Understanding Interior Shell Pigmentation in the Northern Quahog to Inform Site-Appropriate Brood Stocks for Aquaculture

Commodities

• Animals: shellfish

Practices

• Animal Production: aquaculture, livestock breeding

The purple shell color found in the interior of the northern hard clam, or quahog, Mercenaria mercenaria, occurs in a narrow latitudinal range in the northeastern United States. Indiginous people have used both the white and purple parts of shells of hard clams to make traditional cylindrical beads, or wampum, for more than one thousand years. Scant research indicates potential protective properties of the purple shell color, and yet the proposed study will be the first to address the function (hardness) and heritability of purple shell color in this species. The goal of this research is to increase our understanding of the purple shell color found in some hard clams so that scientifically informed decisions can be applied to selective breeding for private/commercial, public and restoration aquaculture activities. The findings from this study will support the essential cultural and economic needs of Indigenous peoples as well as increased aquaculture production and profitability. 

This will be the first study to address the function and heritability of purple shell color in this species. The objectives of this study are to 1) determine if the purple shell is harder (and therefore more resistant to crushing predators) than non-pigmented shell; 2) if selection for the purple shell color is in fact possible; and 3) if purple shell color increases survival on aquaculture sites. The goal of this research is to increase our understanding of the purple shell color found in some northern hard clams so that scientifically informed decisions can be applied to management, restoration, and selective breeding for aquaculture. The findings will also support the essential cultural and economic needs of Indigenous peoples such as the Wampanoag Tribe of Aquinnah, MA. Subsequent work has the potential to create an enticing marketing opportunity for the quahog industry by enabling the reliable production of a colorful and aesthetically exciting food product, in addition to increased survival of hard clam juveniles.