Vitamin C and Cryptobia iubilans
I have been slowly losing my Cyprochromis fish for a while now. The symptoms can be described as "wasting disease"; the affected fish develop sunken bellies, stop eating after a while, and eventually die. This issue has only affected the Cyprochromis fish and has occurred in four different tanks/setups so far, affecting both the adult fish and the fry. Typically, it happens with one or two fish at a time, and I lose one every ten days or so. I've attempted to treat them a few times, targeting both parasites and bacterial infections, but it has not had any effect.
This week, I lost two of them, a young and an older one, so I sought vet help. I found someone who performed an autopsy on the dead fish. It turns out that he has an academic background in fish pathology and fish parasitology, so it was very interesting to talk to him about keeping fish and fish health. He also used to keep and breed Tanganyika cichlids, so I learned a lot from him.
It turns out that both had vitamin C deficiency (scurvy), and the adult also had a Cryptobia iubilans infection.
Vitamin C is required for healthy blood vessel development, specifically for collagen production in the walls of the vessels. In deficiency, the fish can essentially bleed out due to skin/scale hemorrhages. This was quite a surprise for me, as I had assumed that providing good food should contain all the necessary vitamins they need. I feed good pelleted and granulated foods, as well as frozen cyclops and artemia. I even feed my homemade salmon+spinach food sometimes, and I also accused this food as a potential source of some salmon parasites. I checked my dry food labels, and one lists L-ascorbic acid, while the other does not. It turns out that even if the food contains the vitamin (not just on the label), it may degrade over time. He advised me always to store the food in the freezer, even the dry food. I guess I should also purchase them in advance for only one or two months.
So, the therapy advice I received is to dissolve L-ascorbic acid in ethanol, spray the spread-out food with it, let it dry, and then feed it to the fish. Apparently, the same can be done with medicines, too.
As for Cryptobia iubilans, it's a more complicated issue. It's a flagellate organism that infects the stomach, causing granulomas that eventually block the lumen, leading to starvation and the observed symptoms of sunken bellies and slow, agonizing death. The disease may develop slowly, making it not immediately obvious when someone buys the fish. It seems to be a relatively common parasite in cichlids, and unfortunately, there is no known treatment for it except for aggressive culling of affected species and improving the fish's environment. Many fish can survive the infection, and in my tanks, it was likely the vitamin C deficiency that weakened the fish enough for the parasites to kill them.
So, let's hope that the vitamin C dosing does its thing, fingers crossed.
