In addition, with the gradual reduction of the yolk sac and the emergence and development of the gas bladder
and pectoral fins, the larvae began to move horizontally at different levels of water column.
This trend is explained by the fact that in the early days old larvae of marine fish are very fragile, with low survival, as the energy demand and protein necessary for morphological changes such as formation of the mouth, anus, pigmentation of the eyes, gas bladder
, fins, scales and other organs of the digestive system is very large (Yufera & Darias, 2007).
The gas bladder
lies at the top (dorsal) of the abdominal cavity and looks like a white sausage running along the underside of the backbone.
Researchers at Texas A&M University tested venting or fizzing, in which a hollow needle punctures the gas bladder
to relieve pressure, and rapid recompression, which quickly returns fish to the depth of capture where symptoms are alleviated, on red snapper* Methods of recompression include weighted hooks or jigs, weighted cages, and pressure-activated devices like the SeaQualizer, which the researchers employed in this study.
Instead of venting the gas into the atmosphere, it is collected in the gas bladders
and pumped to liquefier equipment.