Algae-Eating Shrimp:
The New Janitorial Crew

(Unedited version)
Originally appeared in the November 2005 issue of
Tropical Fish Hobbyist Magazine

Shrimp are one of the new really hot areas in freshwater aquaria. Many are used for algae control. The popularity of these interesting little invertebrates is bringing new species in to the hobby. Though freshwater shrimp are a relatively new area of aquarium keeping in the United States they have been used in other countries for some time.

Shrimp Biology

Shrimp are crustaceans. These animals have a hard outer shell called an exoskeleton. The most distinguishing features that separate the crustaceans from other Arthropods are the two pair of antennae on their heads and their branched appendages. The larger shrimp (including the ones I'll mention in this months column) crabs, lobsters and crayfish are all decapods, meaning they usually have 10 legs, in 5 pairs. The larger pair of legs that develop into pinchers are called chelipeds. There are approximately 45,000 species of Crustaceans, most of which live in the oceans. Other crustaceans include the isopods, like sow bugs and copepods which include much of the oceanic plankton.

The shrimp used for algae eating in the aquarium are small freshwater shrimp. With all aquarium animals consider the size of the shrimp, and the size and temperament of its proposed tank mates before including them in your aquarium. Large aggressive fish will consider your new shrimp as a lovely appetizer.

Be sure your shrimp have food. If they have eaten all the algae in your tank or you have types of algae that the species of your shrimp don't eat, then they will need supplemental foods. There are special dry foods for shrimp and crabs in pellet or tablet forms. Many of the algae eating shrimp will also eat blanched zucchini or spinach.

Ghost Shrimp

The shrimp that was first most commonly seen in the hobby in the United States is the simple ghost shrimp. These shrimp are native to portions of the Southern States and of the genus Palaeomonetes. There may be more than one similar species being sold under the name ghost shrimp. They are also sometimes called grass shrimp or glass shrimp. These shrimp were first used as live foods for large fish, and often still are. They are usually very inexpensive particularly when compared to the other shrimp that are now being offered.

After the publication of the very popular and beautiful Nature Aquarium books by Mr. Takashi Amano which illustrated the use of shrimp as an algae control animal, many aquarists in the United States wanted to try shrimp in their tanks too. Ghost shrimp were the only shrimp readily available to us at the time. Several aquarists, including myself decided to see if these inexpensive little shrimp would be effective at controlling algae too, and they are.

Not only do this clear little shrimp eat hair algae they are also very easy to breed in the aquarium. The female carries the eggs and young under her abdomen like crayfish, until they are ready to be released. The young shrimp look like tiny versions of the parents and eat what they parents do. Of course they are small and most fish will regard them as a yummy snack. So if you want the maximum number of young shrimp to survive you should isolate the female. In a heavily planted tank some fry will usually survive. I've had them get to quite large population levels even with fish, in a heavily planted tank.

In addition to eating algae ghost shrimp are great little scavengers and will eat fish food or even dead fish. In fact they will catch and eat live fish if they possibly can. Usually this is not a problem but can be with fry or injured fish. They may also eat some fish eggs.

Remember that these shrimp are usually used as and sold as a feeder food. Because of this and their low price, they don't seem to get much respect in terms of shipping conditions or housing in the pet stores. Once established in an aquarium they seem to be very healthy. But when purchasing them, make sure the shrimp are very clear. If they are milky in color they are sick. I've never seen a milky shrimp recover. Every milky ghost shrimp I've encountered has died. I'm not sure if this is a symptom of bad conditions and stress from shipping and holding in tanks with large numbers of shrimp, or if it's from a disease, or perhaps some combination of the two.

Amano Shrimp

The next shrimp to become reasonably available in the United States was the Amano shrimp, Caridina japonica. These shrimp are harder to find than the ghost shrimp, though many aquarium shops now occasionally carry them. They are pretty easy to obtain through mail order sources on the internet.

The Amano shrimp are known for their algae eating capabilities, but they will also eat fish foods and, like all shrimp, if they have too much access to fish foods, they will not be as affective at getting rid of algae.

Amano shrimp aren't difficult to breed but it's very, very difficult to raise the resulting young. In my living room tank I have a very large female and several smaller males. My female shrimp is often seen carrying eggs, but I've never had any new shrimp show up in the tank. Why? In their native environment the larval shrimp are carried out toward the ocean after being released from the mother. They grow up in brackish or salty waters. There are a few reports of successful raising of the larva if the mother is moved into a separate tank. After releasing the larva the mother must either be removed or the larva must be removed. The larva must them be acclimated to brackish water, where they must also be fed appropriate food. The larva swim head down and don't take on the adult form for a few weeks. Later the small shrimp must then be reintroduced to a fresh water environment.

