Do Red Cherry Shrimp Eat Fish Poop?

This question once came up in a shrimp forum I was reading. Someone said cherry shrimp never touch fish droppings. That made me think about what I’d seen in my own tanks. I’ve watched cherry shrimp pick at and around fish waste plenty of times. Working out exactly what they’re taking from it is a different matter.

What you can see from the glass

A cherry shrimp uses its front legs to bring tiny particles to its mouth. You can see the same movement on a leaf, a piece of wood or a bit of debris. Around fish waste there may be microbes, bits of food and other material. Watching a shrimp pick away tells you it’s foraging. It’s hard to tell precisely what it’s eating or how much nutrition it gets from it.

Separate what you saw from what you can conclude

A shrimp’s front legs move so quickly that even a good close-up can leave you guessing. It might be picking at a tiny bit of food beside a dropping, browsing the material that collects on it or taking particles from the surface itself. From the glass, you can usually tell where it’s foraging. You can’t reliably tell which particles it swallowed or whether they made up a useful meal.

That matters because it’s easy to turn a small observation into a rule for the whole aquarium. One person might have watched shrimp walk past fresh waste and another might have seen them gather around older debris. Both could have watched exactly what they describe. There are different surfaces, currents and particles in each tank. The shrimp are exploring what they find, and what they find varies from place to place.

If you want to see the difference for yourself, watch a quiet corner where debris tends to settle and then look at a piece of established wood. You’ll see much the same picking movement on both. Try to notice where the shrimp pause and what else is lying nearby. That’s a more useful observation than trying to decide what each movement means.

Why the waste still matters

The shrimp may move small pieces while they forage. That can make a patch look tidier for a while, and it can also push material deeper into gravel or into a sheltered pocket. Take a look during your next routine water change. Clear accumulated material you can reach and check whether there’s a reason it keeps ending up there.

Where food is going in matters too. If fish miss part of a feed and those pieces settle in the same corner, watch the next feed and see what reaches the bottom. You might find that some food is getting into places where neither fish nor shrimp can use it. Putting portions where you can check them makes it easier to adjust what you give and clean up afterwards.

Keep the normal feeding and cleaning routine

If you see shrimp working over a dropping, you can carry on with the same routine. Leave established grazing surfaces where practical, offer a suitable prepared food in amounts the colony can use, and siphon accumulated waste during maintenance. In a community tank, watch whether the shrimp can reach the food before the fish do.

If debris is building up in a corner, look at what lands there and how often you can get to it. The shrimp might spend a lot of time in that corner, and you can still clear the build-up during your next appropriate water change.

For a prepared food you can place and observe, have a look at Spirulina Complete. If you want to know what else shrimp pick at around the tank, read the guide to grazing and aquarium clean-up.

Give shrimp in a community tank an observable meal

If you want to know whether the shrimp have access to prepared food, put a small sinking portion near a route they already use. A flat stone next to cover lets you see the food from the side and gives smaller shrimp a shorter distance to cross. Feed the fish their normal amount and watch what happens when the shrimp’s portion goes down.

A fish may arrive first and carry off the food. A snail may sit on it, leaving space for the shrimp to graze from the edges. If you want a clearer picture, check more than once. Watch the first few minutes, then take a look later when the room is quiet. The food remaining in the original spot tells only part of the story.

Keep useful grazing surfaces while you clean

There’s room to leave a little growth on the back glass or established wood while clearing loose debris from the bottom. The shrimp may carry on grazing as soon as you’re finished. If you keep finding an area full of waste, make it easier to reach with the siphon rather than leaving it in the hope the shrimp will deal with it over time.

Keep your ordinary tests going and look at the filter if water quality changes. An animal picking at a bit of debris can be behaving normally while the tank still needs maintenance. If you find yourself looking for more ways to judge whether the colony has enough to eat, the guide to feeding shrimp in a tank with algae gives you a practical way to make that decision.

The next time you see a shrimp stop at a dropping, enjoy watching what it does. It gives you a little window into how it forages. Keep the normal feeding and cleaning routine, and give the colony a feeding spot you can see when it’s time to offer prepared food.

What to look at during a water change

If a patch of debris disappears when you move a plant, see where it lands before you finish. A narrow siphon can help you reach around the outside of cover. Keep an eye out for small shrimp before starting. It’s easier to remove what you can see in a quiet corner than to stir everything up and try to catch it later.