Air Breathing Abilities of the Common Carp

Abstract

To prove air breathing, common carps Cyprinus carpio acclimated at 27°C were subjected to the following experiments after a 3h precooling period in water by decreasing the temperature to 17°C. 1) Each fish with a plugged oesophagus was accommodated in a respiratory chamber connected to gas meters for measurements of concentration changes of 02 and C02 at 17°C. 2) Each group of five fish was exposed to 17°C air to examine its 100% survival time. Over time, the Oz concentration decreased and that of C02 increased. The CO2 concentration showed a saturation curve. Mean respiratory rates in the initial period of 1-1.5 h were 51 ± 24.2 m/ 02 perkgh and 24 ± 5.8m/ CO2 perkgh. The 100% survival time with a 3h precooling was 4.5h. As a conclusion, carp breathe following an incomplete COz excretion even in air. © 1994, The Japanese Society of Fisheries Science. All rights reserved.