Tonna luteostomaTonna luteostoma is a species of large sea snail, a marine gastropod mollusc in the family Tonnidae, the tun snails or tun shells. The species typically grows to a height of 100mm, width 85mm.TaxonomyThe accepted name Tonna luteostoma was proposed by Küster in 1857.DistributionTonna luteostoma can be found across Japan, where they are common. From 1976, the species began to appear in New Zealand waters, specifically in the Far North Aupourian geographical range.