Welcome! The Arizona Rivulin Keepers (ARK) is a not-for-profit, educational association dedicated to promoting the public knowledge, care, and breeding of a group of fishes collectively known as killifishes. Meetings are free and the public is invited. Club Information Membership How to Join - PDF file Background Information Current Information Past Programs Photos Our Sponsors Corporate Sponsors Local Sponsors Special interest Articles Written by ARK Members ARK Newsletters - Members Only Special Killifish KMI 4 : Ready Reference Guide to Names Scheel Letters Joergen Scheel's killifish letters from the early 60's Links Links to Other Sites of Interest