Three-dimensional post-glacial expansion and diversification of an exploited oceanic fish

Shum, P; Pampoulie, C; Kristinsson, K; Mariani, S

Abstract

Vertical divergence in marine organisms is being increasingly documented, yet much remains
to be done to understand the role of depth in the context of phylogeographic reconstruction
and the identification of management units. An ideal study system to address this issue is the
beaked redfish, Sebastes mentella – one of four species of “redfish” occurring in the North
Atlantic – which is known for a widely-distributed “shallow-pelagic” oceanic type inhabiting
waters between 250 and 550m, and a more localised “deep-pelagic” population dwelling
between 550 and 800m, in the oceanic habitat of the Irminger Sea. Here, we investigate the
extent of population structure in relation to both, depth and geographic spread of oceanic
beaked redfish throughout most of its distribution range. By sequencing the mitochondrial
control region of 261 redfish collected over a decadal interval, and combining 160 rhodopsin
coding nuclear sequences and previously genotyped microsatellite data, we map the existence
of two strongly divergent evolutionary lineages with significantly different distribution
patterns and historical demography, and whose genetic variance is mostly explained by depth.
Combined genetic data, analysed via independent approaches, are consistent with a late
Pleistocene lineage split, where segregation by depth likely resulted from the interplay of
climatic and oceanographic processes with life-history and behavioural traits. The on-going
process of diversification in North Atlantic S. mentella may serve as an “hourglass” to
understand speciation and adaptive radiation in Sebastes and in other marine taxa distributed
across a depth gradient.

• Journal Article Type: Article
• Acceptance Date: May 29, 2015
• Online Publication Date: Jun 14, 2015
• Publication Date: Jul 15, 2015
• Deposit Date: Jun 8, 2015
• Publicly Available Date: Apr 5, 2016
• Journal: Molecular Ecology
• Print ISSN: 0962-1083
• Electronic ISSN: 1365-294X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 24
• Issue: 14
• Pages: 3652-3667
• DOI: https://doi.org/10.1111/mec.13262
• Publisher URL: http://dx.doi.org/10.1111/mec.13262
• Related Public URLs: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291365-294X
• Additional Information: Projects : Oceans in 3D: adaptation to divergent depth environments in an oceanic fish