Like other members of the family Cranchiidae, Teuthowenia megalops possess a remarkable flotation system that enables them to remain in the water column at neutral buoyancy.
The system uses enormous bilobed coelomic chambers filled with ammonium chloride derived as waste products from their nitrogen metabolism.
The ammonium chloride has a lower density than water, which enables the squid to float.
In experiments, puncturing the chambers and draining the ammonium chloride resulted in the squid sinking rapidly.
The chamber is also lined with muscles that contract and expand regularly in peristaltic waves.
The movement draws water into the mantle cavity and pushes it out again through the funnel, aerating the gills in the process.

As a result of this adaptation, Teuthowenia megalops are sluggish swimmers.
Unlike other squids, they do not need to contract their mantle muscles to breathe, but their modified flotation and respiratory systems restrict their ability to jet away from threats.
They generally float passively in the "cockatoo" posture typical of glass squids (which are also known as cockatoo squids for this reason).
They resemble a horizontal cockatoo, hence the name.
In this posture, they rotate around their spindle-shaped digestive glands, the only internal organs of the squid clearly visible through their mostly transparent bodies.
Regardless of the direction their heads or mantles are facing, the digestive glands are always kept oriented vertically.
Like other members of the family Cranchiidae, Teuthowenia megalops possess a remarkable flotation system that enables them to remain in the water column at neutral buoyancy. The system uses enormous bilobed coelomic chambers filled with ammonium chloride derived as waste products from their nitrogen metabolism. The ammonium chloride has a lower density than water, which enables the squid to float. In experiments, puncturing the chambers and draining the ammonium chloride resulted in the squid sinking rapidly. The chamber is also lined with muscles that contract and expand regularly in peristaltic waves. The movement draws water into the mantle cavity and pushes it out again through the funnel, aerating the gills in the process.
As a result of this adaptation, Teuthowenia megalops are sluggish swimmers. Unlike other squids, they do not need to contract their mantle muscles to breathe, but their modified flotation and respiratory systems restrict their ability to jet away from threats. They generally float passively in the "cockatoo" posture typical of glass squids (which are also known as cockatoo squids for this reason). They resemble a horizontal cockatoo, hence the name. In this posture, they rotate around their spindle-shaped digestive glands, the only internal organs of the squid clearly visible through their mostly transparent bodies. Regardless of the direction their heads or mantles are facing, the digestive glands are always kept oriented vertically.
Teuthowenia megalops