cleithrum
English
Etymology
From Ancient Greek κλεῖθρον (kleîthron).
Noun
cleithrum (plural cleithra)
- (ichthyology) A large bone in fishes, which extends upward from the base of the pectoral fin and anchors to the cranium above the gills, forming the posterior edge of the gill chamber.
- 1993, J. J. Videler, Fish Swimming, Springer, page 66,
- The secondary arch consists of four pieces of bone, the posttemporal, supracleithrum, cleithrum and postcleithrum. […] The cleithrum is the largest piece and the other elements are attached to it.
- 2000, Melanie L. J. Stiassny, Chapter 6: The Skeletal System, Gary Kent Ostrander (editor), The Laboratory Fish, Academic Press, page 116,
- The main components of which are, from dorsal to ventral, the post-temporal, supracleithrum, cleithrum and the postcleithra. […] The cleithra of either side of the body are connected with the pharyngeal jaw apparatus and with the urohyal by the bilateral pharyngocleithralis musculature and the median sternohyoideus muscle.
- 2012, Jennifer A. Clack, Gaining Ground: The Origin and Evolution of Tetrapods, 2nd Edition, Indiana University Press, page 212,
- In Ichthyostega (Figs 5.2, 5.11), Acanthostega (Fig. 5.20), and also in Hynerpeton (Fig. 5.28C, D) and Ventastega, the cleithrum was relatively reduced, though it was still a substantial dorsally extensive blade.
- 1993, J. J. Videler, Fish Swimming, Springer, page 66,
Derived terms
- anocleithrum
- cleithral
- extracleithrum
- postcleithrum
- supracleithrum