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Machnik P, Leupolz K, Feyl S, Schulze W, Schuster S. The Mauthner cell in a fish with top-performance and yet flexibly tuned C-starts. I. Identification and comparative morphology. ACTA ACUST UNITED AC 2018; 221:jeb.182535. [PMID: 29789403 DOI: 10.1242/jeb.182535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/15/2018] [Indexed: 10/16/2022]
Abstract
Archerfish use two powerful C-starts: one to escape threats, the other to secure prey that they have downed with a shot of water. The two C-starts are kinematically equivalent and variable in both phases, and the predictive C-starts - used in hunting - are adjusted in terms of the angle of turning and the final linear speed to where and when their prey will hit the water surface. Presently, nothing is known about the neural circuits that drive the archerfish C-starts. As the starting point for a neuroethological analysis, we first explored the presence and morphology of a pair of Mauthner cells, which are key cells in the teleost fast-start system. We show that archerfish have a typical Mauthner cell in each medullary hemisphere and that these send by far the largest axons down the spinal cord. Stimulation of the spinal cord caused short-latency all-or-none field potentials that could be detected even at the surface of the medulla and that had the Mauthner cell as its only source. The archerfish's Mauthner cell is remarkably similar morphologically to that of equally sized goldfish, except that the archerfish's ventral dendrite is slightly longer and its lateral dendrite thinner. Our data provide the necessary starting point for the dissection of the archerfish fast-start system and of any role potentially played by its Mauthner cell in the two C-start manoeuvres. Moreover, they do not support the recently expressed view that Mauthner cells should be reduced in animals with highly variable fast-start manoeuvres.
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Affiliation(s)
- Peter Machnik
- Department of Animal Physiology, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Kathrin Leupolz
- Department of Animal Physiology, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Sabine Feyl
- Department of Animal Physiology, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Wolfram Schulze
- Department of Animal Physiology, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Stefan Schuster
- Department of Animal Physiology, University of Bayreuth, D-95440 Bayreuth, Germany
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Nishiumi N, Matsuo A, Kawabe R, Payne N, Huveneers C, Watanabe YY, Kawabata Y. A miniaturized threshold-triggered acceleration data-logger for recording burst movements of aquatic animals. ACTA ACUST UNITED AC 2018; 221:jeb.172346. [PMID: 29444848 DOI: 10.1242/jeb.172346] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/03/2018] [Indexed: 12/26/2022]
Abstract
Although animal-borne accelerometers are effective tools for quantifying the kinematics of animal behaviors, quantifying the burst movements of small and agile aquatic animals remains challenging. To capture the details of burst movements, accelerometers need to sample at a very high frequency, which will inevitably shorten the recording duration or increase the device size. To overcome this problem, we developed a high-frequency acceleration data-logger that can be triggered by a manually defined acceleration threshold, thus allowing the selective measurement of burst movements. We conducted experiments under laboratory and field conditions to examine the performance of the logger. The laboratory experiment using red seabream (Pagrus major) showed that the new logger could measure the kinematics of their escape behaviors. The field experiment using free-swimming yellowtail kingfish (Seriola lalandi) showed that the loggers trigger correctly. We suggest that this new logger can be applied to measure the burst movements of various small and agile animals.
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Affiliation(s)
- Nozomi Nishiumi
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852-8521, Japan.,Institute for East China Sea Research, Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1551-7 Tairamachi, Nagasaki 851-2213, Japan
| | - Ayane Matsuo
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852-8521, Japan
| | - Ryo Kawabe
- Institute for East China Sea Research, Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1551-7 Tairamachi, Nagasaki 851-2213, Japan
| | - Nicholas Payne
- University of Roehampton, Holybourne Avenue, London SW15 4JD, UK
| | - Charlie Huveneers
- College of Science and Engineering, Flinders University, SA 5042, Australia
| | - Yuuki Y Watanabe
- National Institute of Polar Research, Tachikawa, Tokyo 190-8518, Japan.,SOKENDAI (The Graduate University for Advanced Studies), Tachikawa, Tokyo 190-8518, Japan
| | - Yuuki Kawabata
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852-8521, Japan .,Institute for East China Sea Research, Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1551-7 Tairamachi, Nagasaki 851-2213, Japan
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