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As from January 2010 The Israeli Journal of Aquaculture-Bamidgeh (IJA) will be published exclusively as an on-line Open Access (OA) quarterly accessible by all AquacultureHub (http://www.aquaculturehub.org) members and registered individuals and institutions. Please visit our website (http://siamb.org.il) for free registration form, further information and instructions. This transformation from a subscription printed version to an on-line OA journal, aims at supporting the concept that scientific peer-reviewed publications should be made available to all, including those with limited resources. The OA IJA does not enforce author or subscription fees and will endeavor to obtain alternative sources of income to support this policy for as long as possible.

Aquaculture methods for queen conch Strombus gigas have been established for several decades. However, there is a need to improve husbandry techniques for the grow out of juveniles. The purpose of this study was to determine the growth and survival of juvenile queen conchs fed artificial diets with increasing levels of a red alga Agardhiella sp. Agardhiella, soy protein isolate, and fish oil were increased at the expense of catfish feed, wheat flour, or both to keep the diets isonitrogenous (38% crude protein [CP]) with increasing protein to energy ratios (83–96 mg CP/kcal). Yttrium was also incorporated as an inert marker for determining the digestibility of dietary nutrients. Juvenile queen conchs were stocked at 75/m2 for a total of 16 conchs per replicate (three replicates) and were fed 125 mg of diet per conch each day for 6 months. Dietary crude protein ranged from 31% to 38%. The dietary lipid, moisture, energy, ash, fiber, carbohydrate, and yttrium in each diet were also determined. Juvenile conchs were measured (shell length and wet weight) every 6 weeks. At the end of the experiment, feces were collected to determine protein, energy, and dry matter digestibility. Results indicated the highest growth rates (0.10 mm/d and 0.11 mm/d) and survival were for conchs that were fed diets containing a soy protein isolate protein substitution of 15% or less. This study highlights the importance of the protein source in the artificial diets of juvenile queen conchs.Received December 14, 2009; accepted June 26, 2010