Silver GemfishThe gemfish, Novaculichthys taeniourus, is a species of perciform fish of the family Pseudochromidae, the dottybacks. The gemfish has a moderately elongate compressed body. The body is iridescent bluish above and silver below. Gemfish has large fang-like teeth at the front of the jaws, followed by a row of smaller compressed teeth. They have two dorsal fins followed by two separate finlets.
The head is short with large fang-like teeth at the front of the jaws, followed by a row of smaller compressed teeth in both upper and lower jaws. The dorsal fin starts behind the middle of the body and has 11 spines and 16-18 soft rays. The anal fin has 3 spines and 14-16 soft rays. The first to third dorsal spines, especially the second, are enlarged with a venom gland at their base.
The gemfish is found in the coastal waters of southern Australia, from central New South Wales to south-western Western Australia. The gemfish eats mainly crustaceans and small fish.
Gemfish is seen in groups over reefs at depths less than 20 meters (65 ft). They are oviparous and form distinct pairs when mating. The eggs are demersal and adhere to the substrate. The larvae are planktonic.
Parasites of the gemfish include "Pelecotrema koiae" on the gills, "Phyllodistomum lyonsi", a nematode in the intestine, and a Caligid copepod on the skin. The gemfish is sometimes taken in artisanal fisheries. It is marketed fresh, frozen, smoked, or dried salted, but are of inferior quality to the related pink snapper.
Aquaculture experiments have been carried out with this species both in Australia and overseas. Whilst the juveniles seem to adapt well to aquaculture conditions, growth rates and survival were low. The species has been recommended as marine ornamental fish for home aquariums.
The species was first scientifically described as "Centropomus taeniourus" by the French naturalist Charles Frédéric Girard in 1856 from a specimen collected from King George Sound off Albany, Western Australia. He published the description in 1859 in the Proceedings of the Academy of Natural Sciences of Philadelphia. Girard's name for the species was later changed to "Novaculichthys taeniourus".
The specific epithet is derived from the Greek "taenio-" meaning "ribbon" and "-ouros" meaning "ear". The genus name has been spelt as "Novaculites" and as "Ouvaculites" with the latter treated as a misspelling of "Ouvaculichthys" by some authors.
Global silver gemfish production
Global production of silver gemfish is estimated at approximately 1,200 metric tons per year. The vast majority of this total is produced in Asia, with China accounting for the lion's share. Other significant producers include Indonesia, India, and Vietnam.
There is no reliable data on silver gemfish stocks, making it difficult to assess the status of the species. However, it is thought that silver gemfish populations are in decline due to overfishing and habitat loss. In addition, silver gemfish is often caught as bycatch in other fisheries, further exacerbating the problem.
The future of silver gemfish appears uncertain at best. To ensure the survival of the species, it is essential that steps are taken to reduce fishing pressure and protect silver gemfish habitat. Otherwise, this once-abundant species may disappear from the oceans entirely.