I got a small flame angel a few days ago and he seems super healthy and very active but I saw him poop one time and there was like a white cloud and a long white thing came out that was stuck to him for a few seconds then fell of and I heard that’s bad. Lfs said he was just feeding brine shrimp but I feed him brine shrimp and ocean nutrition prime reef flakes but he stopped eating flakes for some reason. I have other fish in my tank and I don’t want anything to spread so I really need some advice asap. Also the long white thing went in my filter so should I clean my filter out?
You cannot visually determine the cause of mucus in feces, kind of like how you can't really tell the reason a person coughs. Here is some text that I wrote on the subject:
Excess mucus in fish feces: this will present as white or light colored, stringy fecal material
that often hangs from the fish’s anus for a longer than normal period. There are a number of different causes
for this, some benign, others very serious. Without access to a microscope, there is little that can be
done to diagnose this issue effectively.
Idiopathic mucus feces: this fancy term is just to describe white mucoid bulky feces of no serious
consequence, but of an unknown cause. Some suspicion is that this can be caused by changes in diet
or diets high in fats.
Starvation: Fish that have no food moving through their bowels may excrete white mucoid feces with
little bulk to them. The primary diagnostic for this issue is evident in that the fish won’t been
seen to be eating. Resolving the anorexia is of course the prime focus to resolve this issue.
Bacterial infection: internal bacterial infections can cause stringy feces as well. While some of
these may resolve on their own, medicated foods containing a broad spectrum, gram negative oral
antibiotic may be required.
Metazoan infections: multicellular worms are often blamed for mucoid feces, but in reality, they
are almost never the root cause for this, and really, can only be diagnosed through looking for
their ova in fecal samples. Fish can harbor tapeworms and nematodes without producing mucoid feces.
Protozoan infection: Hexamita and related diplomonad flagellate protozoans very frequently cause
white stringy feces, especially in newly acquired clownfish. Metronidazole is the most frequent
treatment for this issue. It can be dosed orally at 25 mg per kg of fish body weight, or 5 g in a
kg of food. However, it is a very bitter medication, and some fish will refuse to feed on food
containing it. It can be dosed in the water at 25 mg/l, but this is more effective in treating
marine fishes, as freshwater fish do not “drink” aquarium water.
Coccidia: These microscopic, spore-forming, single-celled parasites are common diseases in dogs and
cats. In fish, they cause epithelial necrosis of the gut, enteritis and the copious production of
mucus (Noga 2010). These cannot be diagnosed without microscopic examination, and there is no well
researched cure for this in fishes, although Toltrazuril has been tested.
Constipation: This malady is often given as a cause for stringy feces, but it is not as common as
one would think. When it is seen, the feces are usually dark, not light in color. Often touted as a
“cure for constipation”, many aquarists add Epsom salts (magnesium sulfate) to the aquarium’s water
– do not do this in marine aquariums, its use is primarily as a tonic/dip for freshwater fish.
Seawater formulas already contain between 7 and 19 grams of magnesium sulfate per gallon (depending
on the recipe). NSW magnesium level is around 1200 ppm and sulfur is around 840 ppm. Some benefit
might be seen using it as a dip in additional concentrations, but adding a small amount to a marine
aquarium itself has no benefit. Epsom salts do have some possible benefit when mixed into the food
as a 3% by weight adjunct. Another commonly heard remedy for constipation is; “feed fresh peas”.
This is an effective cure for fancy goldfish and Malawi cichlids that develop constipation and
bloating. Again, overextrapolation has marine aquarists trying to feed peas to carnivorous fish,
etc. The best method to enhance gut motility in fish is to feed frozen adult brine shrimp – not as
a permanent diet, just long enough to get the constipation
resolved.
Jay