Red Cherry Shrimp

These tiny shrimp, Neocaridina denticulata sinensis, are quickly becoming big favorites. The color varies depending on the age, sex and condition of the shrimp. In a strange twist in the animal world, where it is usually the male that is more brightly colored, the female red cherry shrimp are the brightest red. These shrimp are reported to be a variety of the Taiwan pale blue shrimp.

The red cherry shrimp breeds easily in the aquarium. Like the ghost shrimp the females carry the eggs and larva until they are miniature versions of the adults and able to fend for themselves, eating the same foods as the adults. In a mixed species aquarium the tiny baby shrimp are very tempting food to many fish. So just like breeding fish, if you want to achieve the highest numbers of surviving offspring they should be bred in a separate species only tank. Fortunately their small size makes this very simple to accomplish.

Speaking of their small size, use common since in choosing tank mates for these shrimp. Only small non-aggressive fish should be included in aquariums that house any of the small varieties of shrimp.

And More Shrimp

Many other interesting types of algae eating shrimp are becoming available. Tiger shrimp which have tiger stripes as their name implies, green shrimp, and the very attractive bumble bee, ninja and crystal red shrimp are all from the genus Caridina, like the Amano shrimp. As is the interesting red nose shrimp. Many of these will breed in the aquarium.

Other shrimp that are sometimes available in a group called longarm shrimp from the genus Macrobrachium. These can be interesting shrimp but aren't really suitable for the community aquarium. They can be more aggressive and can be good hunters happy to have fish for their dinner meal.

Another type of shrimp that's sometimes seen is the filter feeding shrimp. These are often sold as wood, bamboo, Thai or Singapore shrimp. They are very attractive and interesting shrimp. Their front claws have developed to filter small organisms from the water column, and look almost like feathers when extended. Though lovely shrimp they don't help in controlling algae. If kept great care must be exercised in feeding them appropriately.

If you can't find shrimp locally, don't be afraid to order them through mail order or the internet. Most of the animals you see in your local shops got there through the mail either directly to the stores or through an intermediary distributor. With proper shipping techniques these animals will arrive on your doorstep in good health. Just be sure someone will be at the delivery location so the animals won't be sitting in the heat or cold outside your home.

I think you will find algae eating shrimp to be very interesting and helpful additions to your planted aquarium.

Questions or Comments?

If you have questions or Comments about this column, join the Natural Aquariums Forum and post them here.

Welcome to the Jungle | Into The Forest | The Creepy Crawlies | A Clearing in the Thicket | Algae Eaters for the Planted Aquarium
North American Natives | Why things go wrong Pt 1 | Why things go wrong Pt 2 (Algae) | Algae Eating Shrimp | Lo-Tech Tanks
Welcome to the Fish Room | The Stemmed Plants | Mosses | A Livebearer Biotope | Planted Tank Social | The Genus Hygrophila | Cyanobacteria
Easy Plants | What I Did Last Summer | Decorations in the Planted Tank | Botany-An Introduction to Plant Biology | Botany-Anatomy of a plant
Botany-How Plants Work | Easy Rosettes | Going High-Tech | Floating Plants | Dealing with Success | Bringing the Outside In | Vallisneria
Hair Algae | Flowering Aquarium Plants Part 1 | Flowering Aquarium Plants Part 2 | Liverworts in the Aquarium | Elements of Design
Planted Aquarium Maintenance | More Mosses | Invaders | Ferns in the Aquarium | Setting up a Planted Aquarium
Seaweeds of the Pacific Northwest | Proserpinaca | Hardware for the Planted Aquarium | Rotala | Neocaridina Shrimp | Lo-tech Tank Tips

Home | Forum | Articles | Plants | Inverts | Store

Vote for us daily on Aquarank

Search the Natural Aquariums web site

Discover new ways to explore your aquarium hobby every month with "Tropical Fish Hobbyist Magazine". The World's Aquarium Magazine since 1952.

For more information about planted aquariums, Natural Aquariums recommends "The Simple Guide to Planted Aquariums" by Terry Barber and Rhonda Wilson.

Natural Aquariums


Ask questions
Share your successes

"Nature Aquarium World 2" The second Nature Aquarium World book from Takashi Amano. Mr. Amano's aquariums and photography make him the most celebrated planted aquarist in the world today.

Christel Kasselmann's "Aquarium Plants" is the most complete encylopedia of aquarium plants to date. A must have book for the aquatic plant enthusiast.