Picture details
Genus Prostheceraeus
Species giesbrechtii
Authority Schmarda, 1859
Family Euryleptidae
Order Polycladida
Location Porto Santo Island (near Madeira) 
© Copyright Prof. Dr. Peter Wirtz,
University of Madeira,
Comments P. giesbrechtii is one of the most common flatworm species of the Mediterranean Sea and can also be found in the temperate Eastern Atlantic.