The Migration of a Red Sea Crab through the Suez Canal

THE Suez Canal was completed in 1869, and since that date it has been invaded from both ends by plants and animals. Some members of the Red Sea fauna have passed right through the Canal to spread into the Mediterranean, and some Mediterranean species have reached the Red Sea. Had periodic faunistic surveys of the Canal been made since the beginning, valuable information would have been obtained concerning the stages in the mixing of two entirely different faunas. Unfortunately this has not been done. To my knowledge there are only three published investigations of the Suez Canal fauna. The first, dated 1882 (C. Keller, ``Die Fauna im Suez Kanal'', Denkschriften der schweizerischen Gesellschaft für die gesamte Naturwissenschaften, Bd. 28), deals largely with the invertebrates; the second, in 1902 (J.-B. Tillier, ``Le Canal de Suez et sa fauna ichthyologique'', Mém. de la Soc. Zool. de France, t. 15, p. 279), concerns the fish alone; and the third, dated 1905 (L. Tillier et A. Bavay, ``Les mollusques testacés du Canal de Suez,'' Bull. de la Soc. Zool. de France, t. 30, p. 170, and t. 32, p. 129), deals with the molluscs. It is proposed this year to repeat the earlier work in order to see what further immigration has taken place since then, and further to study the factors which permit and prevent migration.