Help Identify Yucatan Mexico Fish

by Colin
(Montreal, Canada)

Part of a recent whale shark tour off the northern coast of the Yucatan Peninsula in Mexico included a snorkeling equipment check in relatively shallow water just offshore.

There was great fish density, some huge angelfish and a large number of the fish shown in the photograph. They were about two feet long, had two barbels and swam in a very shark like manner. The guide could only identify them as Caribbean Catfish. I've tried to find them in the Humann and Deloach Caribbean Fish ID Book with no success. Any ideas?

Thanks.