Meeting Abstract

54.8  Saturday, Jan. 5  The price of being special: consequences of specialisation of the hyolingual system in lizards. SCHAERLAEKEN, V*; HERREL, A; Univ. of Antwerp; Univ. of Antwerp vicky.schaerlaeken@ua.ac.be

The form and function of the squamate hyolingual apparatus shows a tremendous diversity. Based on their tongue morphology, squamates can be divided into two groups: Iguania and Scleroglossa. While Iguania posses a short fleshy tongue that is used both for prey capture and transport, scleroglossans have an elongated, bifurcate tongue that is typically not used for prey capture. In generalised squamates both the hyoid and tongue move antero-posteriorly during feeding to transport food towards, and into the oesophagus. However, in lizards with a highly specialized tongue or hyoid, a decoupling of the tongue-hyoid system is predicted (e.g. chameleons with a ballistic tongue projection mechanism or Anolis lizards with a specialized hyoid used to extend their dewlap). Consequently, the functional role of prey transport will be assigned to one system only. For example, after retraction of the tongue into the buccal cavity in chameleons, the tongue retractor can no longer generate force and large displacements of the hyoid will be needed to transport the prey. Moreover, a decoupling of tongue and hyoid movements is predicted to have consequences on the efficiency of prey transport and swallowing. We test these hypotheses using cineradiography to quantify the movements of the jaws, the hyoid and the tongue during the transport and swallowing of prey differing in their size and mechanical properties.