High genetic diversity, large inter‐oceanic divergence and historical demography of the striped mullet

Abstract

The striped mullet Mugil cephalus L. is a circumtropical species whose extreme conservative morphology stands in contrast with the degree of genetic differentiation at a global scale. One hundred and fourteen mitochondrial control region DNA sequences were analysed from four localities in the Gulf of Mexico (Texas, Louisiana, Mississippi, Florida), one on the U.S.A. east coast (N. Carolina), and one in Hawaii, giving very high levels of molecular diversity (h=1·0 every haplotype was unique in all samples, =1·1-2·0% in Gulf-Atlantic and =3·1% in Hawaii). With no genetic evidence of dramatic population expansions, mismatch distributions were still very different in each ocean. Stable population levels in Hawaii have fostered the generation and persistence of very high molecular diversity, but Gulf-Atlantic samples suggest a shorter span of population stability. Ninety-five per cent of the molecular variance was allocated between ocean basins and virtually none among Gulf-Atlantic samples. A neighbourjoining reconstruction revealed Atlantic-and Pacific-specific lineages separated by more than 24% uncorrected sequence divergence (d=0·49 Tamura-Nei Gamma-corrected). The lack of phylogeographic structure among Gulf-Atlantic samples corroborated the AMOVA results and supported the existence of a single population with high levels of gene flow along the Gulf of Mexico and north-west Atlantic coasts. The genetic differentiation between oceans points to the absence of gene flow and an accelerated rate of mitochondrial evolution in the genus Mugil. 2000 The Fisheries Society of the British Isles

Molecular phylogeny of Mugilidae fishes revised

“…Table 4). The divergence observed by other authors in M. cephalus sampled worldwide supports the establishment of a possible speciation (Crosetti et al 1994;Rossi et al 1998a, b;Rocha-Olivares et al 2000). Such distinction is also indicated in the present data where, for instance, significant genetic distances for cytb ranging from 0.0406 to 0.0586 (Table 2) were found in pairwise comparisons among M. cephalus-like haplogroups (Figs.…”

Ancient divergences and recent connections in two tropical Atlantic reef fishes Epinephelus adscensionis and Rypticus saponaceous (Percoidei: Serranidae)

“…Overall, a waveform result may indicate a rapid recovery from a recent genetic bottleneck (Rogers and Harpending 1992). Similar patterns have been observed in other tropical fishes, such as the mullet (Rocha-Olivares et al 2000) and parrotfishes (Dudgeon et al 2000). These data support the growing body of evidence for large-scale instability of marine populations over recent evolutionary time (e.g., Lavery et al 1996;Bowen and Grant 1997;Bucklin and Wiebe 1998;Grant and Bowen 1998;Zane et al 1998).…”

Genetic diversity, population genetic structure, and demographic history of Auxis thazard (Perciformes), Selar crumenophthalmus (Perciformes), Rastrelliger kanagurta (Perciformes) and Sardinella lemuru (Clupeiformes) in Sulu-Celebes Sea inferred by mitochondrial DNA sequences

“…Although the numbers of haplotypes identified were large for all species, genetic differences between haplotypes were considerably low. This high haplotype diversity in concurrence with low nucleotide diversity is also similar with many marine taxa inferred using mtDNA sequence data (Grant and Bowen, 1998;Dudgeon et al, 2000;Rocha-Olivares et al, 2000;Muss et al, 2001;Rocha et al, 2002).…”