Freshwater aquarium invertebrates provide you, the aquarist, with a great automatic clean up crew for the home aquarium. Learn how freshwater invertebrates can save you time with aquarium maintenance!
When you first start out in the freshwater aquarium hobby, you may not realize that your selection of tank inhabitants can include freshwater aquarium invertebrates and don't need to only be limited to fish. A variety of freshwater invertebrates are also available and these creatures can perform several helpful functions in your tank. Invertebrates like snails, shrimp, crayfish and crabs are scavengers that can help rid your tank of built-up fish food and other waste products, thus making your tank a healthier environment for your fish. If are looking for a simple way to keep your tank clean, consider adding a freshwater invertebrate to your tank.
Benefits and Drawbacks of Keeping Invertebrates
The main benefit of keeping invertebrates in your tank is that they will help to control the build-up of detritus in your aquarium. Detritus is a term that refers to organic waste and uneaten fish food that builds up in your aquarium substrate, affecting the water quality in your tank. Invertebrates are often referred by aquarium hobbyists as a sort of “cleanup crew” because they naturally feed on these materials, thus safely removing them from your tank. Another benefit of freshwater invertebrates is that many of them are quite colorful and can add to the overall appearance of your tank. Some lobsters, for example, come in bright blue colors and some aquarium snails have shells that form in unique shapes.
One of the drawbacks to freshwater invertebrates is that some of them can be difficult to keep. Many invertebrates are sensitive to water quality and may not be able to tolerate medications like malachite green if you add them to your aquarium. In some cases, invertebrates are also likely to become aggressive. This is especially likely in dirty tanks and in tanks where the invertebrates do not have access to an adequate supply of food. Additionally, certain species of ornamental aquarium snails may damage live plants so they should be used with caution in planted tanks.
Types of Freshwater Aquarium Invertebrates
Snails – Freshwater aquarium snails come in a variety of shapes, sizes and colors. Some of the more popular species of freshwater snail include the Nerita Snail, Gold Rabbit Snail, Japanese Trapdoor Snail and the Assassin Snail. These invertebrates are ideal for controlling algae in the home aquarium and they will also scavenge for detritus and leftover fish food. In order to ensure that your snails have plenty to eat, supplement their diets with flake or pellet foods. Freshwater aquarium snails typically do not grow larger than 3 inches and most species are unlikely to overpopulate. In the event that you do have an overly abundant snail population, however, the Assassin Snail can be a useful invertebrate because it feeds on other snails. I use Nerite Snails in my aquariums. In my opinion, these are the best snails for freshwater aquariums. They're very efficient cleaners and will not re-produce in freshwater so there's never a problem with overpopulation. You can find a very good selection of Nerite Snails here at a very reasonable price. I usually put in 1 Nerite snail for every 1 - 2 gallons.
Lobsters – Also called crayfish, freshwater aquarium lobsters come in a variety of colors ranging from dull brown to striking blue. Lobsters are peaceful creatures and do not typically bother fish, but they can become very territorial and aggressive if kept with others of their own species. For this reason it is recommended that lobsters be kept singly in tanks no smaller than twenty gallons. Lobsters prefer a tank environment with plenty of rocks and plants to use as cover. These invertebrates are scavengers, likely to eat any food that sinks to the bottom of the tank. In order to maintain their health, however, their diet should be supplemented with an appropriate crayfish food such as sinking pellets and dried algae. Crayfish can climb out of the aquarium so be sure to install a tight fitting fish tank hood!
Shrimp – In the freshwater aquarium, shrimp will feed on algae, organic waste and leftover fish food. If you plan to keep multiple shrimp, or if you have a particularly small tank, it may be wise to supplement the diet of these invertebrates with quality flake or pellet foods. Freshwater aquarium shrimp come in a variety of colors ranging from transparent, or no color, to bright red or blue - some shrimp are even able to change color. These invertebrates should be kept in tanks with peaceful fish where they have plenty of places to hide. Different species of shrimp grow to different sizes at maturity but, for the most part, these invertebrates remain small – generally less than 2 inches long. Here's a good source for freshwater aquarium shrimp.
Crabs – The most popular type of crab for freshwater aquariums is the mini crab, also known as the fiddler crab. These creatures are very hardy creatures which makes them relatively easy to care for. Mini crabs require some salt in their water in order to thrive because they originate from the brackish waters of lagoons and swamps. In the home aquarium, crabs will scavenge for detritus and uneaten fish food, though it is wise to supplement their diets with fresh or freeze-dried foods like bloodworms and brine shrimp. The ideal tank for a crab will have plenty of rocks and driftwood to offer hiding places as well as things for the crabs to climb. One of the most important things to realize about these invertebrates is that they are semi-terrestrial – they need to be able to access dry land.
Clams – Freshwater clams, an often overlooked freshwater invertebrate for the home aquarium, help to keep aquarium water clean by filtering out detritus and uneaten fish food from the water column. These invertebrates may also help to lower nitrate levels. Clams typically like to bury themselves in substrate, but if you watch closely you may be able to see their siphon protruding from the substrate. While these invertebrates garner most of their required nutrients from the water itself, you can supplement their diets with quality invertebrate food. When housing clams in your aquarium, avoid using any copper-based medications because clams are unable to tolerate them and could die if exposed.
Additional Tips for Freshwater Aquarium Invertebrates
When selecting an invertebrate for your aquarium, take the size of your aquarium and the adult size of the invertebrates you are considering into account. You should also keep in mind that some freshwater invertebrates, like lobsters, are territorial and should be kept singly or in large aquariums. Before you bring an invertebrate home, research not only the type of invertebrate, but the particular species, so you will be aware of any precautions you need to take to protect your aquarium fish and to ensure that you are able to properly care for the creature.
While invertebrates may feed largely on the detritus in your aquarium this does not mean that you will not need to supplement their diets. In small tanks, and tanks with multiple invertebrates, the food supply in the tank may be fairly limited. In order to keep your invertebrates healthy you will need to care for them just as you care for your fish – by providing them with a diet that fulfills all their nutritional needs. Most invertebrates are omnivorous and should be offered fresh vegetables and sinking pellets or wafers to supplement their diets. Some freshwater invertebrates, like lobsters, may also feed on the live and frozen foods you offer the fish in your tank.