Use of electroreception during foraging by the Australian lungfish

Area of Science:

• Comparative physiology
• Sensory biology
• Neuroethology

Background:

• Passive electroreception is a key sensory modality for prey detection in various aquatic animals, including elasmobranchs and nonteleost fish.
• The Australian lungfish (Neoceratodus forsteri) possesses ampullary electroreceptors and associated brain pathways, suggesting a potential electric sense for foraging.

Purpose of the Study:

• To investigate whether Neoceratodus forsteri utilizes passive electroreception for locating hidden prey.
• To quantify the role of electrical versus olfactory cues in the lungfish's prey-detection behavior.

Main Methods:

• Characterized feeding behavior of N. forsteri towards a hidden crayfish (Cherax destructor) in a substrate chamber.
• Manipulated sensory cues by presenting live prey with intact or shielded bioelectric fields, and controlled for olfactory and mechanical stimuli.
• Assessed lungfish feeding responses under conditions with and without competing olfactory signals.

Main Results:

• N. forsteri exhibited accurate and sustained feeding movements towards live crayfish emitting bioelectric fields, even with a competing olfactory stimulus.
• Abolishing electrical cues significantly reduced the accuracy and frequency of feeding movements in control treatments (shielded prey, dead prey, empty chamber).
• Lungfish demonstrated a clear preference and ability to locate prey based on electrical signals.

Conclusions:

• Neoceratodus forsteri possesses the capacity to perceive weak bioelectric fields generated by living prey.
• Passive electroreception is a crucial sensory mechanism for N. forsteri when foraging for concealed prey.
• This study provides direct evidence for the functional use of electroreception in lungfish prey location.