Effects of Dietary Protein and Carbohydrate Levels on Gonad Index, Composition, and Color in the Purple Sea Urchin Strongylocentrotus purpuratus

• Published in: North American journal of aquaculture 2018-04, Vol.80 (2), p.193-205
• Main Authors: Cuesta‐Gomez, Diana Maria, Sánchez‐Saavedra, M. del Pilar
• Format: Article
• Language: English
• ISSN: 1522-2055; 1548-8454
• DOI: 10.1002/naaq.10022

Understanding the nutritional requirements of the purple sea urchin Strongylocentrotus purpuratus is essential for producing suitable formulated diets and promoting its aquaculture in Mexico. Protein and carbohydrates are required components for gonad growth in sea urchins, yet their levels and effects on gonad composition and color have not been determined for this species. The effects of dietary protein and carbohydrates on gonad index, consumption, proximate content, and color were investigated in S. purpuratus in a 12‐week experiment, from April to June 2015. Sea urchins were collected from Arbolitos Bay in Ensenada, Baja California, Mexico, and fed diets that contained three protein levels (300, 230, and 170 g/kg) and two carbohydrate levels (420 and 500 g/kg). All diets significantly increased gonad index, but individuals that were fed a diet with 300 g/kg of protein and 500 g/kg of carbohydrate had the highest gonad index. Dietary protein had a significant effect on lipid storage, whereas protein and nitrogen‐free extract storage had no significant relationship with dietary protein or carbohydrate. Differences between gonad color and the standard color cards indicated that S. purpuratus gonads tended to be closer to an orange‐yellow color. This study indicates that S. purpuratus will have increased gonad index values at all protein and carbohydrate quantities that were tested in this study. However, gonad coloration is more suitable with a diet containing 230 g/kg of protein and 500 g/kg of carbohydrates.