Andrés Mansilla1,2,3, Marcela Ávila3,4, Francisco Bahamonde1,2,5, Juan Pablo Rodríguez1,2,6, Fabio Méndez1,2,6, Alí Rivero7, Zambra López1,3, Ricardo Riquelme4, Gesica Aroca2,4, María Inés Piel4, Edison Serrano4.
1Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Punta Arenas, Chile.
2Cape Horn International Center (CHIC), Universidad de Magallanes, Punta Arenas, Chile.
3Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE).
4Instituto de Ciencia y Tecnología, Universidad Arturo Prat, Puerto Montt, Chile.
5Programa de Magíster en Ciencias mención Manejo y Conservación de Recursos Naturales en Ambientes Subantárticos, Universidad de Magallanes, Punta Arenas, Chile.
6Programa de Doctorado en Ciencias Antárticas y Subantárticas, Universidad de Magallanes, Punta Arenas, Chile.
7Centro de Cultivos Marinos, Bahía Laredo, Universidad de Magallanes, Punta Arenas Chile.
In Chile, diets based on macroalgae to feed sea urchins started in the 1990s. Here, the researches were focused on the effect of growth and gonadal quality of adult individuals. In this study, we evaluated the effect of extruded foods, where the macroalgae Macrocystis pyrifera, Sarcothalia crispata, Ulva spp. and Pyropia spp. were incorporated, for improving growth and survival rates of juvenile of L. albus destined for restocking. Bioassays were realized at the same time in Los Lagos and Magellan regions between the fall and winter of 2021, with a duration of 90 days. In Magellan region, the temperature was colder than Los Lagos region, the first ranged between 3 and 6°C, and the second between 10 and 12°C. A total of 375 juvenile sea urchins (from 5 to 15 mm) were used to record food consumption, growth rates and survival. Four diets containing macroalgae meal and various protein concentrations and energy levels were used, plus a control diet with live macroalgae. Significant differences were observed in the average percentage of food consumption in the different diets (p<0.01). Growth rates also showed significant differences according to the diet (p<0.001). Food consumption was higher in Los Lagos region, probably associated with higher temperatures. Conversely, in Magellan region, growth rates higher than in the control treatment were recorded. Survival ranged between 70 and 85%. Results are consistent with the viability of using inert diets for the development of juvenile L. albus. This lays the foundation for future sustainable development of the resource.