Species of the week

Meet the Pterois miles, a species of venomous marine fish that can kill even humans

Scientific name: Pterois miles

Common name: Devil firefish /Lionfish

Class: Actinopterygii

Order: Scorpaeniformes

Family: Scorpaenidae

Genus: Pterois

Longevity: can survive up to 10 years in its natural environment,with favorable ecological conditions.

Population: increasing

Diet: Mainly feedsupon benthic fish, but sometimes can eat crustaceans.

Length: can grow up to 35 cm


Pterois miles is a venomous marine fish species, native from the Indian Ocean, characterized by its spines with apocrine glands that produce venom in its body, capable to cause human death. These spines are enveloped in an integumental sheath or skin and contain two glandular epithelial furrows which comprise the tissue that produce venom. The glandular tissue of the spine extends about 3/4 of the distance from the base of the spine to the tip.

These venomous spines are used for their protection against predators and for hunting.

P.miles presents a reddish or grey coloration, with numerous dark and thin bars on the body and head. It has two tentacles above each eye that are usually slightly attached to each other. Adults have a band of small spines along the lower part of the mouth and small spots on the middle fins.

The victims of this species are poisoned when the tegmental sheath is depressed and it penetrates into the victim. This process tears the glandular tissue allowing the venom to escape and spread into the body of the victim.


Ecology and habitat

Lionfish have a stronger ecological effect on native fish, as they normally feed upon the same preys as the native species. Mainly due to this characteristics they are a huge threat to native coral reef fish communities.

Lionfish preferentially inhabit coastal waters and muddy regions, close to mangroves, in seagrass meadows, on the outer slopes of coral reefs or even on rocky bottoms. The occurrence of this species is dictated in part by the occurrence of its prey, that is one of the reasons why they can be found in depths that vary from 1 to 1000 meters deep.


The lionfish can be found in the Indian Ocean, from the Red Sea to south of Port Alfredo, in South Africa and Sumatra, in Indonesia, and now that this species migrated, can be found in the Atlantic Ocean and the Mediterranean Sea.

Studies report its occurrence in the United States after its introduction, which facilitated the spread of the species to Bermuda, Jamaica and Puerto Rico.


Pterois miles is a gonocoric species, it presents sexual dimorphism between male and female during the sexual period, where the male becomes darker and the female paler. Lionfish reach sexual maturity at about two years of age and studies suggest that it reproduces during all seasons of the year.

When the male is ready to mate, it performs nuptials dances for the female, always circling her before sunset and extending more intensely until the night and finally taking her to a substrate (it may be in reefs). The male becomes very aggressive against other males.

After these nuptial dances, the female lays two gelatinous and floating balls with thousands of eggs and the male quickly deposits sperm in the eggs’ balls in order to fertilize them. After fertilization, the eggs ascend to the surface and the parents separate. 12 hours after, it is already possible to distinguish the eyes and tail of the embryo. Juveniles are born after a few days and they pass their larvae faze floating on the surface of the water.


There are no records of potential threats to this species. Ectoparasites are considered the only documented problem this species.


  • The stomach of Pterois miles can expand 30 times in volume when it ingests a big prey or larger quantity of food.
  • Lionfish is a concern in places considered invasive for coastal managers because of their potential threat to fisheries resources, native fish communities and human health.
  • Despite being a dangerous fish, it is sold for ornamentation in aquariums.
  • This species can survive and proliferate in places with a minimum temperature of 10 C
  • This species occurs in Mozambique, but it is not consider a invasive species here.


Morris Jr, J. A., Akins, J. L., Barse, A., Cerino, D., Freshwater, D. W., Green, S. J., … & Whitfield, P. E. (2009). Biology and ecology of the invasive lionfishes, Pterois miles and Pterois volitans.

Bariche, M., Torres, M., &Azzurro, E. (2013). The presence of the invasive Lionfish Pterois miles in the Mediterranean Sea. Mediterranean Marine Science14(2), 292-294.

Turan, C., Uygur, N., &İğde, M. (2017). Lionfishes Pterois miles and Pterois volitans in the North-eastern Mediterranean Sea: Distribution, Habitation, Predation and Predators. Natural and Engineering Sciences.



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