Caribbean Reef Fish Guide

An apex predator and keystone species. Critically depleted across the Caribbean due to overfishing and habitat loss. Nassau Grouper are broadcast spawners that aggregate in predictable locations — making them highly vulnerable to both fishing pressure and Lionfish predation on juveniles. CRFF is currently in the active monitoring phase for this species, cross-referencing NOAA stock assessments with CORE diver reports on Lionfish presence to identify candidate release zones.

One of the most commercially important groupers in the Caribbean. Red Hind form predictable winter spawning aggregations at known sites off St. Croix — the same site-fidelity that makes the species economically valuable also makes them acutely vulnerable to fishing pressure and Lionfish competition. CRFF is actively logging CORE diver-reported Lionfish sightings at two known aggregation sites.

A small but ecologically important grouper found on virtually every Caribbean reef. The Coney exists in multiple color phases including red, bicolor, and golden. Despite being less targeted by commercial fishers than larger groupers, Coney juvenile survival is a useful indicator of overall juvenile reef fish health — and a direct measure of Lionfish pressure intensity.

A small, secretive grouper that lives deep within reef structure. The Graysby is an ambush predator that competes directly with Lionfish for juveniles and small crustaceans. CRFF is conducting data-gathering transects to document the degree to which Lionfish presence alters Graysby foraging behavior and reduces competitive fitness.

One of the largest groupers in the Caribbean and a critical apex predator that helps structure reef communities. Severely overfished across its range, it has been functionally extirpated from many Caribbean reefs. CRFF is gathering NOAA and USVI DPNR historical data to map former Black Grouper territory in St. Croix as the first step toward identifying viable recovery zones.

A commercially important and ecologically significant snapper. Yellowtail Snapper are schooling fish that transit between reef, seagrass, and mangrove habitats across their lifecycle. CRFF is cross-referencing NOAA stock assessment data with CORE diver-reported Lionfish sighting data to build a juvenile habitat map for the St. Croix seagrass nursery network.

A major reef predator that aggregates seasonally to spawn at predictable sites off St. Croix. CRFF holds active observation data at two known Mutton Snapper aggregation sites and is cross-referencing this with NOAA seasonal stock assessment windows to determine if aggregation size has changed since 2020.

A wide-ranging snapper that links reef, seagrass, and mangrove habitats across its lifecycle. Juveniles depend heavily on mangrove nurseries — the same shallow, complex environments where Lionfish have established with minimal predator resistance. CRFF is conducting nursery habitat surveys at key mangrove sites in St. Croix to assess juvenile snapper density relative to Lionfish presence.

One of the most common and ecologically important snappers in the Caribbean. Gray Snapper use mangroves as essential juvenile nurseries before migrating to reef habitats as adults. Their abundance across multiple habitat types makes them a high-value sentinel species — measurable declines in Gray Snapper signal reef-wide ecosystem stress that CRFF uses to benchmark monitoring zone health.

Parrotfish are the reef's architects — producing the fine white sand of Caribbean beaches and grazing algae that would otherwise outcompete coral. The Queen Parrotfish is a priority collection candidate for CRFF: healthy specimens have been identified in low-Lionfish-pressure zones. CRFF is currently in the collection assessment phase, evaluating holding capacity and ecological readiness of target release zones.

Named for the red, yellow, and green coloration of its adult supermale phase, the Stoplight Parrotfish is the most common large herbivore on Caribbean reefs. When present, it is a positive indicator of reef health. CRFF is actively monitoring Stoplight Parrotfish density across survey zones as a grazing pressure indicator — a direct input to coral recovery modeling.

The largest parrotfish in the Atlantic and one of the largest reef fish in the Caribbean. The Rainbow Parrotfish is entirely dependent on mangrove nursery habitats as juveniles — making it one of the species most threatened by combined mangrove loss and Lionfish predation. IUCN lists it as Endangered across much of its range. CRFF is in the collection assessment phase, evaluating the condition of remnant mangrove nursery habitats before any collection or release planning can proceed.

A small but ecologically important parrotfish that grazes extensively across both coral and seagrass. The Redband Parrotfish bridges two critical reef-adjacent ecosystems and is among the parrotfishes most heavily affected by Lionfish in the seagrass nursery habitat where juveniles spend their earliest months. CRFF is gathering baseline count data in seagrass monitoring zones.

One of the most abundant and ecologically important wrasses on Caribbean reefs. The Bluehead Wrasse operates critical cleaning stations where it removes parasites from larger fish. Loss of cleaning services cascades through the entire fish community. Juvenile Blueheads are a documented primary prey item of Lionfish — making this species a high-value target for Lionfish impact monitoring.

A colorful and charismatic wrasse that provides critical cleaning services at reef stations. Spanish Hogfish cleaning behavior is disrupted by Lionfish presence, which deters other fish from approaching active stations. CRFF is gathering baseline data on cleaning station activity density as a proxy for Lionfish pressure in survey zones.

The Creole Wrasse forms enormous schools above Caribbean reefs, feeding on zooplankton and transferring energy from the water column into the reef food web. CRFF is gathering data on Creole Wrasse school density and composition across monitoring zones to detect early recruitment gaps before they become visible in adult population counts.

