We are encouraging all REEF surveyors in the Tropical Western Atlantic region to be on the lookout for a new non-native fish! Researchers from the University of Veracruz have documented a new non-native species in the southwestern Gulf of Mexico with the potential to spread throughout the region. Sightings of the Regal Demoiselle (Neopomacentrus cyanamos) have recently come from the nearshore reef systems south of Veracruz, Mexico. The species is native to a broad region of the Indo-Pacific and Red Sea. The damselfish was documented at depths from 2-21 meters, though it was more common on deeper reefs. Similar in appearance to the native Brown Chromis, the Regal Damsel can reach sizes of up to 9 cm (3.5 inches) in length and is distinguished by a yellow or white spot at the rear base of the dorsal fin, a dark spot behind the gill, and yellow rear margins of the tail, dorsal and anal fins. In contrast, the native Brown Chromis is identified by dark margins on the tail and a dark spot at the base of the pectoral fin. Observations from Dr. Ross Robertson indicate the Regal Demoiselle can be a bit more cryptic than the native Chromis, tending to hide under ledges and in crevices between corals, rather than swimming in the open. Experts in Mexico believe that this damsel has the potential to disrupt natural systems around Caribbean reefs, as they have witnessed displacement of the native Brown Chromis on heavily-invaded sites.
If you see this fish while doing a REEF survey, be sure to report it on your form in the unlisted fish section. Please also report detailed information on the sighting to REEF through the invasive species reporting page.