The pain of a lionfish sting delivered to a human can last for days and cause suffering, sweating and respiratory depression (Grant, 1999). Experimental evidence suggests that commercial stonefish antivenom does have some detoxifying affect on lionfish venom (Shiomi et al, 1989).
Perception Channels: tactile ; chemical
Pterois miles is not currently listed as threatened or endangered. However, the increase in pollution in coral reefs is expected to kill many of the fish and crustaceans, which lionfish depend on. If lionfish are unable to adjust to these changes by selecting alternate food sources, it is expected that their populations will also decrease (Fishelson, 1997).
US Federal List: no special status
CITES: no special status
None
Pterois miles is a popular aquarium fish. They are stripped from the wild to make money for the popular pet industry.
Pterois miles is one of the top levels of the food web in many coral reef environments. They are known to feed mostly on crustaceans (as well as other invertebrates) and small fishes, which include juveniles of their own species. Pterois miles consumes an average of 8.2 times its body weight per year (USGS, 1999). As juveniles they consume 5.5-13.5 g per day and 14.6 g a day as adults.
Sunset is an optimal time for Pterois miles to begin feeding because this is when activity in the coral reef is highest. At sunset, all of the day fish and invertebrates make their way to a resting spot for the night and all of the night fish come out to begin feeding. With all of these creatures around, the lionfish need not invest much energy to find a meal. They simply glide upwards along the rock and coral sneaking up on unexpecting prey from below. While moving slowly towards a small fish, Pterois miles uses its open pectoral rays to shield the motion of its caudal fin. This shielding along with the cryptic coloration of the predator prevents the prey from becoming alarmed. Although we find the striped colorful pattern of the lionfish obvious and easy to see in an aquarium setting, in the coral reef this colorful pattern allows the fish to blend into the background of coral branches, feather-stars, and spiny sea urchins.
The lionfish attacks with one swift gulping motion that sucks the prey into its mouth. This attack is so quick and smooth that if the victim is among a group of fish, the other fish in the group may not even notice what happened. The lionfish can continue to hunt the other unaware members of the group.
Pterois miles has also been known to hunt for fish in the open water near the surface with a different technique. Here they wait 20-30 cm below the surface and watch for small schools of fish leaping out of the water in an attempt to escape another predator. When they plunge back into the water the lionfish is waiting just below them ready to attack (Fishelson, 1975)
In addition to fish, Pterois miles feed on invertebrates such as amphipods, isopods, and other crustaceans. The lionfish glides along the substrate (rocks or sand) and vibrates the rays on its fins in order the rustle the food out of hiding.
In general, the lionfish is stationary and feeds on as many fish as it can when fish are plentiful and then it fasts when food is scarce (Fishelson, 1997). When a lot of food is available for feeding, Pterois miles becomes satiated or full and may not eat for at least 24 hours (Fishelson, 1997).
Lionfish invest most of their energy in growing to a large body size early in life. This tactic allows them to grow big at a fairly young age so that they are more likely to avoid attack by predators and increase their chances of mating successfully (Stearns and Crandall, 1984).
If a male lionfish meets another male while hunting, the more aggressive male will turn darker in color and point its poisonous, spiny dorsal fins at the other individual who usually folds down its pectoral fins and swims away.
Native Range:
Indo-Pacific: western Australia and Malaysia to the Marquesas Islands and Oeno; north to southern Japan and southern Korea; south to Lord Howe, Kermadec, and Austral Island ( map of the indigenous occurrances of Pterois miles).
Nonnative Range:
Pterois miles was introduced to Key Biscayne, Florida when a beachside aquarium broke during Hurricane Andrew in 1992. Furthermore, the intentional release of aquarium pets has contributed to the Florida population (USGS, 1999). It is not know what the biological implications of this introduction might be ( map showing the nonindigenous occurrences of Pterois miles).
Lionfish are primarily reef associated but also found in warm, marine water of the tropics (Grant, 1999). They tend to glide along the rocks and coral during the night and hide out in caves and crevices during the day.
Aquatic Biomes: reef ; coastal
Average lifespan
Status: wild: 10.0 years.
The lionfish has a beautifully banded head and body with reddish or golden brown bands stretching across a yellow background. The dorsal and anal fins possess dark rows of spots on a clear background.
Pterois miles are differentiated from other scorpionfishes by having 13 rather than 12 poisonous dorsal spines and 14 long, feather-like pectoral rays. The anal fin has 3 spines and 6-7 rays.
Pterois miles can grow to a maximum length of 38 cm.
Some other noteworthy characteristics of Pterois miles are the bony ridge across the cheek and the flaps that partially cover both the eyes and nose. They also possess a "tentacle" above both eyes.
Other Physical Features: bilateral symmetry
Only while courting will Pterois miles aggregate with other individuals. In this special case, one male will aggregate with several females to form groups of 3-8 fish.
When lionfish are ready to reproduce, the physical differences between the sexes become more obvious. Males turn darker and are more uniformly colored (their stripes are not as apparent). Females with ripening eggs become paler. Their belly, pharyngeal region, and mouth become silvery white. Such females are easy for the males to spot in the darkness.
Courtship begins just before dark and is always initiated by the males. After the male searches out a female, he rests next to her on the substrate and looks toward the water surface while propping himself up on his ventral fins. He then proceeds to circle the female. After circling several times, the male then ascends to the water surface with the female following behind. While ascending the female will tremble her pectoral fins. The couple may descend and ascend several times before spawning. On the final ascent the couple will swim around just under the surface of the water. The female will then release her spawn. These spawn are comprised of two hollow mucus tubes that float just below the surface upon release. After approximately 15 minutes, these tubes fill up with seawater and become oval balls 2 to 5 cm in diameter. Within these mucosal balls lie 1-2 layers of individual eggs. The number of eggs per ball varies from 2,000 to 15,000. As the female spawn are released, the male releases his sperm, which penetrate the mucosal balls and fertilize the eggs inside.
Twelve hours after fertilization the embryo begins to form. Only 18 hours after fertilization, the head and eyes become moderately developed. Eventually, invading microbes deteriorate the mucus walls and 36 hours after fertilization, the larvae hatch. Four days after conception, the larvae are already good swimmers and are able to begin feeding on small ciliates (Fishelson, 1975).