Among the most visually striking species in the Caribbean. The Queen Angelfish is a sponge specialist whose grazing maintains the balance between sponge and coral cover on the reef. CRFF is actively monitoring Queen Angelfish density in St. Croix survey zones, using their presence as an indicator of high-quality coral reef structure.

Bold, territorial, and ecologically important. The Rock Beauty occupies a critical mid-tier role in reef food webs, grazing on tunicates and sponges that would otherwise outcompete coral for substrate. CRFF is cross-referencing CORE diver-reported Lionfish sightings with Rock Beauty territorial density counts as part of the baseline for St. Croix candidate release zones.

Often seen in mated pairs patrolling the reef. French Angelfish are prominent cleaning station operators — removing parasites from larger fish at fixed reef sites. CRFF monitoring data includes French Angelfish cleaning station density as one of seven reef health proxy metrics tracked across St. Croix survey zones.

The Gray Angelfish is a close relative of the French Angelfish, filling a similar ecological role as a sponge grazer and parasite cleaner. While adult Grays are not directly threatened by Lionfish, CRFF data gathering is documenting juvenile survival rates in the shallow reef habitats where young Gray Angelfish first establish territories.

A critical herbivore native to Caribbean and Atlantic reefs — not to be confused with the Indo-Pacific Hippo Tang. The Caribbean Blue Tang grazes algae from coral surfaces, playing an irreplaceable role in preventing algal overgrowth that would smother coral. Juveniles are brilliant yellow, transitioning through a blue-and-yellow phase before reaching adult deep blue coloration. CRFF is in the collection assessment phase, evaluating healthy adult specimens in low-Lionfish-pressure zones for future breeding stock identification.

One of the most common grazers on Caribbean reefs, the Ocean Surgeonfish travels in mixed-species schools that maintain algae-free coral surfaces across the reef. Their grazing is essential for coral recruitment. CRFF uses Ocean Surgeonfish school density as a proxy for grazing pressure sufficiency in candidate release zone assessments.

Named for the sharp spine near the tail, the Doctorfish is a robust Caribbean grazer that schools frequently with Caribbean Blue Tang and Ocean Surgeonfish. As a mixed-species grazing school, these surgeonfishes jointly maintain reef health across multiple zone types. CRFF monitors Doctorfish as part of herbivore density assessments in candidate release zones.

One of the most abundant and visible fish on Caribbean reefs. The Sergeant Major's relatively stable population makes it a high-value ecosystem baseline indicator for CRFF. Their density across monitoring sites is used as a control variable in Lionfish impact assessments — a declining Sergeant Major count signals broader ecosystem stress that CRFF uses to escalate intervention priority.

The Blue Chromis forms glittering schools above Caribbean reef structures, feeding on zooplankton and transferring energy from the water column into the reef food web. CRFF uses Blue Chromis school density as a supplementary reef health indicator in monitoring transects, particularly along reef wall environments where Lionfish also tend to concentrate.

The Queen Triggerfish is a charismatic species once common across Caribbean reefs. It plays a notable role in controlling sea urchin populations, which in the absence of this and other reef predators can balloon and cause destructive overgrazing. CRFF is in the collection assessment phase — healthy specimens have been identified in several St. Croix monitoring zones, and ecological readiness of candidate release sites is being evaluated.

Tiny but ecologically vital. The Royal Gramma provides critical cleaning services and serves as food for larger reef predators. CRFF has identified specific reef caves at Frederiksted Pier and two additional offshore sites as high-density Royal Gramma zones. These sites are currently mapped as planned release zones for future paired-species reef restoration work, pending Lionfish pressure assessment.

Among the most common butterflyfishes in the Caribbean, the Foureye is entirely dependent on live coral — feeding on coral polyps, worms, and small crustaceans. Its presence is a direct indicator of living coral health. CRFF monitors Foureye Butterflyfish density as a coral vitality proxy in all active reef assessment zones.

The Spotfin Butterflyfish lives and feeds exclusively on healthy coral reef structures, making it one of the most sensitive indicators of reef decline. CRFF documents Spotfin density alongside Foureye density in its coral health monitoring protocol — together, their counts function as a standardized index of reef structural integrity.

A fast, schooling predator that hunts cooperatively across reef flats and grass beds. Bar Jack often school with other species and are a visible sign of an active, healthy reef ecosystem. CRFF is gathering data on Bar Jack school size and frequency of reef flat patrols as a proxy for midwater fish community health in St. Croix monitoring zones.

A nocturnal predator that shelters in reef crevices by day and feeds on small fish and invertebrates at night. The Longspine Squirrelfish competes directly with Lionfish in the nocturnal feeding niche. CRFF field teams document Squirrelfish shelter site density as a reef structural complexity indicator in all active monitoring zones.

One of the most visually iconic fish in the Caribbean — the juvenile Spotted Drum has a dramatically elongated dorsal fin rivaling a black-and-white banner. Adults are intensely site-faithful, returning to the same reef cave each day. CRFF field teams track individual adult Spotted Drum at Frederiksted Pier as long-term reef site sentinels — their continued presence at a site confirms that the underlying reef structure has remained intact.