Belize Reef Invader: Lionfish

Pterois volitans


The Lionfish is an unwelcome predator to any aquatic reef system except it’s home in the Indian and Pacific Ocean reefs. According to recent literature, the Lionfish invasion started accidentally in the Florida panhandle when Hurricane Andrew in 1992 hit the Florida coast. During this storm, it is believed that a small population of Lionfish were exposed in the storm surge and escaped from their pet store tanks and found a new happy home in the warm waters of the Gulf of Mexico (NPR). The rest is documented by marine biologists that study reef systems from the Atlantic coast of Carolina’s, Florida Keys, Gulf of Mexico, and Central America (NOAA). These fish have been populating reefs voraciously and causing negative impacts on the local reef ecosystem.

CAUTION! The Lionfish spines of this species are venomous and can cause extreme pain if one comes in contact. Resulting in extreme pain, swelling and respiratory distress (NOAA, 2011)

Taxonomic Classification

Kingdom Animalia

Phylum Chordata

Class Actinopterygii

Order Scorpaeniformes

Family Scopaenidae

Genus Pterois

Home Range: Indian Ocean and Western Pacific Ocean reefs. Depths 1m-50m.

Lifespan: 5-10 years.

Size: Typically 15-30cm in length. Largest recorded size was 1.1 kg and 43cm.

Habitat: Near coral reef structure. Not an open water fish.

Behavior: Highly cryptic, feeding at night. Daytime spent in holes and caverns in hiding.

Reproduction: Larval stage lasts from 20-40 days. 2-3 days post hatch individuals can consume zooplankton.



This species of Lionfish is native to Western Pacific and the Indian Ocean. Including southern Japan to eastern Australia and all Indonesian Islands. Typically in waters < 30m deep. However, off the coast of Carolina, a sea-floor voyage in 2002 caught two Lionfish at 182ft deep ( NOAA,2002). In its native habitat, the Lionfish lives within the reef structure. On hard surfaces, sea grass, or artificial reefs. It seeks holes and ledges to spend the daylight hours while coming out to feed at night. Being a native to the Indo-Pacific Ocean allows the organism to make a smooth transition into the marine environment along the south-eastern US waters and the Gulf of Mexico. This is because it is similar in reef structure, salinity, and most importantly temperature (Jud).

In their unnatural habitat, Lionfish prey on any fish that it can physically consume. Showing very little discretion when consuming fish species. This is predicted to have disrupted affects on both coral reef diversity and function (Mumby et. al). Although physical research on this disruption is not clearly researched yet, it is a unanimous assumption between researchers that Lionfish invasion has detrimental effects on coral reef ecosystems.


Lionfish are nocturnal fish and prefer to feed and be active during night hours rather than daylight. With this assumption in mind, they are not strictly nocturnal fish. Many have been seen active in the daylight on occasion. When they are active, their movements are slow and methodic. This slow movement causes the fish to rely on its excellent camouflage to attack prey. During consumption, the Lionfish will engulf the prey in one rapid motion leaving little escape for its prey. They are active predators and have been documented to use their huge pectoral fins to slowly corner and consume prey (NOAA, 2011).


Lionfish is a predator on small reef fish, shrimps and crabs. It is known for extreme aggression when pursuing prey and is considered a flexible predator. Meaning it will consume a wide variety of organisms with no real discretion. This is part of the reason why on the Atlantic coastal reefs, this fish has become one of the top reef predators within a short amount of time. Consuming approximately 50 species of fish, some ecologically and economically important (NOAA, 2011).

Natural Predation and Future Outlook

There are very few natural predators of a grown Lionfish. When Lionfish are in their larval stage, the larvae are consumed naturally, with no discretion by planktonic predators. However, once a Lionfish has reached adulthood, the poisonous nature of its fins and its aggression make the Lionfish an unwanted food source for many marine fish. A study done by Harbone Mumby in 2011 considered the grouper as a natural predator and therefore a possible bio-control of this invasive Lionfish (Mumby et al).  The study cited known natural predators to Lionfish as; grouper (nassau and tiger), humped scorpionfish, and some accounts of triggerfish antagonizing the Lionfish.

The overall effect of an increased Lionfish population within its unnatural range has yet to be fully determined. All current studies predict a grim outlook if the Lionfish continues to grow in population within its invasive range. By continuing research, marine biologists will be able to document the effect of the Lionfish and predictions can be either altered or confirmed. As of now, the current sightings of Lionfish in the Belize Reef System is a negative sign and I hope eradication efforts will continue in order to stop the growth of this invasive species.

Personal Interest

I enjoy researching and learning about how invasive species can alter natural ecosystem processes. Being an Environmental Science student, I have interest in how humans affect their surroundings. Whether it’s good or bad, many things will change. This is just part of the natural succession of living organisms. Seeing how nature will react is the interesting element.


Dornfield, Ann. Spreading lionfish invasion threatens Bahamas. National Public Radio. August 9, 2009. Web accessed May 29, 2012.

Jud Z, Layman C. Site fidelity and movement patterns of invasive lionfish, Pterois spp., in a Florida estuary. Journal Of Experimental Marine Biology & Ecology . March 15, 2012;414-415:69-74. Academic Search Complete,
Ipswich, MA. Accessed May 31, 2012.

Mumby P, Harborne A, Brumbaugh D. Grouper as a Natural Biocontrol of Invasive Lionfish. Plos ONE . June 2011;6(6):1-4. Available from: Academic Search Complete, Ipswich, MA. Accessed May 29, 2012.

NOAA. National Oceanic and Atmospheric Administration.  Lionfish biology fact sheet.  May 31, 2011. Web accessed May 29, 2012.

NOAA. National Oceanic and Atmospheric Administration. Lionfish discovery story. March 25, 2008. Web accessed May 29, 2012.