The Dr. Rogelio Rosas Valdez performed a postdoctoral stay in the lab from the 2010 to 2012. He studied the taxonomy and systematic of the genus Floridosentis a group of acanthocephalans parasites of mullet fishes from Gulf of Mexico and the Pacific coasts. The Dr. Rosas Valdez participated in several field trips collecting diverse groups of helminths associates to freshwater fishes and aquatic birds. The Dr. Rosas-Valez published several papers during his stay in the lab. He helped and advise the graduate students with the morphological and molecular techniques. The Dr. Rosas Valdez is an expert in the taxonomy of the tapeworms and his favorite group are the freshwater and marine fishes as his Ph.D mentor the Professor Gerardo Pérez Ponce de León. Currently the Dr. Rosas Valdez is an independent researcher very successful from the Universidad Autónoma de Zacatecas.