Dr. Elizabeth Cruz and Dr. Denis Ricque are professors of the Faculty of Biological Science at the Autonomous University of Nuevo Leon (UANL), in Monterrey, the industrial capital of northeast Mexico, located 200km south of the Texas border. They spent the 2011-2012 academic year on sabbatical leave at the Hagerman Fish Culture Experiment Station (HFCES) of ARI. Both are experts in shrimp nutrition and feeds. During their stay in Hagerman, they expanded their research to include evaluating the nutritional value of seaweed meal as a supplement to trout feeds.
Since 2000, one of their research topics has been evaluation of various seaweeds as additives in shrimp feeds. The best results have been obtained with the green macroalgae Ulva clathrata. This alga is produced by aquaculture on a pilot scale in Baja California, México, and has been fed to shrimp fresh (co-cultured with white shrimp) or dried (as dietary supplement included at 3 to 5%). Co-culturing shrimp with Ulva results in increased growth and lower feed consumption, and improved final product quality (body pigmentation) and omega-3 fatty acid composition. Adding dried Ulva meal to shrimp feeds improves pellet quality, feed digestibility, and the immune response of shrimp.