Crystal red shrimp

Quick facts

Adult size

3 cm

Lifespan

can live up to 2 years

Tank zone

all

Temperament

peaceful

Difficulty

advanced

Schooling

recommended 10+ (critical minimum 5, thrives at 20+)

Water parameters

Temperature

20–24°C

pH

5.5 to 6.8

Hardness

0 to 6 dGH

Tank requirements

Minimum volume

38 L

Minimum length

45 cm

Flow

low

Lighting

dim preferred

Substrate

any

Driftwood

preferred

Hiding spots

needed

Feeding

Diet: omnivore, feeds primarily at the all.

Biofilm, algae, decomposing plant matter, and specialized shrimp food. In an established tank with live plants and a mature biofilm layer, supplemental feeding is minimal. Dedicated shrimp foods (Bacter AE, Shrimp King, SL-Aqua, Glasgarten) are formulated to promote biofilm growth and provide balanced nutrition. Blanched vegetables (spinach, nettle leaves, mulberry leaves) are accepted. Snowflake food (soy hulls) provides a slow-release grazing surface. Protein-heavy foods (frozen bloodworm, fish food) should be offered sparingly; too much protein causes molting problems. Feed every other day in small amounts; less is more with Caridina shrimp. Overfeeding is the fastest way to crash a shrimp tank because uneaten food degrades water quality.

Vegetable matter required (algae wafers, blanched zucchini, spinach).

Compatibility

• Species-only tank is the standard recommendation. Crystal red shrimp (CRS) are Caridina cantonensis, a different genus from the hardier Neocaridina (cherry shrimp). They're more sensitive to water parameters and less tolerant of suboptimal conditions.
• If kept with fish, only the smallest and most peaceful species: otocinclus, pygmy corys, and small, calm nano fish. Even then, shrimplet survival drops because most fish will eat Caridina babies, which are smaller than Neocaridina babies.
• Cannot be mixed with bee shrimp of different color patterns (black crystal, shadow, golden bee) if you want to maintain the CRS coloring. They interbreed freely and the offspring revert to wild-type coloring within a few generations.
• Grades range from C (faint coloring, translucent) through SSS+ (solid opaque white and red with specific pattern distributions). Higher grades are more expensive and generally more fragile because they've been inbred more aggressively to fix the color pattern.

Habitat

Crystal red shrimp are a selectively bred color morph of Caridina cantonensis, originally from streams in southern China and Hong Kong. The wild form is a dull brown-striped bee shrimp found in cool, soft-water mountain streams. The red-and-white mutation appeared spontaneously in a Japanese breeder's colony in 1996 (Hisayasu Suzuki is credited with isolating and stabilizing the first crystal red line). From that initial mutation, decades of selective breeding have produced the grading system used today: C, B, A, S, SS, SSS grades based on the opacity, distribution, and pattern of the red and white coloring. The genetics are complex and not fully mapped; breeders work by visual selection over many generations. CRS require soft, acidic water (pH 5.5-6.8, GH 4-6, KH 0-2, TDS 100-150) which is achieved using RO water remineralized with a Caridina-specific mineral additive (like SaltyShrimp GH+). Buffering substrates (ADA Amazonia, Brightwell, Landen) maintain the low pH by absorbing carbonate hardness. Tank-bred by hobbyist breeders worldwide; the species is rarely found in chain pet stores but is readily available through online shrimp sellers and aquarium club auctions.

Breeding

Breeds in aquariums when water parameters are stable. Females carry 20-30 eggs for 28-30 days before releasing miniature shrimp. No larval stage. Fry are self-sufficient and graze on biofilm immediately. Colony growth is slower than Neocaridina because Caridina are more sensitive to parameter instability, clutch sizes are smaller, and shrimplet mortality is higher. Selective breeding for pattern requires culling lower-grade offspring from each generation. Higher-grade CRS (SS, SSS) are more fragile and breed less prolifically than lower-grade stock, which is why the price scales exponentially with grade. A starter colony of S-grade CRS in a well-maintained tank will produce mixed-grade offspring; expect a bell curve of quality with most offspring at or near the parent grade. Crossing CRS with other Caridina (Taiwan bee, shadow bee, golden bee) is how breeders produce new color patterns, but the genetics become unpredictable and offspring quality is inconsistent for several generations.

Common problems

Molting deaths from incorrect mineral content are the primary killer. GH must be maintained between 4-6 dGH for healthy molting. Too low and the new shell can't harden; too high and the shrimp can't release the old shell. Use a TDS meter and consistent remineralization with each water change. Buffering substrate exhaustion is a slow-creeping problem: the substrate stops buffering pH over 12-18 months, and the pH gradually rises, which stresses Caridina. Monitor pH regularly and replace the substrate when buffering fails. Planaria and hydra prey on shrimplets and establish in shrimp tanks via hitchhiking on plants. Fenbendazole treats planaria; manual removal or traps handle hydra (chemical treatments for hydra risk shrimp health). Bacterial infections ("white ring of death" at the molt line, "rust disease" showing as brown patches on the shell) indicate either parameter instability or opportunistic bacteria from poor water quality. No reliable chemical treatment; prevention through stable parameters is the only approach.

Bioload

Bioload coefficient: 0.1 (negligible like all dwarf shrimp).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• Water chemistry for fishkeepers: pH, GH, KH, and what they mean