Lutraria oblongaLutraria oblonga, common name the oblong otter shell, is a species of large saltwater clam, a marine bivalve mollusc in the family Mactridae.DescriptionLutraria oblonga has a shell that can grow to a length of 11–15 cm.Right and left valve of the same specimen:DistributionL. oblonga is present in the North African coast of the Mediterranean Sea, in the Red Sea and in the eastern coast of Africa.