The Effect of Diet on Weight Gain, Shell Hardness, and Flavor of New-Shell American Lobster, Homarus americanus

Abstract

Harvested newly-shed American lobsters, Homants americanus, placed in pounds for long-term storage are prone to damage resulting from high-density confinement. It is beneficial for the new shell to harden as soon as possible after shedding. Artificial diets offer the potential for adding supplements to increase weight, muscle gain, and shell hardening. In this study, lobsters were fed 5 different diets: herring, fish racks, and prepared diets with three levels of vitamin D for a period of 38 days. After the feeding trial, lobsters were reweighed, and samples of the carapace and claw shell were removed and subjected to a compressive force/deformation test to measure shell strength. Results indicate a significant (P< 0.05) difference in weight gain, with the highest level of vitamin D actually inhibiting gain. Subsamples tested for compressive force yielded a positive correlation between the carapace measurement and feed type. Flavor tests on subsamples showed significant differences between all treatments; herring was the best, followed by pelleted feed and then fish racks. No off-flavors were detected in lobsters fed any of the three diet types.