Euphysa tetrabrachia Bigelow, 1904

Buecher, Emmanuelle, Goy, Jacqueline, J, Mark & Gibbons, 2005, Hydromedusae of the Agulhas Current, African Invertebrates 46, pp. 27-69 : 48-49

Euphysa tetrabrachia Bigelow, 1904

Euphysa tetrabrachia: Bigelow 1904: 251 , pl. 1, fig. 1; Kramp 1961: 38; 1968: 10, fig. 15.

Description:Three immature specimens from three stations. Bell-shaped umbrella, taller than broad, with blunt apical projection; up to 4 mm in height. Exumbrella surface smooth. Mesoglea thick at apex, thinning laterally. Velum broad. Peripheral canal and four narrow radial canals present, latter with smooth margin; with neither centripetal nor apical canals. With four perradial marginal tentacle bulbs arising from umbrella margin, small. With one long tentacle, hollow, unbranched, filiform but bearing swollen cnidocyst clusters as warts irregularly along tentacle length. With three short filiform tentacles, bearing swollen cnidocyst clusters as warts irregularly along tentacle length. Manubrium spindle-shaped, as long as bell cavity is deep, not connected to radial canals by mesenteries. Mouth simple, circular, without lips; without gastric peduncle. Without ocelli on bulb of marginal tentacles. Without cnidocyst tracks on exumbrella. When mature, simple but folded gonads entirely encircling manubrium in central region only.

Material examined: H5041, H5042.

Comments: With the exception of E. aurata (Forbes, 1848) , which was recorded by Bouillon (1978 b) off the Seychelles, none of the other eight valid named species recognised by Bouillon and Boero (2000 b) have been recorded from the west Indian Ocean. Species can be differentiated by the number, relative length and distribution of cnidocysts on the tentacles, as well as by the shape and relative length of the manubrium. E. aurata is identifiable by its single tentacle, which bears rings of cnidocysts along its length.

Distribution: Scattered in tropical waters of Indian Ocean. This is the first record from the west Indian Ocean. Neritic.