Article · Wikipedia archive · Last revised Jul 7, 2026

Hyaline shield

The hyaline shield is a part of the radula in many kinds of molluscs. It serves as an attachment point for the muscles that retract the radula, and is thus located on the upper surface of the radula, arching backwards into the mouth. This retraction fires any food particles backwards into the mouth.

Last revised
Jul 7, 2026
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The hyaline shield (hy.sh.) attached to an Octopus radula. Scale bar: 0.5 mm. source ↗

The hyaline shield is a part of the radula in many kinds of molluscs. It serves as an attachment point for the muscles that retract the radula, and is thus located on the upper surface of the radula, arching backwards into the mouth. This retraction fires any food particles backwards into the mouth.1

The hyaline shield is constructed from chitin1 and is present in most radula-bearing molluscan groups, including the cephalopods1 and the chitons.2

References

References

  1. Messenger, J. B.; Young, J. Z. (1999). "The Radular Apparatus of Cephalopods". Philosophical Transactions: Biological Sciences. 354 (1380): 161–182. doi:10.1098/rstb.1999.0369. JSTOR 56840. PMC 1692476.
  2. Shaw, JA; Macey, DJ; Brooker, LR; Clode, PL (2010). "Tooth use and wear in three iron-biomineralizing mollusc species". The Biological Bulletin. 218 (2): 132–44. doi:10.1086/bblv218n2p132. PMID 20413790.