The inner ear is responsible for detection of infrasound in the Perch (Perca fluviatilis)

In a previous study of infrasound detection in the cod, the inner ear was suggested to be the sensory organ responsible for the responses. However, a possible involvement of the lateral-line system in the observed low-frequency detection could not be ruled out. The infrasound sensitivity was therefore studied in perch (Perca fluviatilis) with normal and blocked lateral-line organs. The experiments were performed using a standing wave acoustic tube and the cardiac conditioning technique. All perch readily responded to infrasound frequencies down to 0.3Hz with threshold values of approximately 2×10−4ms−2. These thresholds were not affected by complete blocking of the lateral-line system with Co2+, which suggests that the inner ear is responsible for the observed infrasound detection by the perch.