Sampling
Data collection and genotyping
Ten individuals of Mullus surmuletus and Diplodus sargus have been sampled all around the Mediterranean coast using a grid of 100 Ă— 100km (an appropriate scale considering fish dispersal distance) that covers the continental shelf of the Mediterranean Sea.
Map of the 100 sampling units of the SEACONNECT project
Samples were collected from fishermen, fish markets or restaurants, after confirming that the fishes had been locally catched. A piece of pectoral or/and tail fins have been gathered and stored in tubes of 95% ethanol to conserve DNA. The sampling has been carried out by several teams of samplers between May and October 2014.
As MPAs are smaller than the chosen resolution of the sampling grid, samples of Diplodus sargus will be collected once again inside the boundaries of some MPAs in 2015.
Pictures of the sampling in a fishing port and a fish market in Turkey
Each fish sampled will be genotyped to provide tens of thousands of Single Nucleotides Polymorphims (SNPs) per individual. Identification of SNPs will be achieved by next generation sequencing using the Genotyping-by-Sequencing (GBS) approach. SNPs became prominent markers for non model species, not only because of their high frequency in the genome, but also because most of them are bi-allelic and have relatively low mutation rates, both factors minimizing homoplasy (similarity of characters not inherited from a common ancestor).
The SNPs will be derived at the Institute for Genomic Diversity at Cornell University.