Population subdivision of saddled seabream Oblada melanura in the Aegean Sea revealed by genetic and morphometric analyses

Abstract

The population structure of marine fishes is often cryptic, due to limited knowledge about life history and ecological habitats. Understanding environmental stability is a challenge to retrieve possible structuring patterns responsible for dispersal and demographic habits. In the present study, a combination of genetic and phenotypic assessments was applied in order to investigate population structure of the saddled seabream Oblada melanura in the Aegean Sea, eastern Mediterranean basin. Analyses of 6 microsatellite loci and 15 morphometric characters revealed that saddled seabream individuals differ among northern, southern and central Aegean populations. These observed boundaries may be related to the differentiated seascape of the Aegean Sea, suggesting that oceanographic factors are a significant stressor for population subdivision of the saddled seabream. Individual-based landscape genetic approaches and multivariate analysis of the morphometric characters suggest the presence of habitat-related limitations of saddled seabream dispersal potential. Molecular genetics and phenotypic analyses along with life-history traits provide useful informative data for the management and conservation schemes applied for this species in the Aegean Sea.KEY WORDS: Oblada melanura · Microsatellite · Morphometrics · Aegean Sea · Population structure Resale or republication not permitted without written consent of the publisher

Spatial genetic structure in the saddled sea bream (Oblada melanura [Linnaeus, 1758]) suggests multi-scaled patterns of connectivity between protected and unprotected areas in the Western Mediterranean Sea

“…Similar results were recorded, for the same species, using a different set of microsatellite primers (Gkafas et al, 2013), and in other sparid fish in the Mediterranean Sea (Franchini et al, 2011). High genetic diversity is fundamental for maintaining the adaptability of natural fish populations and sustainable yields in fisheries (Kenchington et al, 2003).…”

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“…Güven (2011) reported that abyssal gradients have also an effect on gene flow of Sepia officinalis in the North-West Levantine region. There are subdivisions found between saddled seabream Oblada melanura populations in North Aegean Sea which might be the reason of a deep trench of 1500 m, presenting a physical geographical boundary in the Central Aegean (Gkafas et al, 2013). In the present study, the samples from LSK population were collected from a lagoon which has a more than 4000 meters deep trench (Rhodes Abyssal Plain) just starting from the shore.…”

Do the Fish Scales Shape of Mugil curema Reflect the Genetic Structure Using Microsatellites Markers and the Mexican Marine Ecoregions Classification?

“…Ocean circulation acts as a barrier to the dispersal of larvae and leads to genetic structuring (Karlsson et al, 2009;Castillo-Olguín et al, 2012;Prieto-Ríos et al, 2014) and morphological differentiation (AnvariFar et al, 2013;Gkafas et al, 2013). The morphological variability recorded among different localities or geographic variants may be due to the genetic structure or to differences in the environmental conditions that prevail in each geographic area.…”