Yungia aurantiaca (Delle Chiaje, 1822) Lang, 1884

Gammoudi, Mehrez & Tekaya, Saïda, 2017, Suborders Acotylea and Cotylea (Polycladida): Study on morphological, ecological and reproductive features of some representative species from Tunisian coasts (Mediterranean), Ecologica Montenegrina 10, pp. 58-70 : 63-64

Yungia aurantiaca (Delle Chiaje, 1822) Lang, 1884

Morphological features. The length reaches 45 mm. The body is oval shaped. The colour of the dorsal face is orange with presence of white spots dispersed throughout its entirety. Two well-developed marginal tentacles are present ( Fig. 1E ). The ventral surface is whitish and shows the mouth, the male and female gonopores and the very developed true sucker. The cerebral eyes form two semicircular spots. The tentacular eyes are also present but they are more spaced than the cerebral.

Reproductive features. The male copulatory apparatus show a free prostatic vesicle and elongated seminal vesicle. The vagina is provided with a cement pouch. The two gonopores are separated. A true well developed sucker is present behind female genital pore. It is formed by a protuberance armed with muscular layer and modified epithelium.

According to our observation, the animal used its sucker to attach itself to a substrate fighting against strong action of waves.

Associated fauna. These flatworms are usually found associated with bryozoans and the tunicate Aplidium conicum (Olivi, 1792) .

Figures

Figure 1. Anterior dorsal region in A: Echinoplana celerrima. See the tentacular (te) and cerebral eyes (ce) forming two paramedian bands, scale bar: 0.5 mm. B: Letoplana mediterranea. See clusters of tentacular (te) and cerebral eyes (ce), scale bar: 0.5 mm. C: Discocelis tigrina. Note the presence of cerebral and tentacular eyes clusters, scale bar: 0.5 mm. D: Imogine mediterranea. Note the presence of two everted nuchal tentacles (arrows), scale bar: 0.5 mm. E: Yungia aurantiaca. See the two marginal tentacles (arrows) and cerebral eyes spots (arrowhead), scale bar: 1 mm. F: Thysanozoon brocchii. Dorsal faces provided with papillae and developed marginal tentacles (arrows), scale bar: 1 mm. G: Prostheceraeus moseleyi. Note the presence of marginal tentacles (arrows) and yellow marginal line, scale bar: mm. H: Prosthiostomum siphunculus. The cerebral eyes (ce) are not included in the semi circle formed by marginal eyes (me), scale bar: 1 mm.