A realignment of marine biogeographic provinces with particular reference to fish distributions

Abstract

Marine provinces, founded on contrasting floras or faunas, have been recognized for more than 150 years but were not consistently defined by endemism until 1974. At that time, provinces were based on at least a 10% endemism and nested within biogeographic regions that covered large geographic areas with contrasting biotic characteristics. Over time, some minor adjustments were made but the overall arrangement remained essentially unaltered. In many provinces, data on endemism were still not available, or were available only for the most widely studied vertebrates (fishes), a problem that is ongoing. In this report we propose a realignment for three reasons. First, recent works have provided new information to modify or redefine the various divisions and to describe new ones, including the Mid‐Atlantic Ridge, Southern Ocean, Tropical East Pacific and Northeast Pacific. Second, phylogeographic studies have demonstrated genetic subdivisions within and between species that generally corroborated provinces based on taxonomic partitions, with a notable exception at the Indian–Pacific oceanic boundary. Third, the original separation of the warm‐temperate provinces from the adjoining tropical ones has distracted from their close phylogenetic relationships. Here we propose uniting warm‐temperate and tropical regions into a single warm region within each ocean basin, while still recognizing provinces within the warm‐temperate and tropical zones. These biogeographic subdivisions are based primarily on fish distribution but utilize other marine groups for comparison. They are intended to demonstrate the evolutionary relationships of the living marine biota, and to serve as a framework for the establishment of smaller ecological units in a conservation context.

Surgeons and suture zones: Hybridization among four surgeonfish species in the Indo-Pacific with variable evolutionary outcomes

“…Hobbs and Allen (2014) documented 15 pairs of hybridizing species from eight families in this suture zone. Climatic cycles over the past 2 million years have allowed allopatric divergence of Indian and Pacific lineages, which have since come back into contact in this area (Briggs and Bowen, 2012). Another prominent suture zone for reef fishes was recently discovered in the Socotra Archipelago, at the intersection of four biogeographic provinces in the north-western Indian Ocean (DiBattista et al, 2015).…”

“…The Indo-Pacific Barrier (i.e. Sunda Shelf) is ephemeral however, with separate Indian and Pacific Ocean faunas at glacial maxima, followed by a biogeographic gradient during interglacial periods as the two faunas expand into the alternate ocean basin (Briggs and Bowen, 2012;Gaither and Rocha, 2013;Hodge et al, 2014;Eble et al, 2015). Hence, evolutionary divergence between sister taxa may begin at the glacial-induced barrier, but species cohesion depends on maintaining separate gene pools during the interglacial periods of secondary contact (Chenoweth et al, 1998;van Herwerden and Doherty, 2006;Sorenson et al, 2014 (Fig 2c).…”

Genomics of habitat choice and adaptive evolution in a deep-sea fish

“…W hile longitudinal and latitudinal habitat transitions have been proposed to define marine communities and promote intraspecific differentiation [1][2][3] , little is known about the importance of transitions along ocean depth gradients 4,5 , although substantial changes in species assemblages with depth have been recorded (for example, ref. 6 ), and relatively narrow depth ranges may distinguish closely related species (for example, refs 7,8 ).…”

First report of the black gemfish Nesiarchus nasutus (Perciformes: Gempylidae) in Argentinean waters

“…The occasional presences of tropical and subtropical fishes in Argentinean waters are well documented in the literature (Cousseau and Figueroa, 1989;Díaz de Astarloa and Figueroa, 1995;Díaz de Astarloa et al, 2000;Figueroa et al, 2000;Rico and Acha, 2003;Scenna et al, 2006;Solari et al, 2010;Spath et al, 2012;Delpiani et al, 2013). The Argentinean marine biogeographic province (Briggs and Bowen, 2012) is characterized by the encounter between the warm, southward-flowing Brazilian Current, and the cold, northward flow, of the Malvinas Current (Figueroa et al, 1998) and water discharge of continental output (Lucas et al, 2005). There is not clear explanation of how tropical and subtropical fish species arrive to the Argentinean province, but Scenna et al (2006) and Seeliger and Odebrecht (1997) proposed that species of tropical and Antarctic waters might appear sporadically because they use the Brazilian and Malvinas currents as transportation.…”