Zebrafish, Danio rerio, is a small, tropical, shallowing and highly active cyprinid, widely used in developmental studies and genomics (Fishman, 2001) as well as in toxicity tests on potential aquatic pollutants (Smolders et al., 2002). Basic knowledge on routine metabolic rate in this species is scanty. Here a procedure is presented for quick and reliable evaluation of routine metabolism in zebrafish. Very short acclimation time was necessary. A procedure for evaluation of routine activity during Vo₂ measurements is also reported, based on videorecording and image analysis.

Routine metabolic rate of zebrafish was affected by animal density, temperature and pH. Mean values and variability of oxygen consumption increased when density was lower than 1.5 g per 100 ml. A hypometabolic effect of alkaline pH (9.0) was observed. Critic Po₂ was around 40 torr. Feeding (3% b.w.) induced a 2-3 fold increase in metabolic rate (SDA) within 2-6 h, and lasting up to 24 h, depending on food composition. Routine activity was scarcely affected by any of the conditions tested.

REFERENCES

Fishman, M.C. 2001. Zebrafish - the canonical vertebrate. Science 294, 1290-1291.

Smolders, R., Bervoets, L., De Boeck, G. & Blust, R. 2002. Integrated condition indeces as a measure of whole effluent toxicity in zebrafish (Danio rerio). Environmental Toxigology and Chemistry 21, 87-93.