Amano shrimp

Build grazing space before buying the grazers

Caridina multidentata, formerly sold as Caridina japonica, reaches about 5 cm in the Fishkeeper species account. Plants, wood and other established surfaces give it places to forage; sheltered gaps also let a shrimp withdraw after moulting. A freshly cycled but bare aquarium can process some waste without offering much natural grazing. Do not stock it as though clear water proves the food supply is ready.

Our starting example is a small group of five or six in 40 litres or more. These are editorial planning choices, not experimental minimums: Fishkeeper recommends group keeping but does not specify a number or tank volume. Use a planted base with several accessible feeding and hiding areas rather than relying on height alone. More shrimp require more usable surfaces and food, not simply another few litres on a calculator. A fish community adds its own space and filtration requirements.

Fishkeeper publishes broad ranges of 15-28 C, pH 6.0-8.0 and hardness 6-18 degrees. They describe adaptable aquarium conditions, not a reason to move between the endpoints. Ask which water the shrimp are being held in and plan a careful transition. Keep an established filter running, measure ammonia and nitrite, and match treated replacement water appropriately. Do not preserve deteriorating water merely to avoid change; adjust maintenance to test results and accumulated waste.

Algae grazing is not a complete feeding plan

Visible algae can decrease while the shrimp still need food. Fishkeeper recommends small pellets and algae wafers alongside grazing, and describes shrimp taking a piece away to eat under cover. Supply an appropriate prepared shrimp food rather than assuming fish leftovers will reach them. Follow its feeding guidance, observe intake and remove uneaten portions.

Several small feeding spots are more useful than one large piece monopolised by the first shrimp to find it. Check both directions of competition: fish may intercept food before it reaches the bottom, while an Amano may carry a portion away from a smaller grazer. Food disappearing is not proof that every animal has eaten. Do not respond by leaving a permanent pile of food under the plants.

Keep predatory or aggressive fish out of the plan. Even a fish described as peaceful may investigate a shrimp, especially when it is exposed after moulting. Size and overlapping temperature ranges alone do not establish compatibility. Provide retreats inaccessible to the proposed fish, observe interactions and keep a suitable separate setup available; persistent picking or injuries mean the combination needs changing. An invertebrate-focused aquarium is the simpler option when protecting the shrimp is the priority.

Eggs in freshwater do not mean a freshwater colony

Females can carry eggs and release larvae while living in freshwater. The important distinction is what happens next: the larvae are not miniature benthic shrimp ready to grow alongside the adults. A 2021 study of three amphidromous Caridina species documents the saline larval-development phase of C. multidentata. This is why adult freshwater keeping does not normally produce a self-sustaining colony.

Keep the adult display freshwater. A female carrying eggs is not a reason to salt the community aquarium. Raising larvae is a separate specialist project involving suitable saline water and larval food; adult water ranges in the parameter panel are not larval culture instructions. If your goal is simply to maintain a small group, plan to care for those animals rather than expecting every brood to replace losses.