Darwin Algae Shrimp (Caridina Ntnilotica)



Caridina Ntnilotica is also known as “Darwin Algae Shrimp” or “Darwin Algae Eater Shrimp” is a freshwater shrimp species belonging to the Atyidae family. It was named after P. Roux’s researches in 1833. Its natural habitat extends through Africa in spacious geography between the Nile River in Egypt to Lake Sibaya in South Africa. It is the only shrimp species found in Lake Victoria, the source of the Nile River. On the other hand, according to some sources, the homeland of this shrimp is the northern part of Australia. The fact that, a significant portion of the resources on this shrimp species belong to Australia also strengthens this claim.

Although they are confused with the Caridina Longistiris, they differ from each other. Darwin Algae Shrimp has light green, red and orange coloration depending on its emotional state, what they eat, or the environment accordingly. One of its distinctive features is that it has a white stripe extending from its head to its tail.

Male shrimps are smaller and less colorful, while female shrimps are larger and more colorful. These small shrimps can reach 4-5 cm in length.

Water Parameters

Temperature: 22-27 °C
pH: 6,5 – 8,0
Hardness: 2 – 12 dGH

The care conditions for this shrimp are similar to snails. They prefer to live in aquariums that have high-quality clear water with a biofilm formation. However, unlike snails, they cannot tolerate water pH too much. Soft and medium water hardness are the environments that they can live best. On the other hand, sudden water temperature changes can also harm these shrimps. For this reason, it is ideal to use a heater and a thermostat to stabilize the water temperature.

Due to their size, they can also be kept in tanks with small sizes. It is a peaceful shrimp but may not be able to live in harmony with fish that show territorial protection or in large sizes. It has been observed from time to time that these shrimps are eaten due to their small size. Therefore, it gets along better with tank mates that are close to its size with peaceful behavior. Aggressive and large fish can always pose a threat to it.

It is a shrimp that usually have active behavior. Caridina sp. Ntnilotica is a brave shrimp that can compete with smaller fish over food. They are also hardy in case the necessary aquarium conditions are set properly. If there is a momentary slowdown in its movements, this is due to its cautious attitude towards its tankmates. If this slowness lasts longer, it may be a sign of various diseases. For more information on freshwater shrimp diseases, see our health and diseases section here!

Since Darwin Algae Shrimp do not harm the aquatic plants, they can live in harmony with them and mostly preferred to keep in the planted aquariums.


As it is named after, this shrimp species is a good algae eater. The natural feeding areas in the wildlife are the rocky areas densely covered with moss and algae populations. For this reason, it is substantial to provide the algae source or ensure algae growth to keep them healthy in the aquarium. In a separate tank, exposing rocks or other decorations to high light to grow algae and then placing them in the shrimp tank to provide algae is a useful method that can be helpful. When there are no algae or when it is insufficient, they can be fed with dry food. Apart from these, it can survive by feeding on microorganisms in the water if they exist in proper amounts. But their first choice will always be algae.


There is very little information about the reproduction of this shrimp species. There are some observations in Australia for the mating time of these shrimps. For instance, before mating female molts and is surrounded by males and mating occurs during this molting periods. After mating, the female carries gray eggs and incubate them until they hatch. Cultivation of these eggs in freshwater has been tried but unfortunately failed. As a result of the experiments, when half-strength saltwater conditions were provided, it was observed that the survival rate increased significantly. When new-borns grow up and begin to resemble their parents, they move into freshwater environments in their natural habitat. But in captive breeding, the juvenile shrimp must be manually removed to the freshwater environment. It is also significant to provide the proper amount and correct type of plankton source to raise the shrimp fry.

As a result, like Nerite snails, or the Amano Shrimps, a saltwater environment requirement for breeding has made it difficult to breed this species. Also, they cannot tolerate parameters such as water temperature and pH level well. There is always a risk of being prey to some fish due to their small size. For this reason, this shrimp is often recommended for experienced aquarists.

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