Fancy Goldfishes have been bred and selected down to have shorter bodies than their wild counterparts, therefore having less area for the organs to function as properly as they would normally. This includes digestion, spawning, and buoyancy.
Goldfish do not have a "stomach" per se, they have an enlarged intestinal bulb where food from the esophagus is deposited- their natural diet is mostly algae and very soft plant materials, so they do not necessarily need " stomach acid" to break these down. However, since the onset of rigorous selection and breeding along with the development of differing body types, additional tissue areas (like Wen in Oranda and Ranchu) these "extra " features require very high protein intake to develop. If goldfish are fed with food very high in protein but are not balanced with algae/plant matter, it can possibly cause bloat since they cannot properly "digest" protein rich, meaty food.
Swim bladder problems with goldfish happen for numerous reason- Poor water quality, genetics, stress or injury and possibly certain foods.
The first item is poor water quality- again, most goldfish now are products of heavy selective breeding and inbreeding- they are not as resilient as their wild counterparts, let alone the less fancy varieties like Comets and Shubunkin. While the less fancy types can tolerate less ideal water quality (although this is not endorsed at all, please keep your aquatic animals clean and healthy) Fancy Goldfish are intolerable of poor water quality, and tend to develop more problems because of this, swim bladder issues being one of these. Poor water quality usually leads to infections, ammonia burns or even death if not resolved quickly.
Swim bladder problems with goldfish happen for numerous reason- Poor water quality, genetics, stress or injury and possibly certain foods.
The first item is poor water quality- again, most goldfish now are products of heavy selective breeding and inbreeding- they are not as resilient as their wild counterparts, let alone the less fancy varieties like Comets and Shubunkin. While the less fancy types can tolerate less ideal water quality (although this is not endorsed at all, please keep your aquatic animals clean and healthy) Fancy Goldfish are intolerable of poor water quality, and tend to develop more problems because of this, swim bladder issues being one of these. Poor water quality usually leads to infections, ammonia burns or even death if not resolved quickly.
Genetics are also at play here, since most goldfish sold are bred en masse in huge farms in Asia, there is some degree of QC there but these fish are usually sold as "pets" and therefore are not specifically bred to have better disease or "problematic" resistance. The higher quality fishes, which in turn also cost much more, are bred with rigorous and strict guidelines and culling, so in theory you should have less issues with them.
Stress and Injury can happen frequently with Fancy Goldfish if their habitat is not kept well, if there are objects they can damage themselves on, or if they have tank mates which can cause duress, which in turn can cause the fish to eat rapidly, erratically, become constipated or stop eating altogether.
Feeding is also a major issue when it comes to swimbladder- if the fishes are fed too often, foods not nutritionally balanced, and some floating foods can cause issues with their intestines and bladder. As we said before, balance is of utmost importance when it comes to nutrition since these fish do not have a stomach to break down and digest these foods- all of their nutrition is taken in through their gut/ intestines. If they are fed food which does not sink immediately, do try to soak them first- this helps to purge the excess air that is trapped in the food, and it will also help the food to soften a bit first. When Fancy goldfish eat foods that float or tent to be dry/ hard, once it passes into their gut it will slowly enlarge with water, and the air which may also have been in the food will be released into the gut, which will then cause the gut to become enlarged and possible air-filled. This enlargement of the gut along with air in the intestines can cause unnecessary pressure within the fish, which can cause the swimbladder to involuntarily expand or deflate, along with excess air trapped in the intestine. since the food may cause a back up as well (constipation) it can lead to infections as well as duress to the fish if not resolved quickly.
Feeding sinking versions of these foods as well as feeding heavily plant based foods will help the fish from incurring these problems, but it is not the only reason for a fish to develop swim bladder issues- there are multiple factors at play when keeping fancy goldfish.
Feeding sinking versions of these foods as well as feeding heavily plant based foods will help the fish from incurring these problems, but it is not the only reason for a fish to develop swim bladder issues- there are multiple factors at play when keeping fancy goldfish.