Oyster ( <i>Crassostrea virginica</i> ) aquaculture in Texas: A comparison of the effects of density and gear type upon growth, shell shape, condition index and survival

Abstract Commercial oyster farming is a new industry in Texas. Because of this, few guidelines regarding management practices for producers have been established. The purpose of this study was to evaluate the effect of different gear types and stocking densities on various oyster production indices. A project site in Tres Palacios Bay, Texas was outfitted with two farm production systems, floating cages and adjustable longline baskets. Production units were stocked with ~32 mm seed oysters at three densities per system: 150, 200, and 250 per cage and 65, 70, and 90 per basket. Oysters were cultured for a period of 7 months and sampled monthly to determine survival and provide biometric indices of growth (e.g., shell length, shell height, shell width, total wet weight), condition index, and shell shape (e.g., fan ratio, cup ratio). Results for floating cages and adjustable longline baskets indicated high survival rates (98%–99%) with no significant differences ( p ≥ 0.05) associated with stocking density, despite periods of extreme low temperature and salinity. Floating cages and baskets stocked at the highest stocking density showed significantly ( p &lt; 0.05) greater shell length, height, width, and wet weight gain. Cup ratio and condition index were significantly ( p &lt; 0.05) higher for both gear types stocked at the lowest stocking density. There was no significant difference ( p ≥ 0.05) in fan ratio for oysters cultured using different gear types or at different densities. This study demonstrated that husbandry practices, as in other geographical locations, can have substantial impacts on production yields and could be used to accommodate consumer preferences in the new Texas oyster farming industry.