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The common dentex, Dentex dentex, is a fish species which inhabits marine environments in the Mediterranean and Northeast Atlantic regions. This is an important species from an ecological, economic and conservation perspective, however critical information on its population genetic structure is lacking. Most samples were obtained from the Mediterranean Sea (17 sites) with an emphasis around Corsica (5 sites), plus one Atlantic Ocean site. This provided an opportunity to examine genetic structuring at local and broader scales to provide science based data for the management of fishing stocks in the region. Two mitochondrial regions were examined (D-loop and COI) along with eight microsatellite loci. The COI data was combined with publicly available sequences and demonstrated past misidentification of common dentex. All markers indicated the absence of population genetic structure from the Bay of Biscay to the eastern Mediterranean Sea. Bayesian approaches, as well as the statistical tests performed on the allelic frequencies from microsatellite loci, indicated low differentiation between samples; there was only a slight (p = 0.05) indication of isolation by distance. Common dentex is a marine fish species with a unique panmictic population in the Mediterranean and likely in the Atlantic Ocean as well.

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The last decade period has been characterized by a remarkable increase in the need for food, bioenergy, and pharmaceutical compounds. Meanwhile, microalgae have been in the center of interest as a rich and sustainable source of highly valuable natural products and bioactive compounds. In this perspective, the present study aimed at investigating the biochemical composition of 10 cyanobacterial strains collected from several Tunisian inland waters, seeking to identify the possible use of cyanobacteria in nutraceuticals and pharmaceuticals industry, and for animal and human consumption. Ten local strains of cyanobacteria were isolated from several Tunisian inland waters and cultured in controlled laboratory conditions. Fatty Acid methyl esters were analyzed in each strain by Gas chromatography-Mass spectrometry (GC-MS) as well as total proteins, carbohydrates and different phycobiliproteins (phycocyanin, allophycocyanin and phycoerythrin). Results showed that Planktothrix agardhii, Leptolyngbya sp1., and Leptolyngbya sp2. contained 14 different fatty acids, among which oleic acid was the most abundant. These might be important in nutraceutical and agronomic sectors due to the potent antioxidant and larvicidal activities of oleic acid. Cylindrospermopsis raciborskii presents extraordinarily high levels of phycocyanin, making it an exceptional natural reservoir of effective and non-toxic drugs that are of particular interest against cancer and neurodegenerative diseases. Extracts from cyanobacterial strains represent a natural and available source of proteins, of highly valuable fatty acids, and especially of phycocyanin which is known by its extremely health beneficial properties. The nutritional and functional complements provided by these extracts can be used in the prevention of various diseases and also as effective and environmentally friendly insecticides.

With its 1300 km coastline and 110 000 ha of coastal lagoons, Tunisia offers important resources to demersal and pelagic fisheries. Among all the exploited fish species in Tunisia, mugilids are the most widespread. They are known in temperate, subtropical and tropical regions, and occur both in coastal areas, lagoon ecosystems and inland waters. Six mugilids species have been inventoried in Tunisia. Their migratory behavior consists of moving back and forth between brackish and saline environment where they spend a large part of their life cycles. This behavior results in a peculiar high vulnerability to human pressure. Consequently, they require special attention from fisheries managers for sustainable catches. This study was based on the data from the national fishing and aquaculture directorate (DGPA) statistics, and comprised time series from 1995 to 2015. We looked for clear tendencies and correlations between harvest from the coastal sea and lagoons of the different coastal regions, in relation to recruitment in coastal marine waters. We focused on two species, i.e. Mugil cephalus and Liza aurata, which are best appreciated for local consumption and, therefore, most targeted by the fishery in Tunisia. The Tunisian lagoons show a decreasing trend in mugilids landings. This may be explained by the disturbance of migratory ways and the degradation of the coastal habitats, by the harvest of fry used for the inland water-stocking program, and by the multiplication of droughts. Particularly the latter strongly limits the migration of juveniles. The harvest in the coastal zones is relatively stable, follows perfectly the total national landings, with although a clear increase since 2011 as a result of uncontrolled illegal fishing. The negative correlation between the total harvests of mugilids in the coastal sea and coastal lagoon was highly significant (Pearson coefficient r = −0.702, p < 0.001).

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