevreux, 1901); C. munnu Poore & Lowry, 1997; C. oceanica J.L. Barnard, 1955; C. panwa Peart, 2002; C. pemptos sp. nov.; C. setosa (Haswell, 1879); C. tattersalli Peart, 2004; C. thagaay sp. nov.; C. tishana sp. nov.; C. vadosa Imbach, 1967; C. wistari sp. nov.

Distribution. Species of Cymadusa live predominantly in tropical regions worldwide. Few species are recorded from cool temperate waters (e.g., C. compta from the warm temperate to boreal western Atlantic, and C. elegantis from Tasmania), and none are known from polar regions.

Habitat. Cymadusa species tend to be non-specific in habitat preference. They are known from a wide range of brown seaweed species, and also from coral rubble and epiphytes on other marine organisms. Original descriptions of Cymadusa species and various ecological studies (e.g., Appadoo & Myers 2003; Zimmerman et al. 1979; Poore & Lowry 1997) should be consulted for details of habitat and substrate

Remarks. Cymadusa is similar morphologically to the genera Paragrubia Chevreux, 1901, Amphithoides Kossmann, 1880 and Plumithoe Barnard & Karaman, 1991 . Cymadusa differs from Paragrubia by the length of the antenna 1 accessory flagellum and also the shape of uropod 3 rami. Cymadusa differs from Amphithoides by its short and broad rather than long and narrow uropod 3 rami. Cymadusa differs from Plumithoe by the presence of the first antennae accessory flagellum.