Imogine mediterranea (Galleni, 1976) Jennings & Newman, 1996

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 : 62

Imogine mediterranea (Galleni, 1976) Jennings & Newman, 1996

Morphological features. The body is relatively thick and fleshy. The dorsal face is white containing several brown spots. It is almost the only species that could be handly collected without using a paint brush. Two retractile nuchal tentacles are present ( Fig. 1D ). Tentacular and cerebral eyes are present. Marginal eyes form a row along the entire body margin. The pharynx is voluminous and opens in a mouth located in the half of body.

Reproductive features. The copulatory apparatus is located in the last fourth of body. The sperm ducts open into a tripartite anchor shaped seminal vesicle connected to a free prostatic vesicle by a prostatic canal. The ejaculatory duct is narrow and leads to a male genital pore located 0.5 mm anterior to the female pore. The latter leads to a vagina provided with epithelial folds.

Developmental study. The development is indirect and a four-lobed Götte's larva hatchs. It is provided with 3 eyes ( Fig. 5B ).

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.

Figure 5. Hatched juveniles and larvae in polyclads A: A twelve eyed juvenile of Leptoplana mediterranea, scale bar: 0.05 mm B: Götte’s larva of Imogine mediterranea: lateral view, scale bar: 0.03 mm C: Müller’s larva of Prosthiostomum siphunculus: lateral view, scale bar: 0.03 mm D: Müller’s larva of Prosthiostomum siphunculus: apical view showing the three eyes (arrowheads), scale bar: 0.03 mm.