What do shrimp eat? Their natural diet, and how to copy it in a tank
Watch a cherry shrimp for a minute and you'll see it picking at everything: glass, leaves, rocks, moss, the substrate. That constant grazing is the clue to what shrimp actually eat. Prepared shrimp food matters, but in a healthy tank it is the smaller part of the diet. This guide covers what dwarf shrimp eat in nature and how to use that to keep them well fed. For specific products, see best shrimp food.
What shrimp eat in the wild
| Food | What it is | In your tank |
|---|---|---|
| Biofilm | A slimy film of microalgae, diatoms, bacteria, fungi and single-celled organisms on rocks, wood, leaves and glass | Grows on every surface in a mature tank; more surface area (moss, wood, rock, leaves) means more grazing |
| Soft algae | Green film and other soft algae on surfaces | Shrimp graze it, but they won't clear a real algae outbreak; see algae in a shrimp tank |
| Leaf litter | Fallen leaves breaking down in the water, plus the biofilm growing on them | Dried leaves sold for aquariums, such as catappa (Indian almond) or oak; they soften and grow biofilm |
| Detritus | Fine bits of decaying plant and animal matter | Shrimp sift it from the substrate and moss |
| Tiny animals | Meiofauna such as nematodes, rotifers, small worms and microcrustaceans | Present in most established tanks; shrimp eat some of them |
| Dead animals | Dead fish, snails and other shrimp | Shrimp scavenge them; remove large dead animals before they foul the water |
What the research says
- They eat almost anything available. The U.S. Geological Survey's species profile describes Neocaridina davidi as an opportunistic omnivore that feeds on detritus, algae and tiny animals such as oligochaete worms, microcrustaceans and nematodes. A University of Florida IFAS profile says they graze algae, biofilms and dead plants and animals, and spend most of their time grazing biofilm on leaf litter.
- Leaf litter is a real food source. In a study in the journal Crustaceana, researchers offered cherry shrimp from a wild population in Germany four kinds of decaying tree leaves. Adults preferred alder and poplar, juveniles weren't picky, and the shrimp ate a large share of their body weight in leaf litter each day, much of it along with the biofilm growing on the leaves.
- Biofilm alone can sustain them. A study in Aquaculture Research raised cherry shrimp with biofilm, mostly microalgae, diatoms, cyanobacteria and ciliates, as their only food. The shrimp survived, grew, matured and carried eggs, which suggests a tank rich in biofilm can carry much of a colony's diet.
- They hunt tiny prey. In a microcosm study in Limnologica, stomach contents showed cherry shrimp regularly eating meiofauna, and the shrimp reduced the numbers of nematodes, microcrustaceans and small worms over six weeks.
The takeaway: shrimp evolved to graze constantly on a mix of tiny foods. A big pile of pellets once a day is the opposite of how they eat, which is why overfeeding is such a common problem.
Do shrimp eat plants?
Dwarf shrimp mostly pick at the film on plant leaves and at leaves that are already melting or decaying, not at healthy growth. If shrimp seem to be eating a plant, look closely: the leaf is usually dying already, or the shrimp are grazing biofilm and algae on it. Owners occasionally report hungry shrimp nibbling very soft new growth, which is a sign to check that the colony is getting enough to eat. See best plants for a shrimp tank.
Do shrimp eat fish, snails or baby shrimp?
Dwarf shrimp are scavengers, not hunters of anything bigger than microscopic prey. They will swarm a dead fish, snail or shrimp, which can look alarming but usually means the animal was already dead or dying. Healthy fish and snails aren't on the menu. Remove large dead animals promptly so they don't add ammonia; see ammonia and nitrite in a shrimp tank.
Do shrimp eat their molts?
Often, yes. Shrimp commonly pick at their shed exoskeletons over a few days, and many keepers leave molts in the tank for that reason. A molt is not a dead shrimp; see how often do shrimp molt.
What baby shrimp eat
Shrimplets eat the same things as adults in smaller pieces, and they depend even more on biofilm because they can't push past adults to reach pellets. A mature tank with moss, leaves and plenty of surface area is the best baby food. Powdered foods and biofilm boosters help in newer tanks. See how to breed cherry shrimp.
How to feed a shrimp tank around their natural diet
- Let the tank mature. Many keepers wait a few weeks after the cycle finishes so biofilm and algae can build up before adding shrimp. See how to cycle a shrimp tank.
- Add grazing surfaces. Moss, driftwood, rocks and fine-leaved plants all grow biofilm.
- Keep some leaf litter. A leaf or two of an aquarium-sold dried leaf gives shrimp something to graze between feedings; replace it when it falls apart.
- Feed small amounts of prepared food. Give an amount they finish in a few hours, a few times a week. A blanched vegetable now and then adds variety. See best shrimp food.
- Remove leftovers. Uneaten food breaks down into ammonia, and shrimp are very sensitive to it.
- Don't panic about a missed feeding. An established tank keeps feeding them; see how long can shrimp go without food.
Track it
Note feeding days and any leftovers on the free Water Parameter Log printable next to your GH, KH, TDS and temperature readings. If ammonia or algae ever creeps up, you'll be able to see whether feeding changed first.
Frequently asked questions
What do cherry shrimp eat naturally?
Biofilm, soft algae, decaying leaves and plant matter, detritus, and tiny animals such as nematodes and microcrustaceans, plus dead animals they find. Research describes them as opportunistic omnivores.
Can shrimp live on biofilm alone?
In a well-established tank, biofilm and algae can carry much of their diet, and one study raised cherry shrimp on biofilm as their only food. Most keepers still add small amounts of prepared food, especially in newer tanks.
Do shrimp eat live plants?
Mostly not. They graze the film on leaves and eat leaves that are already decaying. Healthy plants are usually left alone.
Do shrimp eat fish poop?
They eat detritus, which includes some broken-down waste, but they are not a substitute for water changes and filtration.
Will shrimp eat dead fish?
Yes. Shrimp scavenge dead fish, snails and shrimp. Remove large dead animals promptly so they don't foul the water.
What should I feed shrimp besides shrimp food?
Leaf litter sold for aquariums and the occasional blanched vegetable. In a mature tank, biofilm and algae fill in between feedings.
Sources: U.S. Geological Survey, Nonindigenous Aquatic Species: cherry shrimp (Neocaridina davidi) (opportunistic omnivore feeding on detritus, algae and meiofauna); Suen and Gillett-Kaufman, Cherry Shrimp Neocaridina davidi (UF/IFAS EDIS IN1301) (grazes algae, biofilms and dead plants and animals; most time spent grazing biofilm on leaf litter); Schoolmann and Arndt, Leaf-litter preferences of the introduced freshwater shrimps Atyaephyra desmarestii and Neocaridina davidi, Crustaceana (leaf-litter preferences and consumption rates); Breeding and life cycle of the ornamental freshwater shrimp Neocaridina davidi in a biofilm-based culture system, Aquaculture Research (biofilm as the sole diet supported growth and reproduction); Weber and Traunspurger, Influence of the ornamental red cherry shrimp Neocaridina davidi on freshwater meiofaunal assemblages, Limnologica (stomach contents show frequent meiofauna consumption); Shrimp Tank Hub's food and feeding guides.