Spike dives of juvenile southern bluefin tuna (Thunnus maccoyii): a navigational role?
Willis, J and Phillips, J and Muheim, R and Diego-Rasilla, F J and Hobday, AJ (2009) Spike dives of juvenile southern bluefin tuna (Thunnus maccoyii): a navigational role? Behavioral Ecology and Sociobiology, 64 (1). pp. 57-68. ISSN 0340-5443
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Official URL: http://dx.doi.org/10.1007/s00265-009-0818-2
Tunas make sharp descents and ascents around dawn and dusk called spike dives. We examine spike dives of 21 southern bluefin tuna (Thunnus maccoyii) implanted with archival tags in the Great Australian Bight. Using a new way to categorize this behavior, we show that spike dives are similar among all the fish in the study. The dive profiles are mirror images at dawn and dusk and are precisely timed with respect to sunrise and sunset. We analyze the possible reasons for spike dives, considering the timing of spike dives, the characteristic dive profile, and the tuna's magnetic habitat. In addition, we present anatomical evidence for elaboration of the pineal organ, which is light mediated and has been implicated in navigation in other vertebrates. The new evidence presented here leads us to suspect that spike dives represent a survey related to navigation.
|Additional Information:||The original publication is available at www.springerlink.com|
|Keywords:||Migration - Pineal gland - Compass - Magnetic navigation - Polarized light - Archival tags |
|Deposited By:||Ms F Walsh|
|Deposited On:||05 Oct 2009 09:59|
|Last Modified:||25 Jan 2011 13:11|
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