Has a Swim Bladder?

The swim bladder is located in the body cavity and is derived from an outpocketing of the digestive tube. It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking.

Which class of fish has a swim bladder?

Bony fish differ from fish like sharks and rays in the chondrichthyes class. Instead of cartilage, bony fish have bones. Bony fish also have a swim bladder. The swim bladder is a gas-filled sac that helps keep bony fish buoyant!

What are the two types of swim bladders?

Swim bladders are of two basic types. An 'open' swim bladder (Physostomous) is connected, via a pneumatic duct, to the gut. Fish with this type of swim bladder, herrings for instance, must gulp air at the surface to inflate the swim bladder, and then burp or fart air to deflate it.