The author describes his collecting trip in southern Tunisia during the end of March 2006. To his amazement, 18 specimens of Erosaria turdus (Lamarck, 1810) were collected in clay octopus traps that were left in shallow water off Jerba for one night. The specimens had an average length of 24.8 mm and were lighter coloured and lighter build in comparison to specimens collected in the south of Oman, one year earlier. Also, the Tunisian specimens lacked the distinct greenish tint that characterized the Omani specimens. Several other authors describe the occurrence of E. turdus in the Gulf of Gabes, and Castelli (2005) describes the catch of 4 specimens at 45 miles south of Lampedusa, Italy. It is suggested the species may be found in other areas within a relatively short timeframe. Most interesting is the question how the species managed to build up a large breeding population in this part of the Mediterranean; either colonization from the Suez canal or introduction of larvae in the vicinity of Jerba are suggested. Therefore, any information about the occurrence of the species in the Mediterranean outside the vicinity of the Gulf of Gabès is most welcome.