[Control of respiration in teleostean fishes: existence of chemoreceptors, physiologically analogous to those of higher vertebrates].

Injection of NaCN or lobeline into the ventral aorta of the trout or carp provokes hyperventilation and bradycardia within 5 seconds, responses which are the weaker the higher the oxygen tension of the ambient water. The reactions, precisely similar to the chemoreflexes of higher vertebrates, suggest that these fish also possess arterial chemoreceptors.