Amano Shrimp

The Amano Shrimp, also known as the Algae Eating Shrimp or Caridina japonica, is widely considered the best algae-eating shrimp in the aquarium hobby. Named after the famous aquascaper Takashi Amano who popularized them, these translucent shrimp are workhorses that tirelessly clean algae from aquarium glass, plants, and decorations. They are larger than Cherry Shrimp (up to 2 inches), more hardy, and better at eating various types of algae including hair algae and black beard algae that other algae eaters avoid. Amano Shrimp are peaceful, active, and excellent additions to planted community tanks. They cannot successfully breed in freshwater (require brackish conditions for larvae), so all specimens are wild-caught or farm-raised.

Care Requirements

Tank Setup

Amano Shrimp are undemanding:

• Minimum 10 gallons (20+ recommended)
• Heavily planted - provides biofilm and security
• Sponge filter or gentle hang-on-back (avoid strong currents)
• Heater to maintain 70-78°F
• Dark substrate to make them visible
• Driftwood and rocks for grazing
• Hiding spots essential (especially when molting)
• No copper medications - deadly to all shrimp

Important: They need places to hide when molting (shedding their exoskeleton). They are vulnerable during this time.

Water Quality

• Temperature: 70-78°F (21-26°C)
• pH: 6.5-7.5
• Water Hardness: Moderate (6-15 dGH)
• Ammonia/Nitrite: 0 ppm (extremely sensitive)
• Nitrate: <20 ppm
• Copper: ZERO tolerance

Maintenance:

• Weekly 20-30% water changes
• Very sensitive to ammonia and nitrite
• Stable parameters more important than exact numbers
• Never use copper-based medications

Feeding

Amano Shrimp are algae-eating specialists:

• Algae: Their primary food source
• Algae wafers: Supplemental feeding
• Blanched vegetables: zucchini, cucumber, spinach
• Biofilm: Naturally occurring on surfaces
• Detritus: Clean up leftover food and waste

Feeding Schedule: Minimal supplemental feeding needed in established tanks with algae.

Note: If algae is scarce, feed algae wafers or blanched vegetables 2-3 times per week.

Behavior & Compatibility

Peaceful scavengers:

• Good Tank Mates:

  • Small tetras
  • Rasboras
  • Corydoras
  • Small gouramis
  • Otocinclus
  • Other peaceful community fish
  • Other shrimp species

• Avoid With:

  • Large predatory fish (angelfish, cichlids)
  • Goldfish (will eat them)
  • Bettas (may kill them)
  • Loaches (most loaches eat shrimp)
  • Any fish large enough to fit them in mouth

Behavior: Constant grazing on algae and biofilm, active throughout the tank, climb on plants and decorations.

Algae Control

Best algae eaters in the hobby:

• Hair algae: Excellent at eating
• Black beard algae: Will eat when hungry
• Green spot algae: Constantly grazing
• Brown algae: Readily consume
• Green algae: Primary food source

Note: They won’t eat all algae types, but they’re the most effective freshwater algae eaters.

Breeding

Cannot breed in freshwater:

• Eggs: Female carries eggs under tail
• Larvae: Released as planktonic larvae
• Brackish requirement: Larvae need brackish water to develop
• All specimens: Wild-caught or farm-raised
• Difficulty: Impossible in home aquariums

Note: Females will still carry eggs in freshwater, but larvae die without brackish conditions.

Health Considerations

Generally hardy but sensitive:

• Copper sensitivity: Fatal exposure
• Calcium needs: For shell development (moderate hardness)
• Molting issues: Can get stuck in old shell
• Acclimation: Drip acclimate slowly when adding to tank

Prevention:

• Never use copper medications
• Maintain appropriate water hardness
• Provide hiding spots for molting
• Drip acclimate new shrimp (1-2 hours)

Size Considerations

Larger than most dwarf shrimp:

• Adult size: 1.5-2 inches (females larger)
• Sexual dimorphism: Females larger, often with saddled eggs
• Lifespan: 2-3 years

Appearance

Translucent with subtle markings:

• Body: Clear to light gray, sometimes greenish
• Markings: Faint dotted lines along body
• Size: Robust, larger than Cherry Shrimp
• Sexing: Females larger with rounded underbelly, males slimmer

Molting

Critical process for growth:

• Frequency: Every few weeks when young, less often as adults
• Behavior: Hide when molting, very vulnerable
• Old shell: Leave in tank - they eat it for calcium
• Failed molts: Can be fatal, ensure proper water hardness

Tank Maintenance

• Weekly 20-30% water changes
• Let algae grow on some surfaces (their food)
• Remove uneaten supplemental food
• Test for copper before adding any medications
• Monitor other tank inhabitants for aggression

Tips for Success

• Drip acclimate slowly when introducing to tank
• Keep in groups of 3+ (they are social)
• Provide plenty of algae or supplemental feeding
• Never use copper medications
• Ensure moderate water hardness for shell health
• Keep with peaceful, small fish only
• Heavily plant the tank for security
• Leave old shells in tank for calcium
• Supplement feed if algae is insufficient
• Secure lid - they can climb out

Comparison to Cherry Shrimp

• Amano: Larger (2”), better algae eaters, don’t breed in freshwater, more active
• Cherry: Smaller (1”), breed easily, breed in freshwater, colorful
• Both: Peaceful, need similar care, good for planted tanks

Why Best Algae Eater

• Hardiness: More tolerant than other shrimp
• Size: Large enough to avoid many predators
• Efficiency: Constant grazers, work non-stop
• Variety: Eat more algae types than other shrimp
• Activity: Visible and active during day