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 2 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/Deloach Caribbean Fish ID book with no success. Any ideas?

Thanks.