The Basics of Keeping Fresh Water Invertebrates

It’s often thought that aquarium enthusiasts do not have much to choose from when it comes to fresh water invertebrates, but this really isn’t so. Even when compared to the richness of the sea, there are still many possibilities for fresh water aquariums.

Generally, there are two types of invertebrates that aquarium keepers can choose from, yet within these two choices we can find a surprisingly large variety of creatures that are suitable for living in an aquarium environment. The two choices on offer are mollusks and crustaceans. On the whole, these animals are usually very undemanding, hardy, and therefore pretty easy to keep.

Problems With Fresh Water Invertebrates

But this doesn’t mean there aren’t some difficulties involved with fresh water invertebrates - they certainly require proper care if they are going to lead healthy, fulfilling lives in your aquarium.

The first challenge with lots of types of invertebrates is that many of them are not compatible with the kinds of tropical fish we like to keep in our aquariums. Many fresh water invertebrates need a combination of brackish water and cool temperatures, which is damaging for many of our favorite fish. Another consideration is that lots of types of invertebrates require some kind of land to walk around on.

Anotherchallenge for fresh water invertebrates is their feeding habits often present an issue for aquarists. Many types of invertebrates need to eat living plants, others like to eat fish, and yet more exist primarily as filter feeders – which are almost impossible to feed.

A third, more manageable problem is that some types of invertebrates like to multiply at terrific rates, quickly becoming more pests than pleasures to keep in our aquariums.

Pets or Pests?

Fresh water invertebrates can in fact make excellent pets to keep in our aquariums. They are often fascinating to observe, yet we need to be very careful about which ones we choose. The main point is to avoid impulse buying of different types of invertebrates without doing your research first. Many fresh water invertebrates totally unsuited to life in a fresh water aquarium and will quickly die. Even those that are suitable for aquarium life need a lot of care and attention.

So which invertebrates are suitable for your fresh water aquarium? Let’s take a look at some of the most commonly kept invertebrates.

Types of Invertebrates Suitable for Aquarium Life




Algae Shrimp

Peaceful creatures, consume algae, flake etc.

Eaten by larger fish.

Apple Snails

Beautiful, easy to find and fun to watch

Can damage aquarium plants, short lifespan in aquariums.

Clams & Mussels

Always an interesting addition!

Require cool water and filter feeder food, are often nibbled by fish, like to burrow out of sight.


Fun novelty creatures to add to your aquarium, very active.

Need brackish water, dry land, can be predatory.


Attractive, brightly colored shades of red or blue.

Can be predatory and territorial, will fight each other, nocturnal.

Fan Shrimp

Large size makes them very interesting to observe.

Territorial, sensitive to poor quality water, difficult to feed.

Long-arm Shrimp

Hardy and large.

Can potentially grow very big, highly territorial, predatory.

Pond Snails

Inexpensive, easy to look after.

Can damage aquarium plants, high reproductive rate.


Harmless to most plants, consume algae, don’t breed in aquariums

Some require brackish water, can be difficult to identify.


Fresh Water Invertebrate Health Considerations

Most types of invertebrates are quite low maintenance as far as healthcare goes, so long as the quality and chemistry of your water are kept in optimum condition. With the exception of the pond snail, most types of invertebrates are vulnerable to poor quality water, or water containing high levels of nitrates. While some fresh water invertebrates are able to breathe air, for example apple snails and crabs, most cannot do so, and could quickly succumb in tanks that have poor water conditions.

One of the most important issues to be aware of if you want to keep fresh water invertebrates is that of copper-based medication. These types of medicines should be avoided at all costs, because most types of invertebrates are extremely intolerant of these compounds. Most aquarium medications use copper, and so you will need to check carefully before you go treating your tank.

Another important consideration is that many fresh water invertebrates like to molt. Molting is a complex process, and depends on the animals receiving the right kind of diet and living in the right conditions. Under the wrong conditions, many invertebrates will not be able to molt, and will therefore die.

Dietary Needs

Fresh water invertebrates have special dietary needs that need to be considered. Often overlooked, many aquarium kept creatures eventually starve to death. What you need to remember is that most fresh water invertebrates are essentially scavengers, while others may be filter feeders.

Filter feeders are especially difficult, as they need the appropriate amount of particulate matter to be provided for them on a regular basis. Ideally, you should add a small amount of specialized food for them each day. Algae-eaters meanwhile, will need to be provided with an alternate source of food, because any algae you have in your tank is never enough to sustain them long term.

Regarding snails and many types of crayfish fresh water invertebrates, these creatures need to eat certain kinds of aquarium plants, which will have to be provided for them. Note that many snails will also happily eat your fish eggs, and so they are a definite no-go for any breeding tank.

You also need to beware of certain types of invertebrates that can eat your tropical fish, such as many crabs, long-arm shrimp and crayfish, which are able to catch and eat surprisingly large fish.


To cap it all, fresh water invertebrates can make excellent additions to your aquarium, but don’t go kidding yourself that they are easy creatures to keep. Virtually all types of invertebrates require a level of specialist care, and so you will need to research carefully any kind of creature you are considering keeping, to see if it really is a viable option for you.

Some of the easier fresh water invertebrates to keep are red cherry shrimp!