The source of DNA are gills and possibly other tissues preserved in alcohol. The main markers involved are microsatellites. Tri and tetra nucleotides were isolated to avoid sub-banding problems, which are evident with the more commonly used and abundant dinucleotide. Modern enrichment methods were utilised to achieve this. Five or more variable micro loci utilisable in each species, then other markers such as mt DNA, PCRable minisatellites and transcribed sequences, were investigated, since each have specific advantages in stock discrimination.

Results from this task revealed major differences between species in the extent of stock structuring. Results from screening over the range of Illex coindetii and Todaropsis eblanae for four and two loci respectively, demonstrate significant discontinuities.