Common name: Flatfishes

A large and distinctive group of highly compressed bottom-dwelling fishes with more than 800 species. Flatfishes have both eyes on one side of the skull – to the right side of the head in most species.

Larval flatfishes are pelagic, swim upright and are bilaterally symmetrical until one eye migrates over the top of the head during larval development - so that one eye doesn't point down into the sediment once the larvae settle onto the bottom.

Flatfishes are not only asymmetrical in the placement of their eyes, they also have asymmetrical dentition, paired fins and scale coverings. 

During metamorphosis, considerable changes also occur to the head bones, and associated nerves and muscles in readiness for life on the seafloor.

Flatfishes are usually well-camouflaged, matching the soft sediments on which they live. They are ambush predators, often burying themselves leaving only their eyes exposed.

Author: Dianne J. Bray

Cite this page as:
Dianne J. Bray, Flatfishes, PLEURONECTIFORMES in Fishes of Australia, accessed 18 Jul 2024, https://fishesofaustralia.net.au/home/order/36

Order References

Chapleau, F. 1993. Pleuronectiform relationships: a cladistic reassessment. Bulletin of Marine Science 52(1): 516–540 figs 1–7

Cooper, J.A. & Chapleau, F. 1998. Monophyly and intrarelationships of the family Pleuronectidae (Pleuronectiformes), with a revised classification. Fishery Bulletin (U.S.) 69(4): 686–726.

Friedman, M. 2008. The evolutionary origin of flatfish asymmetry 454| 10 July 2008| doi:10.1038/nature07108

Harrington RC, Faircloth BC, Eytan RI, Smith WL, Near TJ, Alfaro ME, Friedman M. 2016. Phylogenomic analysis of carangimorph fishes reveals flatfish asymmetry arose in a blink of the evolutionary eye. BMC Evolutionary Biology 201616:224 DOI: 10.1186/s12862-016-0786-x Open access

Hensley, D.A. & Ahlstrom, E.H. 1984. Pleuronectiformes: relationships. 670–687 in Moser, H.G. et al. (eds). Ontogeny and Systematics of Fishes. American Society of Ichthyologists and Herpetologists. Special Publicaton 1: 1–760

Hoshino, K. 2001. Homologies of the caudal fin rays of Pleuronectiformes (Teleostei). Ichthyological Research 48(3): 231–246

Nelson, J.S. 2006. Fishes of the World. New Jersey : John Wiley & Sons 601 pp.

Norman, J.R. 1934. A Systematic Monograph of the Flatfishes (Heterosomata). Vol. 1. Psettotidae, Bothidae, Pleuronectidae (British Museum (Natural History), London).