Enhancing Hediste diversicolor aquaculture production: Density and feeding rate as key variables for intensive production management

This study analyzes the effect of density on growth and feeding rate in Hediste diversicolor . In a first trial, specimens ranging in size from 10 to 500 mg were fed for 15 days at apparent satiety at eight stocking densities ranging from 500 to 16,000 individuals m −2 . In a second trial, the effect of four manageable density levels ranging from 355 to 2471 ind m −2 and three temperatures (14°C, 18°C and 22°C) on the feeding rate was studied, considering the same range of individual sizes. Using multiple regression analysis, equations were obtained to estimate growth, feed intake, and feed efficiency as a function of the variables studied. In addition, a third trial was conducted to investigate the spatial size distribution in culture tanks randomly seeded with juveniles at high densities. Density and body weight were inversely related to growth, feed intake, and feed efficiency, and temperature was directly related to feed intake but inversely to feed efficiency. Mean individual weight and biomass tend to be higher in the central area of the tanks, with a higher density of small individuals toward the periphery. Simulations performed with the equations obtained under different scenarios of real production show that managing density allows significant performance enhancement.