John Scarpa, Ph.D. and Leslie N. Sturmer (University of Florida)
The hard clam aquaculture industry of Florida is a dramatic success story. However, production of cultured hard clams (quahogs) in Florida is primarily increasing through expansion of cultivation area. During the past few years, the need for a hardier clam strain has become evident as clam culturists in Florida report below average survivals or total losses. Strain development through basic breeding takes many years and large financial and physical resources to accomplish. However, a quicker method to capitalize on local genetics is through other breeding techniques, such as hybridization.
Studies in the 1970s examined the hybrids of northern (Mercenaria mercenaria) and southern (M. campechiensis) hard clam species, with the objective of producing faster growing clams for aquaculture. The hybrid had as good or better growth as the faster growing southern hard clam, with the shelf life as good as the northern hard clam parent. Unfortunately, the merit of hybrids for improved survival was not examined. There is a dearth of information regarding the commercial value of hybrid clams for increased stress resistance and survival, rather than increased growth, in Florida and elsewhere. Therefore, a rigorous examination on the production and utilization of clam hybridization for increasing survival and overall clam production in Florida waters is warranted.