Natural Marine World Tidbits

Spotlight parrotfish by Tom Byrnes

Stoplight parrotfish (Sparisoma viride) at Salt Pier.

The spotlight parrotfish is aptly named because this species, Sparisoma viride, has a red and green color phase

In fact, it was thought to be a distinct species for a period.

Adding to the taxonomic confusion is that most are born as red females, with some primary males, which are also red. Primary males remain male; however, terminal or ‘super males’ come from the female stock when more breeding males are needed, and these guys are bright green.

A prevalent fish species on Cayman’s reefs, they can be found in the waters from Florida to Brazil and may grow to two feet in length.

Although seen munching away on hard corals, they are primarily herbivores and are after the symbiotic ‘algae’ living in the coral tissue. Parrotfish are so named because their teeth are fused, forming a powerful ‘beak’, which enables them to bite into coral skeletons.

Grinding of their pharyngeal teeth results, ultimately, in the excretion of white coral sand – as much as one tonne per acre of reef each year.

Tom Byrnes is the owner/operator of Cayman Marine Lab. He acquired his Coast Guard Captain’s Licence when he was a teenager and worked as a commercial fisherman in his youth. He got his first diving certificate in 1974 with the YMCA. He has worked in the local dive industry for more than 35 years and has a PhD in marine biology.

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