Electric field detection in sawfish and shovelnose rays

Barbara E. Wueringer, Lyle Squire Jnr, Stephen M. Kajiura, Ian R. Tibbetts, Nathan S. Hart, Shaun P. Collin

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)
40 Downloads (Pure)


In the aquatic environment, living organisms emit weak dipole electric fields, which spread in the surrounding water. Elasmobranchs detect these dipole electric fields with their highly sensitive electroreceptors, the ampullae of Lorenzini. Freshwater sawfish, Pristis microdon, and two species of shovelnose rays, Glaucostegus typus and Aptychotrema rostrata were tested for their reactions towards weak artificial electric dipole fields. The comparison of sawfishes and shovelnose rays sheds light on the evolution and function of the elongated rostrum ('saw') of sawfish, as both groups evolved from a shovelnose ray-like ancestor. Electric stimuli were presented both on the substrate (to mimic benthic prey) and suspended in the water column (to mimic free-swimming prey). Analysis of around 480 behavioural sequences shows that all three species are highly sensitive towards weak electric dipole fields, and initiate behavioural responses at median field strengths between 5.15 and 79.6 nVcm-1. The response behaviours used by sawfish and shovelnose rays depended on the location of the dipoles. The elongation of the sawfish's rostrum clearly expanded their electroreceptive search area into the water column and enables them to target free-swimming prey.

Original languageEnglish
Article numbere41605
Pages (from-to)1-8
Number of pages8
JournalPLoS ONE
Issue number7
Publication statusPublished - 25 Jul 2012
Externally publishedYes

Bibliographical note

Copyright the Author(s) 2012. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


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