Common Lionfish

Introduction

The Common Lionfish is a spectacular looking fish that has 13 venemous dorsal fin spines.

Identification

The Common Lionfish has very long pectoral and dorsal fins. The body is covered with red to black bands on a pale background. Adults often have white spots along the lateral line. A tentacle is usually present above both eyes. The tentacle is variable in size and shape, usually long in juveniles and leaf-like in adults.

The species looks very similar to the Spotfin Lionfish, Pterois antennata, which has a similar distribution in Australia. The two species can be distinguished by the shape and colour of the pectoral fins. The fins of P. volitans are more pointed and covered with variable spots and bands, while P. antennata has more rounded fins which are white to gold in colour.

Other differences include the pectoral ray count, which is 14-16 in P. volitans and 16-17 in P. antennata. The scales of P. volitans are cycloid but in P. antennata they are mostly ctenoid. The lateral scale rows number 90-120 in P. volitans and 50-54 in P. antennata.

Distribution

It is a tropical species found widely throughout the Indo-Pacific. In Australia it is known from south-western Western Australia, around the tropical north of the country and south to the southern coast of New South Wales.

It is now a pest species in parts of the Western Atlantic and Caribbean.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.

Predators

The following text is taken from Albins and Hixon (2008). "Lionfish may be cannibalistic, but otherwise have few documented natural predators in their native range (Bernadsky & Goulet 1991). While it is important to mention that extensive studies of predation on lionfish have not been reported, the apparent paucity of natural predators may be due, in part, to the defensive dorsal, anal, and pelvic spines of lionfish, which deliver a potent venom that may be fatal to fishes (Allen & Eschmeyer 1973)."

Danger to humans

The species has extremely venomous fin spines. All 13 dorsal fin spines, 1 pelvic fin spine and 3 anal fin spines are venomous. The pectoral and caudal fins are not toxic because they lack spines. When disturbed by a diver, the Common Lionfish often makes little effort to swim away. Instead it points its dorsal fin spines towards the intruder.

References

1. Albins, M.A. & M.A. Hixon, 2008. Invasive Indo-Pacific lionfish Pterois volitansreduce recruitment of Atlantic coral-reef fishes. Marine Ecology Progress Series. 367: 233–238.
2. Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.
3. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
4. Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
5. Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.
6. Myers, R.F. 1999. Micronesian Reef Fishes. Coral Graphics. Pp. 330.
7. Randall, J.E., Allen, G.R. & R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press. Pp. 557.