Scaly-foot gastropod

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Scaly-foot gastropod
Crysomallon squamiferum.jpg
Two preserved specimens of Crysomallon squamiferum
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Neomphalina
Superfamily: Neomphaloidea
Family: Peltospiridae
Genus: Crysomallon
Species: C. squamiferum
Binomial name
Crysomallon squamiferum
Van Dover et al., 2001[1]

Crysomallon squamiferum, common name the scaly-foot gastropod, is a species of deep sea hydrothermal vent snail, a marine gastropod mollusk in the family Peltospiridae.[2]

The name Chrysomallon or Crysomallon squamiferum is listed in WoRMS because it is occasionally encountered on the web, and has also been used in a few academic papers. However, the name has never been validly published in the sense of the International Code of Zoological Nomenclature. [3]


This species was discovered in 2001, living on the bases of black smokers at the Kairei hydrothermal vent field, on the Central Indian Ridge, just north of the Rodrigues Triple Point and about 2,420 metres (7,940 ft) below the surface.


The snail's foot is very unusual in that it is armored with iron-mineral scales. It is protected by scale-shaped sclerites composed of iron sulphides[4] greigite and pyrite.[5] No other animal is known to use iron sulfides in this way.

two varieties of Scaly-foot gastropod

The snail's shell is also unusual. The shell structure is composed of three layers. The outer layer is about 30 μm thick, and is made of iron sulphides, containing greigite Fe3S4. This makes this gastropod the only metazoan known so far that employs this material in its skeleton. The middle shell layer is organic, and is also the thickest of the three (about 150 μm). It is comparable to the periostracum, a thin protein coating found on other snail shells. The innermost layer is made of aragonite, a form of calcium carbonate that is commonly found both in the shells of mollusks and in various corals.[2]

Each layer contributes to the effectiveness of the snail's shell in different ways. The middle organic layer appears to absorb the mechanical strain and energy generated by a squeezing attack (as by the claws of a crab), making the shell much tougher. The organic layer also acts to dissipate heat.[6]

The United States military is currently funding research on the armor of the snail in hopes of developing insights into new military armor designs.[6]


  1. ^ Van Dover CL, Humphris SE, Fornari D, Cavanaugh CM, Collier R, Goffredi SK, Hashimoto J, Lilley MD, Reysenbach AL, Shank TM, Von Damm KL, Banta A, Gallant RM, Gotz D, Green D, Hall J, Harmer TL, Hurtado LA, Johnson P, McKiness ZP, Meredith C, Olson E, Pan IL, Turnipseed M, Won Y, Young CR 3rd, Vrijenhoek RC (2001). "Biogeography and ecological setting of Indian Ocean hydrothermal vents". Science 294 (5543): 818–23. doi:10.1126/science.1064574. PMID 11557843. 
  2. ^ a b Yao, H., Dao, M., Imholt, T., Huang, J., Wheeler, K., Suresh, S., and C. Ortiz (2010). "Protection Mechanisms Informed by the Unique Iron-Plated Armor of a Deep Sea Hydrothermal Vent Gastropod". PNAS. 
  3. ^ Bouchet, P. (2014). Chrysomallon Auct.. Accessed through: World Register of Marine Species at on 2015-02-16
  4. ^ Warén A, Bengtson S, Goffredi SK, Van Dover CL (2003). "A hot-vent gastropod with iron sulfide dermal sclerites". Science 302 (5647): 1007. doi:10.1126/science.1087696. PMID 14605361. 
  5. ^ Pickrell, John (2003-11-07). "Armor-Plated Snail Discovered in Deep Sea". National Geographic News. 
  6. ^ a b "Snail's iron armour eyed by military". CBC News. 2010-01-19. 

Further reading[edit]

External links[edit]