Caridina Japonica - The algae eater

Family Atyids

Genus Caridina

Origin: Japan, Taiwan

Commercial Name: algae eater shrimp, Amano shrimp

Size: up to 5 cm for females, what become larger than males

Adequate Environment: slightly salty water

Temperature: 23 to 28C

Feeding algivorous

Utility: its favorite food is often a major concern for aquaria hobbyists.

Particularity:  almost transparent.  Lives in swarms representing hundreds of individuals.  In aquarium it will eat up Riccia fluitans if no other food source is available.


Superb female with her eggs.

After an algar meal, a little snail sweet :-)) Interspecific compatibility.  Regular size snails are not disturbed.
As observeable, this shrimp has eaten everything but algae.  It can survive thanks to this diet adaptation but moults occur less frequently and the general condition is not excellent.

The breeding mode I observed is very peculiar.  Males group around the female(s) and mass fertilization takes place.  A bunch of caridinas that scatters at the slightest sign o danger.

These shrimps live in sweet water but the larvae that are released after incubation are far from looking like the adults.  They are authentic swimmers and quite incapable of grasping a surface.  In nature, the larvae are driven by the water current towards brackish waters.  For this reason, any breeding attempt in freshwater is bound to fail, the larvae die within 6 days.

The breeding principle is quite simple, as long as some rules are respected:

The adults do not survive in brackish or sea waters, it is therefore necessary to foresee a second aquarium for the transfer of the larvae.  As soon as the latter are released from the female abdomen, one must capture them - what can be achived by providing a small light spot, attracting them so as to syphon them out.

The these tiny beings are transferred to the growth aquarium, what has been previously filled with water from the main tank so as to avoid any shock due to parameter changes.  This water salinity must then be gradually raised, until it reaches the about 17 grammes per liter - anticipating your question: YES, kitchen salt will do fine.

The transition towards this salinity level must be carried out in about 5 days, so as to simulate the passage of the larvae through the several water salt levels in nature - As a reminder, the larvae viability in freshwater represents 6 small days.

These larvae will be fed preferably with plancton (algae / infusoria), nevertheless, the procedure applied in the killie breeding hobby to feed artemia salina is also viable (Yeast that is used to feed the infusoria which in turn feed the Caridina larvae); when their size reaches about 3 to 4 mm the procedure is inverted as at this stage their morphology resembles the adults.  The transition is operated the same way, i.e. a lowering of the salt level in about 5 days through water changes. Nevertheless, the most precise system consists in having a different aquarium for each phase of the salt level lowering; the  juveniles are transferred from aquarium to the other until they reside in the last one, with a salt level of about 5 grammes / liter.

Finally the juvenile shrimps are transferred back in the first tank, that is, the tank containing the breeding adults - no canibalism phenomenon will occur. It will however be necessary to feed them with food appropriate to their size.  Personnally I only use plancton, algae, vegetables and powdered food initially dedicated to juvenile fish.