Family: Atyidae
Blue Tiger Shrimp — the orange-eyed blue morph of Caridina mariae from Guangdong and Hong Kong hill streams. Reaches 2.5-3 cm, needs clean soft water at 20-26 °C (pH 6.0-7.2), a little easier than crystal shrimp; breeds in freshwater.
Blue Tiger Shrimp is the blue morph of Caridina mariae, a hill-stream atyid from Guangdong, Hong Kong and northern Vietnam whose wild form is banded in black and cream. Taiwan breeders selected the blue-orange-eyed strain in the 2000s, and the best specimens are now a vivid sky-to-royal blue with the species' signature glowing orange eyes — the combination that made 'Orange-Eye Blue Tiger' one of the most sought-after caridinas of the last two decades. It grows slightly larger than bee shrimp at 2.5-3 cm and is a little more forgiving than the cantonensis line: 20-26 °C, mildly acidic to neutral soft water around pH 6.0-7.2 and 4-8 dGH, clean and stable but not as knife-edge as crystal shrimp. In the aquarium it is active, hardy and a constant algae grazer over wood and stone. Breeding happens in freshwater, though clutches are modest and the fry develop slowly. A group of blue tigers over dark stone with moss is one of the classic displays of the Asian shrimp hobby.
Difficulty: moderate. Very peaceful. Groups of 5 or more.
Aim for 20–26 °C. Stable 20–26 °C; cooler than Sulawesi species; 20–26 °C stable range.
Full size is 3–4 cm. Minimum tank: 30 L, with open swimming space along its bottom — grazing hardscape and leaves habits.
Algae and aufwuchs grazer; quality shrimp foods. It forages naturally over active soil or dark fine gravel, so let some food reach the bottom.
Very peaceful; groups of 5 or more. Good company: Other Caridina mariae morphs — Same species line; keep colors separate, Soft-water Caridina morphs — Overlapping chemistry works, Otocinclus catfish — Gentle, compatible. Keep away from Neocaridina color shrimp — Different chemistry preferences, Copper-based medications — Lethal to all invertebrates, Large predatory fish — Shrimp are prey.
Native to Southeast Asia — hill streams, where it lives in cool, clean hill streams over rock and leaf litter. Gentle to moderate current; Moderate to high oxygen.
In the aquarium: breeds in freshwater. The female carries 15-25 eggs for about four weeks; fry are small and slow but survive on biofilm and fine powder in a mature tank.. Females are larger, deeper and more intensely blue; males slimmer, smaller and paler..