It is often suggested that aquarists offer tangs the occasional piece of meaty food, despite the fact that they are commonly considered to be herbivorous. I always used to wonder at this advice, thinking to myself that I had seen countless numbers of tangs in the wild, yet they were always, and solely, grazing on algal and other plant-based matter. Perhaps it was to help them deal with the fact that many aquarists cannot supply plant-based material on a constant basis: trust me, in the wild, tangs are grazing every minute of the day! Then I came across some amazing behavior.
There had been a significant plankton bloom, the dive guide told me, following some rough weather which had stirred up nutrients, and this, he continued, had led to an awful lot of jellies. Now, I’m not sure how long this predator/prey cycle takes, but I smiled and thanked him for the heads-up, and we started exploring some shallow cave systems. We were in a shallow bay on the Red Sea coast and for whatever reason, the jellies were in abundance and so were the Sailfin Tangs. In fact I’ve never seen so many, including in shoals in the caves. What I’d never seen before though was just how they relished chomping on the jellies, with small groups of them leaving the reef to venture into open water to eat what appeared to be the dead and dying. It was fascinating to watch, and I guess, this is why occasional meaty foods are recommended?