Photo by Peter Southwood
Photo by Peter Southwood
This fish occurs from 20 to 400m depths, and is, according to Smiths', well known from trawls from the Cape to Delagoa Bay. Smiths' gives the maximum size as 60 cm, but fishbase gives a whopping 1.5 m and 16 kg maximum weight! It is an Indo-West Pacific species, and, given the number of hits from japanese websites, seems to be an common catch for that country, where it is called the Japanese Bluefish, rather than the odd gnomefish (and at 1.5m length I wouldn't quite call it a gnome!)
Peter saw this fish during a night dive, but I have recently seen a small school during the day at Windmill. I could not approach them anywhere near as close as Peter did, as shown in his two excellent photos. The pink area along the back is probably the remains of a wound.
While superficially the juveniles are similar to other schooling fishes like sardines and anchovies, the latter two are more slender and only have a single dorsal fin. Mullet are also similar, and have two dorsal fins like the gnomefish, but they are set further back along the body.
For more images of this fish go to fishbase or the link given in the references below.
Smiths' Sea Fishes, MM Smith and PC Heemstra, 1986.
www.fishbase.org
fishpix.kahaku.go.jp