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Analysis of the metabolic needs of Mytilus spp. that may cause gaping



The phenomenon of gaping observed in cultivated mussels in Quebec, particularly in the Gaspé region, is a major obstacle to the development of the mussel aquaculture industry. Consumers are very reluctant to buy open mussels. Mussels from Prince Edward Island, Quebec's main competition in this market, are reported to have a significantly lower incidence of gaping. It is therefore critical for the Quebec mussel aquaculture industry to gain an understanding of this phenomenon in order to be able to address it. The purpose of this project is to determine whether the propensity of mussels for gaping is voluntary and caused by their physiological requirements when exposed to air, or whether it is caused by a decrease in tone of the adductor muscle, which controls valve movement. The appearance of gaping so soon after harvesting suggests that priority should be given to verifying this hypothesis in order to understand this phenomenon. It should also be pointed out that debyssing is known to cause severe stress in mussels, which may result in an increased propensity for gaping. However, in order not to complicate the experimental protocol, this second hypothesis could be verified through a separate study that would be complementary to this project. The general objective of the current study is to verify whether the propensity for gaping in mussels exposed to air results from a lack of sufficient oxygen to meet their metabolic needs or from a lack of muscle tone.

Specific objectives:

  1. Observe whether temperature influences the intensity of metabolic activity in mussels and their propensity for gaping.
  2. Observe whether icing the mussels with large quantities of ice immediately after they are removed from the water helps reduce their metabolic activity, increase their stress tolerance and decrease their propensity for gaping.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)


2007 - 2010


Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Marcel Fréchette

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