Passive electroreception in aquatic mammals.
Level 5 - mechanism / opinion, no new human data
Narrative review of comparative animal physiology and anatomy (graded by design analogy).
PubMed 23187861 · doi:10.1007/s00359-012-0780-8
What was done
The authors reviewed published evidence on the morphology, function, and evolutionary origin of passive electroreceptors in aquatic mammals, specifically focusing on the platypus (Ornithorhynchus anatinus) and the Guiana dolphin (Sotalia guianensis).
What was found
The abstract reports no exact numeric values. It states that electroreceptive detection thresholds between the platypus and Guiana dolphin fall within one order of magnitude. Both species utilize electroreception for foraging in low-visibility conditions or substrate digging, and both have electroreceptors innervated by the trigeminal nerve that resemble ampullary electroreceptors in fish. However, their structural origins differ completely: platypus electroreceptors evolved from skin glands, whereas Guiana dolphin electroreceptors derived from the vibrissal system.
Why it matters
The paper demonstrates convergent sensory evolution in mammals, showing how distinct anatomical precursors can evolve into functionally similar electroreceptive systems to support foraging in turbid aquatic environments.
Limits
The abstract provides a narrative overview without reporting exact sensory thresholds, sample sizes, search methodology, or primary experimental data. Generalizations are limited to two specific aquatic mammal lineages.
Cited by
- contradicts The platypus emits electrical fields from its bill to detect objects in its environment.