Do Fish Eat Poop? Exploring the Complex Truth Behind Coprophagia in Aquarium Fish

As an aquarium hobbyist, you’ve likely noticed fish poop accumulating in the gravel and wondered if your fish eat it. The idea of fish intentionally consuming waste may seem off-putting. However the truth behind coprophagia (poop eating) in fish is more nuanced.

While fish don’t purposefully eat poop as a regular part of their diet, some species do exhibit occasional coprophagic behaviors. Understanding the misconceptions, motivations, and risks related to poop eating in fish will help you maintain a healthy tank environment.

Common Poop Eating Fish Species

Though not all aquarium fish eat poop, some well-known types are prone to coprophagia including:

• Plecos – With their sucker mouth designed to graze algae off surfaces, plecos invariably suck up poop too

• Corydoras – These active bottom feeders forage for food across the substrate, where poop collects.

• Goldfish – When hungry, goldfish will eat anything they can fit in their mouth, including waste.

• Mollies – Mollies will snap up poop as it drifts down before it settles on the gravel.

• Cichlids – Underfed cichlids survive by eating decaying matter like poop and even resort to cannibalism.

• Rabbitfish – Wild rabbitfish are known to consume poop to supplement their diet, a behavior that may translate to tanks.

Misconception #1: Poop Is a Dietary Staple

The first myth to dispel is that poop comprises a meaningful part of any fish’s diet. No fish species primarily eats poop as a food source.

Rather, most poop consumption is incidental. Fish with mouth shapes and feeding behaviors prone to picking up debris off the tank floor also suck up poop accidentally.

In other cases, fish may deliberately target poop due to hunger or curiosity but will nearly always spit it back out after tasting it. They gain minimal to no nutritional value from poop.

Misconception #2: Poop Eaters Clean Your Tank

Another common misconception is that poop eating fish eliminate the need for gravel vacuuming and filter cleaning. This is false. Even dedicated poop eating fish can only consume a small fraction of waste.

Expecting these fish to control poop is unrealistic. Their capacity is limited, and they themselves contribute to waste. Relying on them leads to hazardous ammonia spikes. Regular mechanical cleaning is still essential.

Why Do Fish Sometimes Eat Poop?

If poop isn’t actually food, why do some fish actively seek it out? There are a few primary reasons:

• Hunger – When deprived of other food sources, fish may turn to poop in desperation.

• Instinct – Some bottom feeders evolved eating all debris in their environment, even if offers minimal nutrition.

• Curiosity – Young fish often explore new objects like poop through their mouths as a form of investigation.

• Confusion – Fish with poor eyesight can mistake poop particles for regular food floating in the tank.

In all cases, poop consumption is driven by factors other than nutritional value, since poop contains little usable energy or biomass.

Health Risks of Coprophagia in Fish

While occasional accidental poop eating is usually benign, chronic poop consumption poses some health hazards to fish:

• Toxicity – Poop contains metabolic waste products that can poison fish in large doses.

• Parasites – Parasite eggs and protozoa in poop can infect the gastrointestinal tract.

• Bacteria – Consuming poop exposes fish to harmful pathogens that cause disease.

• Blockages – Compacted poop can obstruct delicate digestive systems not adapted to process it.

• Organ damage – Indigestible matter in poop may irritate and erode intestinal linings.

To avoid these outcomes, address the root triggers that cause fish to eat poop through proper feeding, tank maintenance, and addressing stressors.

Strategies to Limit Poop Eating

If your fish engage in frequent poop eating, there are some tank management steps you can take to curb this behavior:

• Feed a balanced, high quality diet to discourage poop consumption driven by hunger.

• Perform regular gravel cleaning to remove accumulated poop so it is not available to eat.

• Use additional filtration and water changes to eliminate ammonia from decomposing poop.

• Provide ample tank space and shelters so territorial fish do not feel stressed.

• Introduce clean up crew animals like snails and shrimp that compete to eat poop.

-Redirect fish away from poop piles using decor or target feeding in other areas.

The Complex Reality of Fish Coprophagia

Hopefully this breakdown has revealed the nuances surrounding poop eating in aquarium fish. While a normal behavior for some species, it should not be encouraged or relied upon.

Rather than reviling poop eaters, understand the eating of waste results from fish behavior and tank conditions. Careful aquarium management can minimize coprophagic tendencies and promote healthier fish.

The next time you see your fish suck up some poop, don’t panic. Use it as a reminder to feed, clean, and inspect water parameters. A balanced tank ecosystem will limit interest in poop without you needing to obsess over waste.

With some patience, observation, and diligent tank maintenance, your fish will fulfill their roles as peaceful pets rather than putrid poop processors! Let their natural behaviors guide you towards becoming a more conscientious aquarist.