English name: Dark Green Shrimp
Scientific name: Caridina sp."Dark Green"
Origin: India
Size: 1.2 in / 1.4 in (male/female) 3 cm / 3.5 cm
Water temperature: 68 - 82 °F / 20-28 °C
Recommended pH range: 6.8 - 7.5 (preferably 6.8-6.9)
Behaviour: non-aggressive
Difficulty: easy
Breeding rate: medium

Introduction to Dark Green Shrimp

The Dark Green shrimp is a member of the genus Caridina, but exactly which species remains unknown. A lot of different guesses are currently circulating within the hobby and the shrimp has been attributed with several different scientific names. Some breeders suspect that it is actually not a variant of a known species but a new species that has not been scientifically described yet.

The Dark Green shrimp is sometimes confused with the Caridina babaulti sp. "Green", but the latter one is not as dark green as the Dark Green shrimp. The Dark Green shrimp retains its intense dark green colour throughout its entire life, while Caridina babaulti sp. "Green" is known to change colour.

Another way of distinguish them from each other is to wait for them to breed; the offspring of the Dark Green shrimp are red when they hatch grows much faster than that of Caridina babaulti sp. "Green". Dark Green shrimp offspring are extremely small when they emerge from the egg but will normally double in size within the first 10 days.

Unfortunately, quite a few sellers still confuse these two shrimps with each other and sell Caridina babaulti sp. "Green" as Dark Green shrimp. Make sure you buy from a breeder that knows how to distinguish the two.

Geographical origin and habitat

The Dark Green Shrimp hails from Asia, but its exact origin is unknown. It seems to have made its entrance to the hobby in 2007. 

Physical appearance

The Dark Green shrimp sports an intense dark green colour. Females are even darker than the males. Unlike several other shrimps the Dark Green shrimps never change colour; they keep the dark green colouration throughout their entire lives. 

The eggs are of a bright lime green shade which contrasts nicely against the dark green colour of the mother. Newly hatched offspring are dark red. 

Keeping Dark Green Shrimp

The Dark Green shrimp will do best in slightly acidic conditions, ideally 6.8-6.9. It will however tolerate a pH-value up to 7.5. The temperature should be kept in the 68 - 82 °F / 20-28 °Crange.
Keep the level of soluble waste low. If you encounter problems, it is okay to refrain from feeding for a few days until you have rectified the problem. 
Avoid rapid changes in water chemistry and temperature; all changes should be slow and gradual to give the Dark Green shrimp a change to adapt.  

Feeding Dark Green Shrimp

Do not feed your Dark Green shrimp more food that it can eat in 2-3 hours. If your shrimps are reluctant to come out and look for food, feed them when the aquarium is dark. If this is not enough, you may have to provide them with more hiding spots in the tank. It can also be a good idea to check if they are being bullied by other tank mates.

Sexing and breeding Dark Green Shrimp

The male Dark Green shrimp is smaller than his female counterpart and the female normally looks bulkier. In addition to this, the female shows a much darker shade of green than the male. Sexing this species is therefore very easy.   

The eggs are bright lime green which contrasts beautifully against the dark green body colour of the female shrimp. This contrast also makes it easy to spot when a female is with eggs.   

The offspring is very small when they hatch and displays a dark red coloration. They grow very fast and will soon mature into adults. You can expect them to double in size within the first 10 days.