Body narrow and elongate, widening at the level of each ceratal group. Rhinophores elongated with an acute apex and papillated posterior surface. Oral tentacles thin and longer than the rhinophores. Anterior foot corners long and tentacular. Cerata arranged in five or six groups, each one elevated directly from the notum.
general body color translucent pinkish or pale purple, with three vermilion or crimson longitudinal lines from the head to the posterior limit of the tail, one of them mid-dorsal and a pair of lateral. Irregular white pigmentation may be present all over the body. Rhinophores, cerata, and angles of the foot translucent or opaque white basally and with purple pigment towards the tip.
common size :
up to 40 mm in length; specimen from Israel: 5 mm.
There are three Mediterranean species of Flabellina that resemble at first glance F. rubrolineata because of their violet general coloration (F. affinis, F. pedata and F. ischitana), but the three red or purple longitudinal lines along the length of the animal are diagnostic for F. rubrolineata. Besides, the Mediterranean species have lamellate rhinophores instead of papillated.
BIOLOGY / ECOLOGY
This red-lined aeolid is common on shallow reef and walls in the tropical Indo-Pacific, where it feeds on the hydroids Halocordyle disticha or Eudendrium spp. (Willan and Coleman, 1984; Gosliner et al., 1996).
the specimen from Ashqelon was found on rocky bottoms, at 12 m depth.