About the Cover.

Abstract

Next article FreeAbout the CoverPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreCoverWhale sharks (Rhincodon typus) are the largest fish of any kind, and yet relatively little is known about their sensory ecology. Their sheer size makes them intractable subjects for experimental laboratory research, and manipulative studies in the field remain practically impossible. Developments in the public aquarium industry, however, mean that several collections of whale sharks are now available to the research community for investigations under at least quasicontrolled conditions.A compelling question about filter-feeding sharks is how they find suitable patches of food. Mechanisms suggested for the more typical predatory type of shark are less applicable in whale sharks, which feed on plankton. The surface suction-feeding illustrated in the cover image is the most common mode of feeding. During this behavior, the animal adopts a tail-down posture and the top jaw and, importantly, the nares protrude above the water surface where they may be exposed to volatilized chemical cues. Whale sharks have large olfactory lobes in the brain and well-developed nares, which suggests that chemical stimuli (smell or taste) may still play an important role.In seabirds, the volatile chemicals dimethylsulfide (DMS) and dimethylsulfoxide (DMSO) have been shown to initiate food-searching behavior through their positive correlation with plankton abundance and therefore forage fish abundance. In the experiment by A. Dove, described on pages 65–74, plumes of filtered krill extract and DMS were created in an aquarium to investigate whether these chemical cues may also operate in whale sharks. The Georgia Aquarium in Atlanta houses four whale sharks in a 6.3-million-gallon tank with thousands of other fish. The whale sharks responded most strongly to the krill juice mixture, but also showed significant behavioral responses to DMS alone, which suggests that this chemical may play a role in their feeding ecology. With a diverse known diet, however, it is unlikely that a single chemical mediates all feeding responses in whale sharks, and so the quest for deeper understanding of feeding behavior in the world's biggest fish continues.Credits: Photo, Alistair Dove, Georgia Aquarium; layout, Beth Liles, Marine Biological Laboratory. Next article DetailsFiguresReferencesCited by The Biological Bulletin Volume 228, Number 1February 2015 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.1086/BBLv228n1cover © 2015 by Marine Biological Laboratory. All rights reserved.PDF download Crossref reports no articles citing this article.