Skip to main content

Research Repository

Advanced Search

Hydrodynamic and phylogenetic aspects of the adipose fin in fishes

Reimchen, T. E.; Temple, N. F.

Authors

T. E. Reimchen

N. F. Temple



Abstract

The adipose fin on fishes is a highly conserved and enigmatic, small, non-rayed fin that has persisted from the Mesozoic on some basal teleosts such as salmonids. Using juvenile steelhead, Oncorhynchus mykiss (Walbaum, 1792), ranging from 5 to 18 cm standard length, we experimentally test the effects of adipose fin removal on swimming performance in a variable velocity flow chamber and quantify, with seven independent trials, amplitude and frequency of caudal fin movement at multiple flow velocities (range 10-39 cm.s-1). Results demonstrate that adipose fin removal on smolts produces an average 8% (range -3% to 23%) increase in caudal fin amplitude relative to unclipped fish across all velocities. However, we observed no effects in trials with smaller fish (12 cm). Consistent with speculations in the literature, our results show that the adipose fin may function to control vortices enveloping the caudal fin during swimming or, alternatively, function as a passive precaudal sensor of turbulent flow. Phylogenetic persistence of this trait among multiple groups of early bony fishes is probably due to its hydrodynamic attributes rather than developmental constraints, and the current widespread practice in fisheries of removing the adipose fin as a marking technique may have significant biological costs.

Citation

Reimchen, T. E., & Temple, N. F. (2004). Hydrodynamic and phylogenetic aspects of the adipose fin in fishes. Canadian Journal of Zoology, 82(6), 910-916. https://doi.org/10.1139/Z04-069

Journal Article Type Article
Acceptance Date May 21, 2004
Publication Date Jun 1, 2004
Deposit Date Jun 18, 2019
Publicly Available Date Mar 28, 2024
Journal Canadian Journal of Zoology
Print ISSN 0008-4301
Publisher Canadian Science Publishing
Peer Reviewed Peer Reviewed
Volume 82
Issue 6
Pages 910-916
DOI https://doi.org/10.1139/Z04-069
Keywords vestigial trait, salmonid, adipose fin, swimming dynamics, fish phylogeny
Public URL https://uwe-repository.worktribe.com/output/1494854
Publisher URL https://doi.org/10.1139/z04-069