Cymadusa filosa Savigny, 1816

Appadoo, C & Myers, A. A., 2004, Corophiidea (Crustacea: Amphipoda) from Mauritius, Records of the Australian Museum 56 (3), pp. 331-362 : 343-344

Cymadusa filosa Savigny

Cymadusa filosa Savigny, 1816 .— Krapp-Schickel, 1982: 106, figs. 71–72.— Ledoyer, 1982 (form of seagrasses): 135, fig. 45H.—Appadoo & Steele, 1998: 639.

Material examined. 1433, 12♀♀, 7 juv., AM P60632, from Padina sp. , La Cuvette (20°00'S 57°34.2'E), 14 May 1998 ; 833, 11♀♀, 6 juv., AM P60633, from Enteromorpha sp. , Sargassum sp. , Hypnea

sp., Tamarin (20°19.5'S 57°22'E), 11 October 1999; 833, 24♀♀, AM P60634, from Padina sp. Bain Boeuf, 13 December 1999; 733, 18♀♀, AM P60635, from Halodule uninervis and Hypnea sp. , Flic-en-Flac (20°16.5'S 57°21.7'E), 27 January 2000.

Diagnosis. Antenna 1 accessory flagellum 2-articulate, article 2 small. Gnathopod 1 coxa distal margin lined along its whole length with slender plumose setae, 0.3× length of coxa; basis slender, 3.8× as long as broad, anterodistal lobe weakly developed, anterior margin with dense plumose setae; carpus elongate, 2.8× as long as broad; propodus, palm oblique. Gnathopod 2 coxa subquadrate, 1.3× as long as broad, distal margin lined with slender plumose setae 0.5× the length of coxa; basis 2.8× as long as broad, anterior margin with dense groups of long slender plumose setae; carpus subtriangular, subequal in length and breadth, anterior margin with dense groups of long slender plumose setae; propodus 1.6× as long as broad, anterior margin with dense groups of plumose setae; palm weakly excavate; dactylus robust, strongly curved and shorter than palm. Coxae 3–4 distal margin lined with long slender plumose setae. Epimera 1–3 produced into a small posterodistal tooth. Telson distally rounded, telsonic cusps present.

Female, antenna 2 similar to that of male but with groups of fine slender setae instead of dense plumose seta. Gnathopod 1 anterior margin of basis with few slender setae; carpus elongate, 1.8× as long as broad. Gnathopod 2, anterior margin of basis, carpus and propodus with few slender setae; propodus palmar margin weakly excavate.

Type locality. Egypt .

Distribution. Mediterranean, Madagascar, Mauritius.

Habitat. This is a very common and abundant species in the intertidal and shallow-subtidal zone and was collected from several sites at depths less than 1 m. It lives mostly amongst brown and green algae.

Remarks. Material from Mauritius agrees with the description given by Krapp-Schickel (1982) of material from the Mediterranean. It also closely resembles the C. filosa described by Ledoyer (1982) from seagrasses in Madagascar. Males and females of this species are distinguished from other species of Cymadusa from Mauritius by the presence of slender plumose setae along the entire distal margin of coxae 1–4.