Meeting Abstract

P2-48   -   Localizing receptors for the magnetic sense in sea turtles Lim, DS*; Goforth, KM; Lohmann, CMF; Lohmann, KJ; University of North Carolina at Chapel Hill ; University of North Carolina at Chapel Hill ; University of North Carolina at Chapel Hill ; University of North Carolina at Chapel Hill d.suling.lim@gmail.com

Diverse animals detect Earth’s magnetic field and use it to guide their movements. Although magnetoreception is phylogenetically widespread, the sensory receptors underlying the magnetic sense have not been unequivocally identified in any animal. One fundamental difficulty is that magnetic fields pass unimpeded through biological tissue, so in principle, magnetoreceptors might be located anywhere in the body. Loggerhead sea turtles (Caretta caretta) are iconic marine migrants with a well-studied ability to use information from Earth’s magnetic field to navigate. To investigate where magnetoreceptors in sea turtles are located, we used a behavioral assay in which young loggerhead turtles were conditioned to respond to a magnetic stimulus. Weak magnets that disrupted the magnetic field over small, localized areas were then attached to different anatomical locations on turtles. The response of turtles to the magnetic stimulus was subsequently observed, with a view toward determining what placement of magnets, if any, disrupted magnetic field detection. Success in localizing magnetoreceptors, even at this general level, will allow us to focus in on potential anatomical structures and sensory mechanisms proposed to underlie magnetoreception.