title: Depth-dependent swimbladder compression in herring Clupea harengus observed using magnetic resonance imaging.
abstract: Changes in swimbladder morphology in an Atlantic herring Clupea harengus with pressure were examined by magnetic resonance imaging of a dead fish in a purpose-built pressure chamber. Swimbladder volume changed with pressure according to Boyle's Law, but compression in the lateral aspect was greater than in the dorsal aspect. This uneven compression has a reduced effect on acoustic backscattering than symmetrical compression and would elicit less pronounced effects of depth on acoustic biomass estimates of C. harengus.
authors.affiliation: Gatty Marine Laboratory, University of St Andrews, St Andrews, Fife, KY16 8LB, Scotland, UK. s.faessler@marlab.ac.uk
authors.forename: S M M
authors.initials: SM
authors.lastname: Fässler
authors.forename: P G
authors.initials: PG
authors.lastname: Fernandes
authors.forename: S I K
authors.initials: SI
authors.lastname: Semple
authors.forename: A S
authors.initials: AS
authors.lastname: Brierley
mesh_terms: D000400:Air Sacs / Q000502:physiology*; D000818:Animals; D005399:Fishes / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D011312:Pressure