Evaluating and Optimizing Fish Health and Welfare During Experimental Procedures

Area of Science:

• Aquatic animal welfare
• Laboratory animal housing
• Zebrafish husbandry

Background:

• Facilities often house fish in static containers post-procedure for identification.
• Static housing limits access to filtered water and continuous feeding.
• Concerns about fish welfare in static housing prompted the development of improved systems.

Purpose of the Study:

• To compare water quality between static housing and a novel individual housing system (GeneS).
• To assess the impact of housing systems on key water quality parameters for zebrafish.
• To determine the effectiveness of recirculating systems in maintaining optimal aquatic environments.

Main Methods:

• Water quality parameters (ammonia, nitrite) were monitored in static containers and a recirculating system over time.
• Fish were housed in separate static containers and the GeneS individual housing system.
• The study involved standard laboratory procedures for zebrafish housing and water quality testing.

Main Results:

• Static containers showed rapid water quality deterioration, with ammonia levels 25-fold higher than recommended by day 1.
• Nitrite levels exceeded recommended levels for all fish by day 9 in static containers.
• The recirculating GeneS system maintained stable water quality, even with fish feeding.

Conclusions:

• Static housing systems compromise zebrafish welfare due to poor water quality.
• Recirculating water systems or timely water changes are essential for meeting ethical standards in zebrafish housing.
• The GeneS system offers a viable solution for maintaining water quality and supporting fish health.