What do shrimp eat when nobody feeds them?
Most of what a freshwater shrimp eats is invisible, and it is not food anybody buys. It is biofilm, and in an established tank it is on every surface the animal touches. Everything else on this page is a supplement to that.
Aquatic Arts defines it: biofilm is a thin layer of microorganisms, composed of bacteria, fungi, algae, and protozoa, that forms on any submerged surface in an aquarium. It names the animals that live off it and three of them are records here: shrimp, nerite snails, and otocinclus catfish.
Aquarium Co-Op describes the same diet from the other end: dwarf shrimp are last on the food chain, serving as scavengers that eat decaying plants, deceased animals, algae, and biofilm chock-full of microorganisms. It sums the diet up in one line: their diet consists of both proteins and vegetable matter.
The timing matters for anybody setting up a tank. Aquatic Arts: biofilm typically begins to form within a few days to a few weeks, depending on the conditions of the aquarium. It grows on driftwood, rocks, live plants, especially mosses like java moss, and on botanicals such as Indian almond leaves and alder cones.
That list is the reason our java moss record keeps turning up on shrimp pages, and it is the cheapest thing on this page: a surface, some light, and a few weeks. Aquatic Arts calls biofilm a natural food source and names it a primary one for shrimp, which is worth holding onto before reading any food list: the natural diet is not something a keeper buys.
What this guide is
- The question
- Six thousand seven hundred searches a month, and the answers are food lists. The food list is the smallest part of the answer.
- The records behind it
- Our cherry shrimp, amano shrimp and ghost shrimp records, and the sources on each.
- What it will not do
- Give you a schedule or a portion. Station 08 is about why not one of our sources publishes either.
| Surface | What our sources say about it | Written here |
|---|---|---|
| Driftwood | Named by Aquatic Arts as a surface that supports biofilm development, and recommended for that reason | Asked for on our cherry shrimp and kuhli loach records |
| Rocks and hardscape | Named the same way. Our siamese algae eater record adds the wild version, a stream bed of boulders, pebbles, gravel and sand carrying biofilm | Asked for on the siamese algae eater record |
| Mosses | Aquatic Arts names java moss and subwassertang specifically as biofilm surfaces | Our java moss record |
| Botanicals: leaves and cones | Indian almond leaves and alder cones, named by Aquatic Arts as boosting biofilm development | no record here yet |
| Any other submerged surface | Aquatic Arts: biofilm forms on any submerged surface in an aquarium, within a few days to a few weeks | Every tank on this site |
Read that table as a shopping list and it is cheaper than the food list in station 04. Leaves, wood and moss are what a freshwater shrimp grazes between feedings, and the guides that answer this question with a food packet skip the part that feeds the animal for the rest of the week.
Three shrimp records, three diets, one shape
This site holds three shrimp records and each one carries a diet field taken from its own sources. Put side by side they describe one animal doing one job.
| Record | What the row says | The qualification its sources attach |
|---|---|---|
| Cherry shrimp | Algae, biofilm and detritus | Wikipedia adds that they do not eat vascular plants. Aquarium Co-Op adds crushed coral for the calcium a continuously molting animal needs |
| Amano shrimp | Algae, and it prefers not to be | Aquarium Co-Op: they will go after hair algae, thread algae and even black beard algae, but are not as good at eating flat types that grow on surfaces, and they prefer not to eat algae if other tastier options are available |
| Ghost shrimp | Omnivore and scavenger | Aquarium Care Basics: algae, dead plant matter and detritus, and they love fish or shrimp pellets, flakes, algae wafers or any otherwise uneaten food |
Read down the middle column and the answer to what do shrimp eat is already there: algae, biofilm, detritus, and whatever else the tank has going spare, grazed off surfaces rather than eaten from a dish. Read down the right column and the useful half appears, which is that every source qualifies its own answer.
One qualification is worth pulling out because it changes what a keeper should do. Our amano shrimp record carries Aquarium Co-Op saying that feedings should be limited for a few days if you want them to work on an algae problem. Station 03 is what follows from that.
Feed them well and they stop doing the job you bought them for
Nobody buys a shrimp for its personality either. The reason a cherry shrimp or an amano goes into a tank is almost always algae, and the sources on our own records say something about that which no feeding guide we read repeats.
- Aquarium Co-Op, on the amano shrimp: they prefer not to eat algae if other tastier options are available, so feedings should be limited for a few days if you want them to work on an algae problem.
- Aquarium Co-Op, on the same animal: they will go after hair algae, thread algae and even black beard algae, but are not as good at eating flat types of algae that grow on surfaces.
