Amano Shrimp (Caridina multidentata) Care Guide
Caridina multidentata is a large translucent freshwater shrimp from Japan and Taiwan, valued as a strong algae eater; larvae require brackish water to develop.
Compiled by Aquairi from published sources · Published · Updated
Overview
Caridina multidentata is a translucent freshwater shrimp in the family Atyidae, native to southwestern Japan, Taiwan and Korea. It was introduced to the planted-aquarium hobby by Takashi Amano in the 1980s, after whom it is commonly named. Adults reach 4-5 cm, making it noticeably larger than Neocaridina davidi.
Taxonomy
- Family: Atyidae
- Genus: Caridina
- Scientific name: Caridina multidentata
- Former name: Caridina japonica (renamed 2006)
- Common names: Amano Shrimp, Yamato Shrimp, Japanese Marsh Shrimp
Habitat
The species is amphidromous: adults live in freshwater streams in southern Japan, Taiwan and Korea, females release eggs that hatch into larvae which drift downstream to brackish estuaries, develop there, then return to freshwater as juveniles. Bodies show a translucent base colour with broken reddish-brown lines along each side.
Tank requirements
- Minimum tank volume: 40 L (10 gal)
- Temperature: 18-28 C (64-82 F)
- pH: 6.5-7.8
- GH: 6-14 dGH
- KH: 2-10 dKH
- TDS: 150-400 µS/cm
- Lifespan: 2-3 years
- Water type: neutral medium-hard freshwater (adults)
Diet
Omnivore. Excellent grazer of soft green and brown algae, hair algae and biofilm. In a stable aquarium algae alone may be insufficient — supplement with sinking shrimp pellets, blanched zucchini or spinach. Like all atyid shrimp, the species is highly sensitive to copper.
Compatibility
Peaceful and reef-unrelated. Safe with tetras, rasboras, Otocinclus and Corydoras. Avoid Cichlids, Goldfish and Crayfish. Does not interbreed with Neocaridina.
Breeding
Practically impossible in standard freshwater aquaria. Females carry several hundred small green eggs for ~5 weeks, but hatched larvae require brackish water (approx. 1.018-1.024 SG) to complete metamorphosis before returning to freshwater. Almost all shrimp sold in the hobby are wild-caught or farmed under brackish facilities.
Amano Shrimp Breeding Guide
Overview
The Amano shrimp, Caridina multidentata, is a larger algae-eating shrimp native to Japan, Taiwan and Korea. Unlike the cantonensis morphs, it is amphidromous: Wikipedia states that oviposition and hatching occur in freshwater, the newly hatched larvae drift to saltwater to develop as juveniles, then return to freshwater as adults. This life cycle makes it very difficult to breed in a standard home aquarium.
Reaching adult size, it typically grows to 25-35 mm and feeds primarily on algae. Wikipedia gives a temperature range of 18-28 °C and pH of 6.5-7.5 for the species.
Sexing
Females are larger than males. Wikipedia notes that females can be distinguished by a more elongated lower row of dots along the body, while males show a row of evenly spaced dots.
Conditioning
Adults condition easily in a planted freshwater tank with stable parameters and abundant algae and biofilm. Well-fed females will develop eggs readily; the difficulty lies entirely in rearing the resulting larvae, not in spawning.
- Stable freshwater tank, 18-28 °C, pH 6.5-7.5 (Wikipedia)
- Plenty of algae and biofilm plus supplemental feeding
- A separate brackish rearing tank prepared in advance
Breeding Setup
Successful breeding needs two tanks: a freshwater tank where the female carries and hatches eggs, and a dedicated brackish rearing tank for the larvae. The Shrimp Farm notes larvae tolerate a wide salinity, with one study citing 17-34 ppt (about 1.0128-1.0256 specific gravity); marine salt, not aquarium tonic salt, is used to mix it.
Spawning & Berried Females
Wikipedia describes the eggs as oval and rich in yolk. The Shrimp Farm states females typically carry the eggs for about 4-5 weeks. As the eggs near hatching, the larvae must reach brackish water promptly, because they survive only a short time in pure freshwater.
Shrimplet/Larval Care
The hatchlings are planktonic zoea, not miniature adults. They must be moved to the brackish tank and fed microscopic food such as cultured phytoplankton and the algae growing on the tank walls. The Shrimp Farm indicates the larvae develop in brackish water for roughly 30-60 days; once they metamorphose into post-larvae they are gradually returned to freshwater.
Common Challenges
The Amano is an expert-only breeding project. Larvae die quickly if they do not reach brackish water in time, the weeks-long larval feeding is demanding, and the salinity must be reduced gradually as juveniles metamorphose, per The Shrimp Farm. For most keepers Amano shrimp effectively do not reproduce in freshwater home tanks.