Eastern Blue Groper, Achoerodus viridis (Steindachner, 1866)
Despite the name, the Eastern Blue Groper is not a groupers, but a wrasse. It lives in shallow coastal waters and is regularly seen around exposed reefs.
This stout bodied species has peg-like teeth, heavy scales, a large tail and thick lips. Juveniles are brown to green brown. Adult females are brown to reddish-brown. Each scale may have a darker red spot. Adult males are bright blue, hence the common name. The blue can range from deep navy to cobalt blue, and there may also be darker or yellow-orange spots or lines around the eyes.
Adults are found in a wide range of habitats from shallow waters, down to 40 m. Juveniles are usually found in estuarine seagrass beds.
The Eastern Blue Groper is endemic to Australia. It is found in coastal, marine waters from southern Queensland to Wilson's Promontory, Victoria. It is particularly well known to scuba divers in New South Wales and was made the fish emblem for New South Wales in 1996.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information.
Feeding and diet
It is a carnivorous species. The video, below, shows an Eastern Blue Groper biting a sea urchin.
Life history cycle
Adults are found on rocky coastal reefs, they spawn during the winter (July-October) and the young recruit primarily into estuarine sea grass beds during winter (Gillanders, 1999). A full description of the Larval Eastern Blue Groper.
Like most wrasses, as the Eastern Blue Groper ages, it passes through several stages. Juveniles are all female. As the fish matures, it goes through an initial phase (IP) during which the fish could be either male or female. Adult females are reddish brown. Adult males develop bright blue colouration. These fish have reached the terminal phase (TP).
The Eastern Blue Groper is particularly susceptible to spearfishing and in the past was taken in large numbers by spearfishers. As a result, the species was given total protection status in New South Wales waters in 1969. In 1974, angling and commercial fishing were allowed again, but spearfishing was still prohibited. In 1975, concern over the large catches by commercial fishers led to a ban on bottom-set gill nets. Blue Groper was banned from sale in 1980.
Danger to humans
The species presents no danger to humans.
- Gomon, M.F & B.C. Russell in Gomon, M.F, J.C.M. Glover & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
- Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
- Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
- Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.