The invertebrate algae police - shrimp and snails as a cleanup crew

Table of contents

• Dwarf and amano shrimps
• From posthorn to piano snail
• INFOBOX: Prevention is better than cure
• Making algae eatable
  
  

Shrimps and snails are often mentioned as algae eaters, here a yellow form of the back-lined shrimp(Neocaridina davidi) and posthorn snails(Planorbarius corneus).

Unfortunately, not all snails and all shrimps eat all algae, so depending on the problem, disappointment is inevitable. However, what the remnants recyclers can do excellently is algae prevention. Often algae are the result of nutrient peaks in the aquarium, and because shrimps and snails like to take care of food remains, these nutrients are then no longer available to the algae. So the cleaning troop has its sense, even if not all algae are eaten gladly.

Higher algae like these brush algae, which belong to the red algae, cannot be eaten by the small scissors carriers(Neocaridina davidi).

Dwarf and Amano shrimps

As aufwuchsfresser feed dwarf shrimps from the genera Neocaridina, Paracaridina and Caridina basically from everything that forms in the aquarium on surfaces - this includes young algae and thin algae films. Against hard coatings and higher algae such as brush and beard algae, thread, fuzz or fur algae, however, their small claws do nothing. Dwarf shrimp are therefore suitable for algae prevention, but less so for algae control.

However, Amano shrimps are an exception to this rule. They are considered a "wonder weapon" against filamentous algae and nibble at the green strands with great enthusiasm. The younger specimens are particularly effective. Bearded algae and other red algae, on the other hand, are not eagerly eaten; they only crunch away dead specimens.

Dwarf shrimps are growth eaters and therefore also feed on algae, here the bumblebee shrimp(Caridina breviata).

From posthorn snail to piano snail

The smaller aquarium snails, like dwarf shrimp, eat only the finest algae films, not higher or even hard algae. Their feeding marks on the aquarium glass are typical.

Aquarium snails from the mermaid family (racing snails, limpets and staghorn snails) are excellent growth eaters and rasp away thin algae coatings on the aquarium glass and on the decoration very effectively over time. They are often sold as "algae eaters", but they also disdain hard and coarser structured algae. In heavily algalized aquariums racing snails leave the typical feeding marks. However, one should not expect miracles from them either, the panes are not cleaned sparkling clean overnight.

They are also called brush algae snails, but the name is deceptive. Although very young brush algae may be nibbled, older, harder populations are largely safe from the piano snail. Their rasping tongue is not hard enough for them to handle.

Posthorn snails rasp at the algae films as they form on aquarium glass.

Amano shrimp(Caridina multidentata) are considered a magic bullet against filamentous algae.

Although it is also called brush algae snail, this gastropod cannot crack larger populations either. Photo: Alexandra Behrendt

INFO BOX: Prevention is better than cure

If you have algae problems, you should always look for the cause instead of relying on algae eaters. In most cases, an algae infestation is due to an imbalance of fertilization, light and CO2, which weakens the aquarium plants and plays into the algae's hands. However, the algae eaters can support the measures. Caution: most anti-algae agents contain copper and are therefore very toxic to other plants, shrimp and snails.

 
If everything is already so algal, shrimps and snails do not help any more, then the cause must be turned. Photo: Bernd Kaufmann

Make algae eatable

Beard algae, brush algae and other red algae are hard and are eaten only very reluctantly. However, if they are sprayed in the aquarium with a glutaraldehyde-based algaecide or with a higher concentration of hydrogen peroxide, they die and become softer. The invertebrate "algae eaters" then gladly take on these remnants.

Racing snails(Neritina sp.) are excellent auric acid eaters, but they won't be squeaky clean overnight either.

Text: Ulli Bauer, Photos: Oliver Mengedoht