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Aquatic Stocking Density Calculator

Calculate zebrafish stocking density and check compliance against EU/IACUC guidelines for larvae, juvenile, and adult fish. Color-coded status with redistribution recommendations.

ZebrafishStocking DensityIACUCClient-Side
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Load example stocking density data to see the full workflow

Tank Configuration

  • Checking if your tank stocking density meets published consensus or IACUC guidelines
  • Planning fish redistribution after colony expansion or tank consolidation
  • Documenting compliance for IACUC protocol submissions or renewals
  • Calculating maximum tank capacity for different life stages

Don't use for

  • As a substitute for your institutional IACUC-approved protocol — always follow your own SOP
  • For non-zebrafish species — density guidelines differ significantly between species
  • Without considering water quality — density limits assume adequate filtration and water changes

Stocking Density and Zebrafish Biology

Stocking density directly affects zebrafish welfare, growth, reproduction, and experimental outcomes. Overcrowding increases aggression, chronic stress (measured by cortisol), and susceptibility to disease. It also degrades water quality through increased ammonia and nitrite production.

Key biological effects of overcrowding: - Stress: Elevated cortisol levels impair immune function and alter behavior - Growth: Reduced growth rates and body condition in overcrowded tanks - Reproduction: Decreased spawning frequency and fertilization rates - Aggression: Increased fin nipping and territorial behavior - Disease: Higher pathogen transmission rates in dense populations

Conversely, extremely low densities can also be stressful for this shoaling species. A minimum of 5 fish per tank is generally recommended to maintain normal social behavior.

Regulatory Framework for Aquatic Housing

Zebrafish housing density is governed by a combination of international directives, national regulations, and institutional protocols:

  • Aleström et al. (2020) consensus: Recommends 4–10 adult zebrafish per liter for long-term housing
  • EU Directive 2010/63/EU: Requires appropriate housing conditions for research animals but does not specify numeric fish stocking densities
  • US Animal Welfare Act: Does not cover fish, but NIH-funded research follows the Guide for the Care and Use of Laboratory Animals
  • IACUC protocols: Each US institution sets its own density limits through the Institutional Animal Care and Use Committee
  • EU Delegated Directive 2024/1262 (effective Dec 2026): Will specify max 10 adult zebrafish per liter
  • AAALAC accreditation: Facilities seeking AAALAC accreditation must demonstrate compliance with accepted guidelines
  • Zebrafish Book (Westerfield): A widely referenced resource for husbandry best practices

When in doubt, always follow the most conservative guideline applicable to your institution and funding source.

Frequently Asked Questions

Next Steps

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