Inverness Research studied the American Museum of Natural History (AMNH) Seminars on Science program for eight years, from its inception in 1998 to 2006. This paper presents teacher survey ratings for "The Diversity of Fishes", along with profiles of two teachers who took the course. Course takers report on the annual follow-up surveys that "The Diversity of Fishes" has benefited them personally and professionally, and that their students also profit. Compared to other AMNH online courses, its bank of resources was rated especially high, and course takers often recommend this course to colleagues. Key findings based on the responses of the 52 learners from 14 states who have completed follow-up surveys about the quality and value of the course are presented. The majority of survey takers (75%) are K-12 teachers, but informal science educators and preservice teachers have also provided feedback about how the courses have benefited them personally and as educators. (Contains 3 footnotes.)