Phylogeography of Ophioblennius: The Role of Ocean Currents and Geography in Reef Fish Evolution

Abstract

Many tropical reef fishes are divided into Atlantic and East Pacific taxa, placing similar species in two very different biogeographic regimes. The tropical Atlantic is a closed ocean basin with relatively stable currents, whereas the East Pacific is an open basin with unstable oceanic circulation. To assess how evolutionary processes are influenced by these differences in oceanography and geography, we analyze a 630-bp region of mitochondrial cyto-chrome b from 171 individuals in the blenniid genus Ophioblennius. Our results demonstrate deep genetic structuring in the Atlantic species, O. atlanticus, corresponding to recognized biogeographic provinces, with divergences of d 5.2-12.7% among the Caribbean, Brazilian, St. Helena/Ascension Island, Gulf of Guinea, and Azores/Cape Verde regions. The Atlantic phylogeny is consistent with Pliocene dispersal from the western to eastern Atlantic, and the depth of these separations (along with prior morphological comparisons) may indicate previously unrecognized species. The eastern Pacific species, O. steindachneri, is characterized by markedly less structure than O. atlanticus, with shallow mitochondrial DNA lineages (d max 2.7%) and haplotype frequency shifts between locations in the Sea of Cortez, Pacific Panama, Clipperton Island, and the Galapagos Islands. No concordance between genetic structure and biogeographic provinces was found for O. steindachneri. We attribute the phylogeographic pattern in O. atlanticus to dispersal during the reorganization of Atlantic circulation patterns that accompanied the shoaling of the Isthmus of Panama. The low degree of structure in the eastern Pacific is probably due to unstable circulation and linkage to the larger Pacific Ocean basin. The contrast in genetic signatures between Atlantic and eastern Pacific blennies demonstrates how differences in geology and oceanography have influenced evolutionary radiations within each region.

Molecular phylogenetics and biogeography of transisthmian and amphi-Atlantic needlefishes (Belonidae: Strongylura and Tylosurus): perspectives on New World marine speciation

“…regalis group (Banford et al, 1993). In general, however, our findings and those of others (Lessios et al, 1999(Lessios et al, , 2000Muss et al, 2001;Scheltema, 1973Scheltema, , 1995 do not fully support RosenÕs hypothesis for relationships of New World to eastern Atlantic faunas and the timing of these events. Specifically as an example, the relationship of S. timucu and S. senegalensis indicates a very recent separation of transAtlantic species and includes the possibility of dispersal playing a central role.…”

“…As noted previously, our analyses do not permit us to resolve the geographic placement of the S. timucu ancestor. An amphi-Atlantic ancestor would argue for continued gene flow across the Atlantic Ocean until very recently (see Muss et al, 2001), whereas a western Atlantic ancestor would presuppose that the genus Strongylura went extinct or was never present in the eastern Atlantic prior to or coincident with the recent trans-Atlantic dispersal event suggested by the molecular data.…”

Phylogenetic analysis of Peri-Mediterranean blennies of the genus Salaria: Molecular insights on the colonization of freshwaters

“…Unfortunately, there are no other species pairs of blenniids distributed on both sides of the isthmus to undertake a more accurate calibration. Muss et al (2001) compared the cytochrome b of species of Ophioblennius, a genus that occurs in the tropical Atantic and the eastern tropical Pacific. They found that even the divergence among different Atlantic populations started well before the separation of the two oceans.…”

Molecular systematics, historical ecology, and phylogeography of Halimeda (Bryopsidales)

“…Widespread occurrence of extant species, even on remote archipelagos (e.g., Drew, 1995;Hillis-Colinvaux, 1980Taylor, 1950;Tsuda and Kamura, 1991;Tsuda and Wray, 1977) and pan-tropical patterns of fossil ones prior to the vicariant events (Elliott, 1981;Fl€ u ugel, 1988) suggest long-distance dispersal. Such dispersal in marine organisms is considered to be a function of larval endurance in the plankton, active migrating or drifting capability, (ir)-regularity of ocean current patterns, seawater temperature tolerance limits, and habitat availability (seaweeds: Prud'homme van Reine and Van den Hoek, 1988, 1990Van den Hoek, 1987, corals: Veron, 1995, fish: Bowen et al, 2001Colborn et al, 2001;Muss et al, 2001, and sea urchins: Lessios et al, 1999Lessios et al, , 2001. Although calcified thalli of Halimeda are unlikely drifters, uncalcified juvenile stages, which grow slowly for extended periods (Meinesz, 1980), could hitchhike across the ocean on drift material (Woelkerling, 1975).…”