TAKEOFF
BASS SCIENCE
ALL ABOUT GILLS
HOW THEY WORK AND HOW TO PROTECT THEM
By TJ Maglio
ILLustRAtIoNs by kevIN hANd
everyone knows that virtually all fish, bass included,“ breathe” with the aid of gills rather than lungs. In addition to fish, many amphibians, mollusks and crustaceans also use gills to get the oxygen they need to survive.
Although most anglers certainly know bass have gills, it’ s a good bet far fewer know anything about how they work. Here’ s a look at the form and function of gills and how to protect them so fish can be released unharmed.
Why gills?
Human lungs draw oxygen out of the air and remove carbon dioxide through gas exchange across a matrix of microscopic air sacs called alveoli. The diaphragm inflates and deflates the lungs as we breathe.
Water is approximately 777 times denser than air and contains only a fraction of the oxygen. If your lungs had to“ breathe” water, your diaphragm wouldn’ t be nearly strong enough to inflate or deflate, and your alveoli couldn’ t produce nearly enough oxygen to sustain life.
Given the difficulty of breathing in water, fish evolved gills, which contain thousands of filaments connected to a vast network of blood-rich capillaries.
gills at Work gill filaments
This provides a large surface area for extracting oxygen from the water and secreting carbon dioxide.
how they Work
Most freshwater fish have three pairs of gills aligned on each side of their throat. The gill filaments are attached to the bony gill arches and covered by the operculum, which is the plate-like structure along the side of a fish’ s head.
Bass“ inhale” by contracting their throats to draw water in through their mouths, and then“ exhale” by opening the operculum to allow the water to escape out the gill slits.
lamella plates
1. Water comes in the mouth. 2. As the water moves across the gills, oxygen
diffuses into the capillary network running through the lamella plates, which are substructures of the gill filaments that provide additional surface area for absorbing oxygen.
3. Carbon dioxide and other waste products diffuse back into the water.
protecting gills
In addition to carefully handling bass to avoid physical trauma to the gills and other organs, there are several ways to ensure you’ re protecting bass gills when fishing.
Keep them in the water – Gill tissues will be damaged by prolonged exposure to air. Release fish quickly, and try to minimize their exposure to air when culling or while at the weigh-in stand.
Don’ t touch them – Try to avoid“ gilling,” or lifting bass by the gill plates. This can seriously damage the gill tissue.
Don’ t use peroxide – Some anglers still believe that adding hydrogen peroxide to livewell water can increase dissolved oxygen. It can’ t, and it actually causes damage to sensitive gill tissue. Stick with cool water and approved livewell treatments.
Unhook fish quickly and carefully – This goes without saying, but ripping a hook through gills can severely damage them, so make every effort to unhook deeply hooked fish quickly and cleanly. Keep a quality needle-nose plier handy, and if possible unhook bass in a landing net that’ s submerged. When a bass is hooked in its gills, consider working the hook loose from behind the gill plate, rather than through the mouth. This is often the best way to remove it without causing excess damage.
22 flWfIshIng. Com I november-deCember 2017