First confirmed record of the ragged sea hare Bursatella leachii Blainville, 1817 in Libyan waters.
The ragged sea hare Bursatella leachii, a well-established cryptogenic species in the Mediterranean Sea, was found in the Tripoli Harbour within the framework of the Project "Snowball", aiming at recording alien and cryptogenic species living along the Libyan coastline. The present record constitutes the first confirmed sighting of B. leachii in Libya. There are no certainties regarding possible pathway(s) of arrival of this species in the area. However, shipping or natural dispersal from nearby populations in the Mediterranean Sea constitute the most probable ones.