WP7

Lead Partner

Antonio Villalba

Procedures for developing cockle culture, supporting genetic breeding programs for resistance to marteiliosis

Responsible partner

Consellería do Mar, Xunta de Galicia · CIMA-XUGA | ES

Cost-effective procedures will be settled to produce cockle seed in hatchery facilities and to grow the seed outdoor up to market size, minimising the impact on the ecosystem. The knowledge currently applied to successfully culture other bivalve molluscs species will be used. The required research on reproduction, nutrition, growth and zootechnical aspects will be performed for every culture stage, indoor (hatchery) and outdoor (two ways: suspended culture and culture in bottom plots).

A marteiliosis outbreak occurs every year in some Galician bays, devastating new recruitment. A search for cockle protein markers of resistance to marteiliosis will be performed. The proteins of the cockle blood cells and those of the digestive gland will be involved in this search; the blood cells because they are main characters of cockle immune reactions and the digestive gland because the parasite causing marteiliosis multiplies in this organ. The set of proteins of cockles surviving a marteiliosis outbreak will be compared with that of cockles taken before the outbreak occurs; the proteins being more abundant in survivors will be identified and evaluated as putative markers of resistance to marteiliosis.

There have to be cockle genes playing key roles to control marteiliosis. The expression of genes related to immunity will be scrutinised in cockles harvested along a marteiliosis outbreak, including survivors. Thus, genes with varying expression associated with this disease will be detected; a search for identifying allelic variants exclusive of survivors among those genes will be performed. Those variants will be evaluated as putative markers of resistance to marteiliosis.

The integration of the complementary information on proteins and genes from actions 7.2 and 7.3, respectively, will provide key knowledge to understand the molecular basis for controlling marteiliosis. The markers of resistance identified in those actions together with the information on hatchery production of cockle seed from action 7.1 will be used to design a selective breeding programme to produce marteiliosis-resistant cockle strains.

Much information on procedures to restore oyster beds and reefs is available from USA programmes. Information from previous mollusc restoration programmes and from WP6 on larval dispersal and genetic markers to discriminate cockles from different geographic areas will be used to design procedures to restore exhausted cockle beds and to evaluate the success.