- Aquarium Co-Op, on shrimp generally: their diet consists of both proteins and vegetable matter, and it names six commercial foods to provide it.
Those three statements are from the same publisher and they pull in two directions. A well fed shrimp is a healthy shrimp and a worse algae eater. That is not a contradiction to be resolved; it is a choice a keeper makes, and it should be made deliberately rather than by accident.
The same shape appears on two other records here. Our siamese algae eater record carries Aquarium Co-Op saying that as adults, their hefty size lets them get the lion’s share of the fish food, so they are less likely to graze on algae. Our otocinclus and bristlenose pleco records both carry a source saying algae alone will not feed the fish.
So across four records the same sentence keeps arriving in different words: an algae eater fed properly eats less algae, and an algae eater left to the algae is not fed properly. Our water and health page is where this site keeps the algae claims from every record in one place.
What to put in the tank, and how our sources say to prepare it
The commercial half
Aquarium Co-Op names six products rather than describing a category: Hikari Shrimp Cuisine, Hikari Crab Cuisine, Xtreme Shrimpee Sinking Sticks, Repashy Soilent Green, Repashy Community Plus and Zoo Med Nano Banquet Food Blocks. It also names the protein side of the diet plainly: krill and squid.
Two things on that list are worth reading rather than buying. One is that the same source says the food should be tiny enough to be eaten by both babies and adults, and the other is what it says about calcium: these foods are there to provide the essential nutrients a shrimp cannot graze, in its own words calcium and other vitamins to promote healthy molting and growth, which is station 05.
The vegetable half
Aquarium Co-Op names canned green beans, canned sliced carrots and blanched slices of zucchini. Aquarium Breeder gives the full method and the reason for it.
Blanching, per the source that publishes the method
- Why: blanching means that we will soften them up, so it will be easier for the fish, shrimp or snail to eat them. It also makes the piece sink instead of float, and a soft piece is one a shrimp can graze for days.
- Wash and peel first: clean it under tap water, and the same source recommends peeling to remove potential pesticide residues.
- How long: the blanching process usually takes 1 or 3 minutes, then straight into an ice bath to stop the cooking. In a microwave, 15 or 30 seconds will be enough.
- What to use: zucchini, cucumber, lima beans, carrots, broccoli, lettuce and cabbage.
- What not to use: fruit, because the sugar can cloud your water and cause bacterial blooms.
- When to take it out: it is advisable to remove any uneaten portions after 24 hours.
That last line is the only number on this page that behaves like a rule, and Aquarium Co-Op agrees with it from the other direction: uneaten vegetables will fall apart eventually and may cause water quality issues.
| Named food | Named by | What the source says it is for |
|---|---|---|
| Hikari Shrimp Cuisine | Aquarium Co-Op | A prepared shrimp food, tiny enough to be eaten by both babies and adults |
| Hikari Crab Cuisine | Aquarium Co-Op, and Aquarium Breeder | Named by Aquarium Co-Op as a shrimp food and by Aquarium Breeder among the calcium sources |
| Xtreme Shrimpee Sinking Sticks | Aquarium Co-Op | A sinking stick, so the food reaches the animals that never leave the substrate |
| Repashy Soilent Green | Aquarium Co-Op | The vegetable half of the diet in gel form |
| Repashy Community Plus | Aquarium Co-Op | The protein half, alongside krill and squid on the same page |
| Zoo Med Nano Banquet Food Blocks | Aquarium Co-Op | A block rather than a portion, which is the nearest thing on this page to a schedule |
| Mineral blocks and Wonder Shells | Aquarium Breeder | Calcium and minerals rather than food, for the molting in station 05 |
The half of the diet that is not food
A shrimp does not grow steadily. It grows by throwing away its shell and building a new one, and the material for that comes out of the water and the food together.
Aquarium Breeder gives the figure: about 30 to 50 percent of shrimp shells is calcium carbonate. For comparison, on the same page, about 95 to 98 percent of a snail shell’s dry weight is calcium carbonate, which is the chemistry our nerite snail and assassin snail records carry.
And the frequency, which is what makes it a diet question rather than a water question: baby shrimp molt every few days and adults monthly, per the same source, so the demand never stops.
Where our sources say it comes from
- The water. Aquarium Breeder puts remineralizers first for anybody using RO water, and mentions maintaining a 3:1 calcium to magnesium ratio.
- Supplements. The same source names eggshell powder, cuttlebone, mineral blocks, Wonder Shells and commercial products including Hikari Crab Cuisine, which is also on Aquarium Co-Op’s food list.
