The accompanying fauna in the aquarium is made up of beneficial insects and pests. It is not easy for the layperson to distinguish these organisms from each other. Harmful aquatic life can be freely moving or sessile. They usually pose a danger to the fauna.
What pests can appear in the aquarium and how do you combat them?
Pests such as planarians, snail leeches, hydra and dragonfly larvae can occur in the aquarium. They pose threats to snails, shrimp eggs, fish fry and shrimps. To combat them, various methods such as special traps, natural predators or manual removal can be used.
Planaria
These flatworms are predatory and are often found in aquariums. They are fast and capture nimble prey such as amphipods or isopods, into which they inject paralyzing substances and digestive juices. Flatworms pose a threat to snails and shrimp eggs.
Most species are brownish to white and can grow up to two centimeters long. The light-sensitive aquatic creatures prefer darker areas. They are easily confused with harmless disc worms, which, unlike planarians, do not have eye spots or throat spots or a branched intestine.
Combat
Special planarian traps (€10.00 on Amazon) are filled with protein-containing food and sunk into the water. After a day, remove the trap and dispose of the pests. The natural predators include tiger loaches, which are also suitable for smaller aquariums, or the predatory red-spotted goby. The four centimeter long organisms are group animals and feel comfortable in swarms of at least five animals. Shrimp are not good roommates because they serve as live food.
Snail Leeches
The teardrop-shaped and up to three centimeters long animals are colored milky white or greenish to brown-red, depending on the species. They have a comparatively hard surface and when threatened, they curl up into a hedgehog shape. Their mode of movement is typical, which is reminiscent of a caterpillar. They suck out snails and feed on worms. Since the aquarium pests occur sporadically, they are easy to collect.
Hydren
These freshwater polyps are significant pests in shrimp farming. They colonize exposed areas such as stones and aquarium decorations in order to grab prey with their tentacles. Expanded hydra populations cause stress for shrimp as they have no place to settle. The creatures can grow up to two centimeters long. Such exceptionally large specimens pose a danger to small fry.
Measures
If you pluck a hydra from the aquarium glass by hand, individual cells can remain behind and grow into a new organism. Instead, scrape off the harmful creatures with a sharp blade cleaner and vacuum them up with a hose.
Dragonfly larvae
Native species are protected and indicate good water quality. In the closed aquarium, 98 percent of all dragonfly species come from Asian regions and are introduced through aquatic plants. Consult an expert to positively identify the species. If they are non-native specimens, they can be caught out of the water with a landing net.
Appearance and lifestyle:
- Mouthparts that are formed into tentacles are typical
- move with three pairs of legs
- feed predatorily on young fish and shrimp
- lead a hidden way of life
