Do Goldfish Poop and Pee?

If you own a goldfish or are considering buying one, then you have probbably about this question before:

Do goldfish poop and pee?

Sort of, goldfish poop through their vent (anus) located between the caudal fin (tail) and the anal fin. However, goldfish do not pee as they release ammonia through their gills.

With that interesting factoid out of the way, this article will cover pretty much everything you need to know about goldfish poop. Remember, goldfish don’t technically pee, so there isn’t really much to discuss there.

The Mechanics of Goldfish Pooping

The mechanics of goldfish pooping are actually slightly different than other fish for one pretty big reason – goldfish don’t have stomachs!

I know, I mention that factoid a lot on this website. I just find it so fascinating that these animals don’t have stomachs.

Anyway, the mechanics of a goldfish’s digestive track is not particularly difficult. This next section will cover the exact steps on how the digestive track of your goldfish works.

  1. Goldfish eats food by chewing it in their mouth.
  2. Swallowed food goes into the first intestine – called an intestinal bulb.
  3. Enzymes breakdown the food and absorb carbohydrates and fat.
  4. The food is pushed to the second intestine.
  5. This intestine absorbs the protein.
  6. All the remaining food is expelled via the vent.

And that’s it – it’s pretty simple. Goldfish are similar to birds in that this whole process does not take very long – a goldfish can eat and defecate the waste within 30 minutes.

It’s also important to note that goldfish pollute aquariums so much because they don’t have stomachs that breakdown their food. Most of the food simply passes through them and right into your fish tank.

My next section will cover some things to look out for in goldfish poop.

Goldfish Poop – Healthy or Not?

Did you know that you can quickly determine the health of your goldfish just by looking at their poop?

That’s right. Goldfish poop is a pretty good indicator of the health of your fish. Now, to understand when your goldfish poop is a problem, you first must understand what healthy goldfish poop looks like.

Healthy goldfish poop has the following two characteristics:

  • Pellet poop. The poop should not be stringy or runny – small pellets are an indicator of a healthy fish.
  • Dark colored. The exact color will vary depending on the color of the food, but it should always be dark.

Goldfish Has Long and Thick Poop

The most common issue you will probably see with your goldfish is long, thick poop. Obviously, this type of poop is not the pellets that goldfish are supposed to poop out, so it’s a problem.

Long, thick poop like this is normally an indicator that your goldfish is at least partially constipated.

I recommend feeding goldfish peas without shells if you notice long and thick poop. The added fiber should help push things out nicely.

Goldfish Has Dark Cloud Behind It

Sometimes you may notice that your goldfish has a dark cloud behind it. It will almost look like an aquatic version of Pig Pen from Charlie Brown.

Well, your goldfish isn’t Pig Pen. A dark cloud behind your goldfish is a good indicator that your goldfish has diarrhea. The diarrhea leaks out the vent and will form a brown cloud behind your goldfish.

Air Bubbles in Goldfish Poop

Air bubbles in goldfish poop usually mean that your goldfish isn’t getting enough oxygen through their gills. The bubbles form in the poop because the goldfish go to the surface to swallow air.

The best way to fix this problem is to lower the temperature of the tank, increase surface agitation, increase the surface area of the tank, and remove any excess fish from the tank.

Adding an air stone also works, but that’s more of a quick fix that doesn’t solve the actual problem.

Goldfish Has White Poop

If your goldfish has white poop, then that is usually a sign that it has a poor diet. White poop may also indicate a bacterial infection or parasitic infection.

However, in my experience, white poop is almost always just from an improper diet. I recommend feeding your goldfish a mix of vegetables, live worms, and goldfish flakes to prevent white poop.

If you do that and your goldfish still has white poop, then add some antibiotics to the tank if the white poop continues after a few days.

Goldfish Has Clear Poop

Clear poop is different than white poop because, well, it’s clear.

Clear poop in a goldfish means it is malnourished or underfed. Increase the amount of protein and fat you feed your goldfish. Also, stop feeding your goldfish processed food – clear poop is usually an indicator that the goldfish has eaten some processed human food recently.

Do Goldfish Eat Their Own Poop?

No. Goldfish don’t eat their own poop like tilapia. In the case of goldfish, there really isn’t that much nutritional value in the poop, so they have no interest in eating it.

I’ll even go a step further and say that I have personally seen a goldfish eat its own poop and then immediately spit it out. With that experience noted, I will say that it is extremely rare for a goldfish to eat its own poop.

If you do see a goldfish eating its own poop, then feed it. Something is most definitely wrong with the goldfish if it has chosen to eat its own poop.

Final Thoughts

Wow, that article became quite the comprehensive guide to goldfish poop.

To summarize, goldfish do poop. I’m sure anyone that has owned a goldfish is aware of just how much a goldfish poops.. It seems like all a goldfish does is poop.

However, for all the pooping a goldfish does, goldfish don’t actually pee. They do release ammonia and nitrates through their gills, which does pollute the tank. But that is not peeing in the way that we think of peeing. It’s just releasing ammonia into the water.

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