Scaly-foot gastropod

Scaly-foot / Sea pangolin
Apertural view of a dark globose shell. There is a foot extended from the aperture. The foot is covered by dark scales.
Chrysomallon squamiferum from Longqi. Scale bar is 1 cm
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Neomphaliones
Order: Neomphalida
Family: Peltospiridae
Genus: Chrysomallon
Chen, Linse, Copley & Rogers, 2015
Species:
C. squamiferum
Binomial name
Chrysomallon squamiferum
Chen, Linse, Copley & Rogers, 2015[2]
Synonyms[2]

Crysomallon squamiferum (orth. error)

Chrysomallon squamiferum, commonly known as the scaly-foot gastropod, scaly-foot snail, sea pangolin, or volcano snail[3][4] is a species of deep-sea hydrothermal-vent snail, a marine gastropod mollusc in the family Peltospiridae.[2] This vent-endemic gastropod is known only from deep-sea hydrothermal vents in the Indian Ocean, where it has been found at depths of about 2,400–2,900 m (1.5–1.8 mi). C. squamiferum differs greatly from other deep-sea gastropods, even the closely related neomphalines.[5] In 2019, it was declared endangered on the IUCN Red List,[6] the first species to be listed as such due to risks from deep-sea mining of its vent habitat.[7]

The shell is of a unique construction, with three layers; the outer layer consists of iron sulphides, the middle layer is equivalent to the organic periostracum found in other gastropods, and the innermost layer is made of aragonite. The foot is also unusual, being armored at the sides with iron-mineralised sclerites.

The snail's oesophageal gland houses symbiotic gammaproteobacteria from which the snail appears to obtain its nourishment. This species is considered to be one of the most peculiar deep-sea hydrothermal-vent gastropods, and it is the only known extant animal that incorporates iron sulfide into its skeleton (into both its sclerites and into its shell as an exoskeleton).[2] Its heart is, proportionately speaking, unusually large for any animal: the heart comprises approximately 4% of its body volume.[5]

  1. ^ Sigwart, J.; Chen, C.; Thomas, E.A. (2019). "Chrysomallon squamiferum". IUCN Red List of Threatened Species. 2019: e.T103636217A103636261. doi:10.2305/IUCN.UK.2019-2.RLTS.T103636217A103636261.en. Retrieved 19 November 2021.
  2. ^ a b c d Cite error: The named reference Chen 2015 was invoked but never defined (see the help page).
  3. ^ "Meet the Bizarre Sea Snail That Builds Its Own Iron Suit of Armor". 15 November 2021.
  4. ^ Cite error: The named reference AutoAP-1 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Chen 2015 heart was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference AutoAP-2 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference AutoAP-3 was invoked but never defined (see the help page).