Syrinx aruanus is a species of extant gastropod with the largest shell. The height of the shell can be up 72.2 cm. The largest specimen is stored in the Houston Museum of Natural Science. The volume of the animal is also very large. It is thought to be more voluminous than the largest extinct snail Campanile giganteum.
Syrinx aruanus is a marine sea snail and it belong to the family Turbinellidae.
I thank Jan Linhart, who has taken the photo of the shell in the Phuket Sea shell Museum, Thailand. I do not know exact measurements of this shell.
Specimen of the shell height 91 cm was previously reported in the literature, but the reported size was wrong.
It may be also the heaviest extant snail (reaching up to 18 kg?), but I found no proper reference.
What are the limits of gastropods?
McClain C. R., Balk M. A., Benfield M. C., Branch T. A, Chen C., Cosgrove J., Dove A. D. M., Gaskins L. C., Helm R. R., Hochberg F. G., Lee F. B., Marshall A., McMurray S. E., Schanche C., Stone S. N. & Thaler A. D. 2015: Sizing ocean giants: patterns of intraspecific size variation in marine megafauna. – PeerJ 3:e715. DOI: 10.7717/peerj.715.
Taylor J. D. & Glover E. A. 2003: Food of giants – field observations on the diet of
Syrinx aruanus (Linnaeus, 1758) (Turbinellidae) the largest living gastropod. pp. 217-223. – In: Wells F. E., Walker D. I. & Jones D. S. (eds) 2003: The Marine Flora and Fauna of Dampier, Western Australia. Western Australian Museum, Perth.