In this article we will discuss about the dissection and structure of garden lizard (Calotes).
Hyoid Apparatus of Garden Lizards (Calotes):
The hyoid apparatus of Calotes occupies the same relative position in the buccal floor as in the case of frog.
Preparation:
Expose the basihyal of the hyoid apparatus following the procedure adopted for frog. Anteriorly it extends up to the base of the tongue. From the posterior end of the basihyal trace the hypohyals anterolaterally and ceratohyals posterolaterally. The first pair of branchial arches run posterolaterally in the neck region to the tympanum of the sides.
The second pair of branchial arches course posteromedially close to each other, support the tracheal tube and end in throat muscles. Since all the components except the first pair of branchial arches are cartilagenous, extreme care should be taken to expose them. Remove the hyoid apparatus by cutting the attachment muscles, treat with 10% KOH to clear, wash with water and mount in glycerine.
Structure:
(Fig. 29.10)
1. Basihyal:
A short, median cartilage, grooved lengthwise, with a tapering and curved anterior end.
2. Hypohyals:
Paired, slender, projected anterolaterally from the base of the basihyal.
3. Ceratohyals:
Paired, slender, directed posterolaterally from the hypohyal.
4. First branchial arches:
Paired, ossified, long and slender, directed postero- laterally from the base of the basihyal.
5. Second branchial arches:
Paired, directed posteromedially close to each other. The posterior ends narrow and curved.