Physiological and genetic basis of growth in soft-shell clam, Mya arenaria

Description

Knowledge of the physiological and genetic characteristics governing the growth performance of individuals is the basis for developing culture management methods that eliminate individuals with poor growth potential. This goal can be achieved by using selective methods (Deming & Russell 1999, LeBlanc et al. 2005) or developing hatchery strains (Samain et al. 1992, Grecian et al. 2000). However, it is important to ensure that these techniques do not weaken the populations by reducing the potential for resistance to environmental stresses and disease. Aquaculture techniques appear to be a primary factor in the low disease resistance of quahogs (Mercenaria mercenaria), which has resulted in the decimation of beds on the east coast of the United States. This risk can be significantly reduced by acquiring sufficient knowledge of genetic and physiological mechanisms. The main objective of this project is to determine the physiological and genetic characteristics that differentiate soft-shell clams (Mya arenaria) on the basis of their growth in order to assess the prospects for developing a culture management method that maintains high growth rates without weakening the farmed stocks.

Attaining these objectives will require:

1. Developing a large-scale individual physiological measurement technique for endobenthic organisms;
2. Obtaining clams characterized by different growth levels;
3. Characterizing the physiological parameters (filtration, assimilation, maximum and basal metabolism) of no-growth, low-growth and high-growth individuals;
4. Characterizing the genetic basis (isoenzymes and microsatellites) of no-growth, low-growth and high-growth individuals;
5. Assessing the impact of the elimination of low-growth individuals on the genetic diversity of farmed populations and on the metabolic budget (indicator of the amount of energy available to resist stresses and disease).

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2006 - 2007

Ecoregion(s)

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

Principal Investigator(s)

Jean-Marie Sévigny
Email: Jean-Marie.Sevigny@dfo-mpo.gc.ca