Investigation of Early Development and Importance of Sediment Choice in the Hatchery Production of Razor Clams, Ensis Directus

Ensis directus, commonly known as the razor clam, is a bivalve species that lives in temperate sub-polar regions of the Atlantic Ocean. It is an infaunal species found in shallow, subtidal, sedimentary habitats. A recent increase in the market value for razor clams has resulted in heightened interest in the culture of this species. The experimental hatchery at the University of Maine’s Darling Marine Center began work in 2012 to develop improved hatchery and grow-out techniques for this species. For my thesis, razor clam embryos from both spontaneous and controlled spawns were observed via video and still imagery to document the timing of early development. I obtained additional footage and images of clams during the larval phase through metamorphosis to determine morphological features that are associated with the onset of settlement in this species. I conducted experiments investigating the sediment preference of razor clam larvae and tested methods for improving the settlement rate and early post-settlement survival. Lastly, I determined the burrowing rates of juvenile razor clams to help identify appropriate sediments for nursery phase culture. The results of my research will aid in the development of razor clam aquaculture techniques that can be used by Maine’s shellfish culture industry