- Vegetables. It publishes the calcium content of four: kale at 137 mg per 100 g, spinach at 99, Chinese cabbage at 74 and broccoli at 40.
- Crushed coral, which our own cherry shrimp record carries from Aquarium Co-Op for exactly this reason.
Nobody publishes a dose. Aquarium Breeder recommends testing water parameters weekly, adding a pinch periodically and adjusting to how the animals respond, and it warns that excess is possible. That is as close to a number as this page gets, and it is not one.
Four questions our sources do not answer
The searches around this one are specific, and the honest thing to do with a specific question no source we hold addresses is to say so and print what they do say instead.
Do shrimp eat fish poop?
Not one of our sources says they do. What they describe is close enough to explain where the idea comes from and different enough to matter. Aquarium Co-Op: scavengers that eat decaying plants, deceased animals, algae, and biofilm. Aquatic Arts: biofilm forms on any submerged surface. Our ghost shrimp record carries detritus, which is decaying organic matter rather than waste as such. A shrimp picking at something on the substrate is picking at the biofilm growing on it, which is the reading our sources support and not the same claim as the one in the question.
Do shrimp eat snail poop?
The same answer and the same silence. No source we hold names it. Our snails silo and our what to feed a snail guide describe animals that produce a great deal of waste and eat a great deal of biofilm, and neither of them makes the claim either.
Do shrimp eat other shrimp?
Aquarium Co-Op comes closest with deceased animals on the scavenging list, which includes a dead shrimp. No source we hold describes a healthy shrimp being attacked by another, and our three shrimp records say nothing about it either. A shell left after a molt is not a dead shrimp, and every source on our records describes an animal that eats what is already lying there.
Do shrimp eat brine shrimp?
Nobody says. Aquarium Co-Op names krill and squid as the protein half of a shrimp diet, and brine shrimp appear all over this site as food for fish: our brine shrimp guide exists because fry need them. For shrimp themselves the protein comes from the products and the scavenging, per every source we hold.
What baby shrimp eat, and why it is not the same question
Two of our sources treat the young as a separate feeding problem and both give the same answer.
Aquatic Arts: biofilm is especially critical for shrimp fry, providing the proteins and fatty acids needed for growth and development.
Aquarium Co-Op is practical about it: it asks for powder food put directly into the water column for the baby shrimp to eat, since newborns do not swim around a lot and cannot compete with adults.
Put those together and a tank that can raise shrimp is a tank with surfaces rather than a tank with food in it. That is the same conclusion our cherry shrimp record reaches from the breeding end, where a colony needs cover and time rather than a feeding regime.
The molting clause, which is a feeding problem too
Baby shrimp molt every few days, per Aquarium Breeder, which is why station 05 matters more for a breeding tank than for a display tank.
It is also the reason a shrimp colony is vulnerable in a way the adults are not. Our assassin snail record carries three sources saying that animal takes weak, sick or molting shrimp and shrimp fry, while healthy adults are safe. Our betta record carries Aquarium Co-Op saying bettas are notorious for going after shrimp.
A feeding guide cannot separate itself from that: the shrimp most in need of food are the ones least able to reach it and most likely to be eaten.
What none of our sources will tell you
How often to feed, and how much supplemental food
Aquarium Co-Op publishes no feeding frequency at all on its shrimp food page, and no quantity of supplemental food either. Aquarium Breeder publishes none for calcium either, recommending a pinch periodically and adjusting. Our three shrimp records carry no schedule between them, and our ghost shrimp record says so outright: no source states a feeding frequency.
How much
Nobody publishes a portion. The only quantity rule anywhere in our sources is the negative one: remove uneaten vegetables after 24 hours, per Aquarium Breeder, because uneaten food causes water quality issues, per Aquarium Co-Op.
Overfeeding, which is the only failure our sources name
Neither source publishes a portion, and both publish the consequence of getting it wrong in the same direction. Aquarium Breeder: it is advisable to remove any uneaten portions after 24 hours. Aquarium Co-Op: uneaten vegetables will fall apart eventually and may cause water quality issues. Overfeeding a shrimp tank is a water quality problem before it is a shrimp problem, and it is the one thing on this page every source agrees about.
Why the silence is reasonable
A schedule assumes the tank is empty of food, and an established shrimp tank never is. Every source on this page describes freshwater shrimp grazing biofilm continuously off every surface, taking the nutrients they need from a natural food source rather than from a portion, which is a supply no keeper can measure and no publisher can convert into a portion.
Our what to feed a snail guide ran into exactly the same wall, with five sources and no schedule between them, and reached the same place: the feeding question for a scavenger is really a question about how established the tank is.
