European sea urchin Paracentrotus lividus as a part of IMTA system.  

*Muki Shpigel, David Ben-Ezra, Vladimir Odnietzov, Lilach Shauli.  
 
1 National Center for Mariculture, Israel Oceanographic and Limnological Research, P.O.B. 1212, Eilat 88112, Israel
 

The sea urchin Paracentrotus lividus was introduced as a candidate species for commercial development in a fish, seaweed and sea urchin Integrated Multi-Trophic (IMTA) system in Eilat (Red Sea), Israel. While the fish represented the main product, effluents from fish culture supported the growth of the macroalgae Ulva lactuca and Gracilaria conferta. Both seaweeds were used as a biofilter to remove dissolved nutrients from the water and as forage for the sea urchins.

Sea urchin performances in terms of survival, growth, food conversion ratio (FCR), protein and energy use, gonad development and color were evaluated. Growth from spawning to commercial size (45 mm) on the seaweed diet took approximately 36 months, FCR on a wet weight basis ranged between 5-7, and survival rates from settlement were 70-80%. Three months before harvest, prepared diets were administered to accelerate growth.

*Muki Shpigel: shpigelm@agri.huji.ac.il