Loss of genetic variability in a hatchery strain of Senegalese sole (&lt;i&gt;Solea senegalensis&lt;/i&gt;) revealed by sequence data of the mitochondrial DNA control region and microsatellite markers

Pablo Sánchez,Pedro Pablo Ambrosio,Rosa Flos,Jaime R Alvarado Bremer,Jordi Viñas

doi:10.3989/scimar.03232.07e

Abstract

Comparisons of the levels of genetic variation within and between a hatchery F 1 (FAR, n=116) of Senegalese sole, Solea senegalensis , and its wild donor population (ATL, n = 26), both native to the SW Atlantic coast of the Iberian peninsula, as well as between the wild donor population and a wild western Mediterranean sample (MED, n=18), were carried out by characterizing 412 base pairs of the nucleotide sequence of the mitochondrial DNA control region I, and six polymorphic microsatellite loci. FAR showed a substantial loss of genetic variability (haplotypic diversity, h=0.49±0.066; nucleotide diversity, π=0.006±0.004; private allelic richness, pAg=0.28) to its donor population ATL (h=0.69±0.114; π=0.009±0.006; pAg=1.21). Pairwise F ST values of microsatellite data were highly significant (P ST and F ST values between ATL and MED were highly significant (P < 0.0001) with mtDNA CR-I (0.228) and with microsatellite data (0.095), respectively. While loss of genetic variability in FAR could be associated with the sampling error when the broodstock was established, the results of parental and sibship inference suggest that most of these losses can be attributed to a high variance in reproductive success among members of the broodstock, particularly among females.

Highlights

Senegalese sole (Solea senegalensis, Kaup, 1858) is a flatfish of high commercial importance that is indistinguishable by consumers from common sole (S. solea, Linnaeus, 1758), so it is rated as the same species in marketing statistics (Reig et al 2000)
Interest in farming Senegalese sole intensively in southern Europe dates back to the early 1980s, it failed to reach successful commercial development (Imsland et al 2003, Reig et al 2003). The reasons for this include lack of full control over spawning, poor fry quality and high mortality rates during the weaning stage (Cañavate and Fernández-Díaz 1999; Anguís and Cañavate 2005), all leading to juvenile scarcity for stocking purposes. This problem is compounded by a high incidence of skeletal malformations in post-larvae and juveniles (Gavaia et al 2002) and of disease outbursts affecting all ontogenetic stages caused by multiple pathogenic agents (Zorrilla et al 2003)
A total of 160 specimens of S. senegalensis were obtained from the following sources: 1) A farmed sample (FAR, n=116) supplied by an aquaculture operation located in the vicinity of the Ebro River delta (NE coast of Spain) in 2003

Summary

Introduction

Senegalese sole (Solea senegalensis, Kaup, 1858) is a flatfish of high commercial importance that is indistinguishable by consumers from common sole (S. solea, Linnaeus, 1758), so it is rated as the same species in marketing statistics (Reig et al 2000). Interest in farming Senegalese sole intensively in southern Europe dates back to the early 1980s, it failed to reach successful commercial development (Imsland et al 2003, Reig et al 2003) The reasons for this include lack of full control over spawning, poor fry quality and high mortality rates during the weaning stage (Cañavate and Fernández-Díaz 1999; Anguís and Cañavate 2005), all leading to juvenile scarcity for stocking purposes. Optimization of production has not been possible due to high heterogeneity in growth rates within cultured stocks that result in high body size variance at harvest (Dinis et al 1999, Flos et al 2001)

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