Environmental features of deep‐sea habitats linked to the genetic population structure of a crustacean species in the Mediterranean Sea

Abstract

The deep-sea habitat, from 200 to 2000 m depth, has long been thought as an ecosystem where biotic and abiotic factors vary very little and consequently species are not disturbed by processes and phenomena which could promote fast evolutionary mechanisms. Unfortunately, biological information relating to deep water is limited, especially regarding the population genetics of species inhabiting the Mediterranean Sea, and general patterns cannot be inferred. In this study we report data on the population genetic structure of Aristeus antennatus, a deep-sea decapod crustacean species which has been widely studied due to its important economic value. We surveyed and examined the variation in a 369-bp fragment of the mtDNA control region from individuals caught by Spanish and Italian trawlers in eight localities. High levels of mitochondrial control region haplotypic diversity (ranging from 0.884 to 0.989) were observed. AMOVA showed a high level of genetic variation, more within than between populations, and a low but significant ΦST value was recovered. Minimum spanning network did not separate any haplotype group and haplotype distribution does not mirror the geographic origin of the samples. The absence of population substructuring was also observed with a principal coordinates analysis, which uses an individual-by-individual comparison. These results revealed extensive gene flow among populations. Information on demographic history based on mismatch analysis revealed an unstable population, showing an alternate pattern of growth and decline. Our results indicated that in the western and central Mediterranean basins A. antennatus is a large panmictic population with a fluctuating abundance. The absence of deep-sea barriers and adult migration may prevent the structuring of the species into genetically differentiated populations

Growth Parameters and Population Structure of Aristeus Antennatus (Decapoda, Penaeidae) in the South Tyrrhenian Sea (Southern Coast of Italy)

“…According to Guijarro et al (2008) and references therein, the importance of water mass movements in size distribution and abundance of blue and red shrimp is indisputable. The same observation was also reported by Maggio et al (2009), who analysed the genetic variation in this species in different parts of the Mediterranean Sea; in particular, those authors did not find any significant difference between the samples and hypothesized, as also reported by Cartes et al (2008), that such genetic homogeneity is strictly correlated with: (i) the biological characteristics of this species; (ii) the horizontal and vertical fluctuations of the water masses; and (iii) the spatio-temporal variations in the chemical/physical factors and the trophic resources. Of course, it is important that further ad hoc oceanographic investigations are undertaken to verify whether or not these differences between our sample sites are linked to environmental conditions.…”

“…Considering its high economic value, the blue and red shrimp has been the object of numerous research studies addressing their reproductive cycle (Arculeo et al, 1995 and references therein), catch estimations, ecology, population structure (Demestre & Lleonart, 1993;Fiorentino et al, 1998;Cau et al, 2002;Sardà et al, 2004;D'Onghia et al, 2005;Arculeo, 2008;Guijarro et al, 2008), and more recently genetic variation (Roldan et al, 2008;Maggio et al, 2009). Investigations on both population and genetic structure can contribute to the knowledge of, for example, whether or not the species is overexploited and whether or not it is represented by different unit stocks; knowledge that may provide useful information in recovery programmes or other management activities.…”

Influence of the genetic structure of the red and blue shrimp, <i>Aristeus antennatus</i> (Risso, 1816), on the sustainability of a deep-sea population along a depth gradient in the western Mediterranean

“…Table 2). Furthermore, haplotype diversity values calculated in the present work and those in Roldán et al (2009) were substantially lower than values obtained by Maggio et al (2009) in eight Mediterranean samples of Aristeus antennatus (h = 0.884 to 0.989) analyzed by means of sequencing of a 369 bp portion of the mitochondrial control region, the maximum value being obtained for the Catalan Sea sample (N = 14). This difference accounts for the well-known higher mutation rate of the control region in comparison with the 16S gene.…”

Climate change and population genetic structure of marine species

“…(Right) Examples of the respective models in Mediterranean species. (a) Panmixia: blue-red shrimp Aristeus antennatus sampled in the western and central Mediterranean Sea showed an absence of population structure as evidenced by the distribution of the mitochondrial haplotypes [79]. (b) Discrete subpopulations: the gobid Pomatoschistus tortonesei showed a strong genetic partition between the western (W) and eastern Mediterranean (E) sub-basin, revealing the Siculo-Tunisian Strait (STS) as a hydrographic barrier to gene flow [30].…”