How long can rats hold their breath? - briefly
Rats typically remain underwater for 30 seconds to 2 minutes, with the upper limit observed in trained or submerged conditions. The exact duration varies with age, health, and environmental temperature.
How long can rats hold their breath? - in detail
Rats display a brief apnea capability that varies with species, age, and experimental conditions. Laboratory studies on the common laboratory rat (Rattus norvegicus) report maximum submersion times between 30 seconds and 2 minutes when the animal is not trained for diving. Young adult individuals typically sustain breath-holding for 45–60 seconds under cold‑water immersion (4 °C) and for 70–90 seconds in room‑temperature water (22 °C).
Factors influencing the duration include:
- Body temperature: lower temperatures reduce metabolic rate and extend apnea.
- Oxygen reserves: higher hemoglobin concentration and lung volume increase available oxygen.
- Training: rats conditioned to dive repeatedly can exceed 2 minutes, showing physiological adaptation similar to aquatic mammals.
- Stress level: elevated cortisol suppresses respiratory drive, shortening breath‑holding time.
Physiological mechanisms involve a rapid shift to anaerobic metabolism, utilization of stored oxygen in blood and muscle myoglobin, and a delayed chemoreceptor response to rising carbon‑dioxide levels. The dive reflex triggers bradycardia, peripheral vasoconstriction, and splenic contraction, which together conserve oxygen for vital organs.
Comparative data indicate that the brown rat’s apnea limit is shorter than that of the water vole (Arvicola amphibius), which can remain submerged for up to 3 minutes, but longer than the house mouse (Mus musculus), whose typical limit is 20–30 seconds.
«Experimental observations suggest that the upper bound for untrained rats approaches 2 minutes, while trained individuals may achieve slightly longer periods under controlled conditions».