Type
ArticleKAUST Department
Biological and Environmental Sciences and Engineering (BESE) DivisionMarine Science Program
Date
2014-10-22Permanent link to this record
http://hdl.handle.net/10754/555653
Metadata
Show full item recordAbstract
Jellyfish blooms occur in marine environments around the world and have been linked to over-fishing, eutrophication and climatic change. In some coastal areas of Norway, the circumglobal Periphylla periphylla has increased to exceptionally high abundances and has replaced fish as the main planktivorous predator despite the ineffectiveness of its non-visual predation compared to visual fish predation. Using data from a bottom-mounted acoustic platform, we collected 12341 in situ measurements of individual vertical movements of large individuals of P. periphylla. These jellyfish are characterized by a stepwise vertical movement. The distribution of their vertical swimming distances was extremely left skewed; about 85% of the swimming distances were less than 3 m, and a few displacements were extremely long with a maximum of 85 m. Chi-square tests of goodness of fit to the tail and Akaike’s information criterion gave overwhelming evidence of the truncated power law. There was a clear diel pattern in the exponent with values significantly larger than 3 during the daytime and significantly lower than 3 at night. This pattern means that P. periphylla switches from relatively limited movements during the day to Lévy-like flights during the night. Since the abundance of zooplankton is large in the P. periphylla fjord, Brownian motion, rather than Lévy flight, is predicted by the optimal foraging hypothesis. It is therefore possible that the Lévy-like search pattern has evolved in the food-scarce oceanic environment, which is the main natural habitat of P. periphylla. Alternatively, the large individuals of the population addressed here may forage on scarcer prey sources than the main prevailing zooplankton in Lurefjorden.Citation
Lévy night flights by the jellyfish Periphylla periphylla 2014, 513:121 Marine Ecology Progress SeriesPublisher
Inter-Research Science CenterJournal
Marine Ecology Progress SeriesAdditional Links
http://www.int-res.com/abstracts/meps/v513/p121-130/ae974a485f413a2113503eed53cd6c53
10.3354/meps10942