Glossary

Weberian apparatus

Anatomical structure connecting the swim bladder to the inner ear found in members of the fish superorder Ostariophysi.

Conveys sound and changes in pressure, and comprises four or five modified vertebrae.

Used in 5 species profiles

gas bladder
Gas-filled sac with 1-3 chambers, situated just below the vertebral column in most ray-finned fishes. Its primary function is to aid in buoyancy by offsetting the weight of heavier structures such as bone, but is also used for respiration or sound production in some species. Often reduced in benthic fishes and sometimes absent altogether. Also known as the air or swim bladder.
Ostariophysan
Fish of the superorder Ostariophysi, members of which are characterised by possession of a Weberian apparatus, i.e., the anterior four or five vertebrae are modified as a protective casing for the bony ossicles which connect the inner ear and swim bladder. The order contains such orders as Cypriniformes, Characiformes, Gymnotiformes, and Siluriformes.
tripus
The hindmost Weberian ossicle of the Weberian apparatus, touching the anterior wall of the swimbladder and connected to the intercalarium by a dense, elongate ligament.
vertebrae
Plural of vertebra.
Weberian ossicle
Any of the modified vertebrae comprising the Weberian apparatus in Ostariophysian fishes, individually named the claustrum, scaphium, intercalarium and tripus.