Tuesday, July 21, 2015

Pitcairn Islands 2015
Red Lionfish (Pterois volitans) - Scorpionfish

The red lionfish (Pterois volitans), also known as the scorpionfish, firefish and turkey fish, is a tropical coral reef fish found in the Indo-Pacific region, reaching as far east as French Polynesia. It has now become a potential threat on the Atlantic coasts of the USA and in the Caribbean through accidental introduction. It prefers a habitat with water temperatures of between 22°C and 28°C and swims at the depth range of 10 to 175M. It favours coral reefs and rocky outcrops, although it has been observed over coral patches, near sandy bottoms and in mangrove, seagrass and even canal habitats. It is also found in lagoons and harbours.

Red lionfish are visually stunning, being clad in white/cream stripes alternated with red, maroon and/or brown stripes. These vertical stripes alternate from wide to very thin. Adults in this species can grow from 38 - 47 cm in length. As with many species within the Scopaenidae family, it has large, venomous spines that protrude from the body, similar to a mane, giving it the common name lionfish. The venomous spines make the fish inedible or deter most potential predators, of which very few are known. The average red lionfish lives around 10 years. Lionfish venomous dorsal spines are used purely for defence and when threatened, the fish often faces its attacker in an upside-down posture which brings its spines to bear. However, its sting is usually not fatal to humans although if stung humans will experience extreme pain and possibly headaches, vomiting, and breathing difficulties.

The species is an ambush predator that preys on small and juvenile fish, crustaceans (crabs and shrimps), molluscs and isopods. It uses its oversized, ornate pectoral fins to herd and ambush small reef fishes and crustaceans. They are relatively quick to adapt to novel prey types, and quickly learn to avoid toxic prey. Lionfish stomachs can expand over 30 times in volume when consuming a large meal and they are capable of long-term fasting and are able to withstand starvation for periods of over 12 weeks without mortality.

Pterois volitans, through their voracious feeding, ability to target prey, rapid reproduction and lack of predators, have become an invasive species in certain areas and can threaten fragile ecosystems. This threat to the diversity of coral reef areas is of concern to Pitcairn and its isolated and beautiful islands of Oeno and Ducie.

stamp images and description thanks to: