Question

Weberian ossicles are found in
(a) Frog
(b) Snakes
(c) Fishes
(d) Birds

Answer 1

Hint: Weberian apparatus or Weberian ossicle is an anatomical structure that plays the role of an amplifier of sound waves underwater. This apparatus consists of minute bones and grows to connect to the auditory system of the organisms.

Complete step by step answer:
Weberian ossicles are anatomical structure chains of 4 small bone pieces that are found in fishes and connect the swim bladder to the auditory system of these fishes and acts as an amplifier. It is found mainly in Ostariophysi. They are for the enhancement of hearing by pressure changes caused by sound waves from the swim bladder to the ear.

Additional Information: Let us know some more about this Apparatus:
Structure: They consist of 4 small bones namely the claustrum, scaphium, intercalary, and tripus. The first one lies in front of the scaphium and it is the smallest anterior piece. The other three form an articulated chain. Scaphium is slightly larger, broader, and compressed and has a ventral peg-like process that articulates with a depression in the centrum of the first vertebrae. The intercalary is present as either a small nodule of bone in the ligament as in the silurians or as a rod-like piece as in carps. Tripus is the largest bone and has three processes named as interior, middle, and posterior.
Location- The Weberian ossicle is located on each side of the anterior vertebrae and extends between the membranous labyrinth and air bladder on the sides.
Function- Its function is to assist in auditory function by the transmission of vibrations from swim bladder to endolymph of internal ear. These are sensitive to sound frequencies and have a hydrostatic function. Detection of variation in atmospheric pressure and sound direction was also done by the Weberian ossicle.
So, the correct answer is ‘fishes’.

Note: This ossicle was first observed by Weber in 1820. Therefore, it was named after him as a Weberian ossicle. These are characteristic features of the superorder Ostariophysi which is the second-largest superorder of fish. The ossicle connects the auditory system of these fishes to the gas bladder and connects the wall of the gas bladder to the Y shaped lymph sinus.