What this guide will say, as ours rather than as anybody’s figure: a tank young enough to need a feeding schedule is a tank too young for shrimp.
Shrimp feeding questions, answered from the sources
What do shrimp eat in an aquarium?
Biofilm first, then algae, detritus and decaying plant matter. Aquarium Co-Op describes dwarf shrimp as scavengers that eat decaying plants, deceased animals, algae, and biofilm chock-full of microorganisms, and says the diet consists of both proteins and vegetable matter. Aquatic Arts calls biofilm a primary food source. Our three shrimp records carry the same answer in three different wordings.
What do cherry shrimp eat?
The same three things every freshwater shrimp species on this site eats, and our cherry shrimp record prints them as one row: algae, biofilm and detritus. Its sources add two details the other records do not. Wikipedia says they do not eat vascular plants, so a planted tank is safe. Aquarium Co-Op adds crushed coral, for the calcium a continuously molting animal needs. What do cherry shrimp eat as a supplement is answered by the food table in station 04, and how often is answered in station 08: nobody publishes a schedule.
What is biofilm and why does it matter?
Aquatic Arts: a thin layer of microorganisms, composed of bacteria, fungi, algae, and protozoa, that forms on any submerged surface in an aquarium. It begins to form within a few days to a few weeks depending on conditions, and it grows on driftwood, rocks, live plants, especially mosses like java moss, and on botanicals such as Indian almond leaves and alder cones. For shrimp fry the same source calls it especially critical.
Do I need to feed shrimp at all?
In an established tank, less than most food lists imply, and there is a reason to hold back. Our amano shrimp record carries Aquarium Co-Op saying they prefer not to eat algae if other tastier options are available, so feedings should be limited for a few days if you want them to work on an algae problem. In a new tank the opposite applies, because the biofilm is not there yet.
What vegetables can shrimp eat?
Aquarium Breeder names zucchini, cucumber, lima beans, carrots, broccoli, lettuce and cabbage, and warns against fruit because the sugar can cloud your water and cause bacterial blooms. Aquarium Co-Op names canned green beans, canned sliced carrots and blanched zucchini.
How do you blanch vegetables for shrimp?
Aquarium Breeder publishes the method: wash under tap water and peel to remove potential pesticide residues, boil for 1 to 3 minutes or microwave for 15 to 30 seconds, then move the pieces straight into an ice bath. The point is to soften them so they are easier to eat and so they sink. Remove any uneaten portions after 24 hours.
Why do shrimp need calcium?
Because they rebuild a shell repeatedly. Aquarium Breeder: about 30 to 50 percent of shrimp shells is calcium carbonate, baby shrimp molt every few days and adults monthly. It names eggshell powder, cuttlebone, mineral blocks, Wonder Shells and commercial foods as sources, and publishes the calcium content of four vegetables, with kale highest at 137 mg per 100 g. Our cherry shrimp record carries crushed coral from Aquarium Co-Op for the same reason.
Do shrimp eat fish poop?
No source we hold says so. What they describe is a scavenger eating decaying plants, deceased animals, algae, detritus and biofilm, and biofilm forms on every submerged surface. A shrimp working over something on the substrate is grazing what grows on it, which is not the same claim.
Do shrimp eat other shrimp?
Aquarium Co-Op lists deceased animals among the things dwarf shrimp scavenge, which includes a dead shrimp. No source we hold describes a healthy shrimp being attacked by another, and our three shrimp records say nothing about it.
What do baby shrimp eat?
Biofilm, and powder food if you are helping them. Aquatic Arts calls biofilm especially critical for shrimp fry, providing proteins and fatty acids for growth. Aquarium Co-Op asks for powder food put directly into the water column, since newborns do not swim around a lot and cannot compete with adults.
How often should shrimp be fed?
No source we compile from publishes a frequency, and our ghost shrimp record says so on the record. The only timing rule anybody gives is when to take food out: after 24 hours, per Aquarium Breeder, because uneaten food degrades water quality, per Aquarium Co-Op.
Can shrimp live on algae alone?
Our sources describe a diet of both proteins and vegetable matter, so algae alone is not what any of them recommends. The same warning appears on two fish records here: our otocinclus and bristlenose pleco records both carry a source saying algae alone will not feed the fish.
What eats shrimp in a community tank?
More than a feeding guide would like. Our betta record carries Aquarium Co-Op saying bettas are notorious for going after shrimp. Our assassin snail record carries three sources saying it takes weak, sick or molting shrimp and shrimp fry. Our african dwarf frog record carries a source saying dwarf frogs will eat all your dwarf shrimp. The tank mates grid prints each of those with the reason attached.