Olga asked for a definition of category. What happens when Corydoras species get sucked into the intake of one of them damn canister filters! 8-) Michael -- Michael Serpa * Bay Island Orchids 2311 Pacific Avenue * Alameda, CA 94501 Tel: (510) 521-8245 * Fax: (510) 865-1787 http://www.bayislandorchids.com