Passive electroreception in bottlenose dolphins (Tursiops truncatus): implication for micro- and large-scale...

Area of Science:

• Marine Biology
• Sensory Physiology
• Animal Behavior

Background:

• Vibrissal crypts in Guiana dolphins and bottlenose dolphins function as electroreceptors.
• Both dolphin species exhibit sensitivity to weak electric fields.

Purpose of the Study:

• To comparatively assess the electroreceptive sensitivity of bottlenose dolphins.
• Determine detection thresholds for direct current (DC) and alternating current (AC) electric fields in bottlenose dolphins.

Main Methods:

• A psychophysical experiment using the go/no-go paradigm was employed.
• Two bottlenose dolphins were trained to respond to electric field stimuli.

Main Results:

• Bottlenose dolphins detected DC electric fields as low as 2.4 and 5.5 µV cm⁻¹, comparable to other species.
• Detection thresholds for AC fields were higher than DC, decreasing with increasing frequency (1, 5, 25 Hz).

Conclusions:

• Dolphin electroreception, while less sensitive than elasmobranchs, supports micro- and macro-scale orientation.
• Electroreception likely facilitates short-range prey detection and target-oriented feeding in benthic foraging dolphins.
• This sensory modality may enable magnetoreception for large-scale navigation via induction.