Claim: Semirossia tenera is possibly also present in the southwest Atlantic and grows to 50 mm in mantle (a significant part of the anatomy of molluscs) length.
Evidence: S. tenera is possibly also present in the southwest Atlantic, specifically off the coasts of Suriname, French Guiana, Brazil, and Uruguay, although the latter records are questionable. S. tenera grows to 50 mm in mantle length (ML). The mantle (also known by the Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.