| Antarctic silverfish | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Nototheniidae |
| Genus: | Pleuragramma Boulenger, 1902 |
| Species: | P. antarctica |
| Binomial name | |
| Pleuragramma antarctica Boulenger, 1902 | |
TheAntarctic silverfish (Pleuragramma antarctica), orAntarctic herring, is a species of marineray-finned fish belonging to thefamilyNototheniidae, the notothens or cod icefishes. It is native to theSouthern Ocean and the only trulypelagic fish in the waters nearAntarctica.[2] It is akeystone species in theecosystem of the Southern Ocean.[3]
While widely distributed around the Antarctic, the species appears to have largely disappeared from the western side of the northernAntarctic Peninsula, based on a 2010 research cruise funded by theNational Science Foundation under theUS Antarctic Program.[4]
The Antarctic silverfish was first formallydescribed in 1902 by the Belgian-born BritishzoologistGeorge Albert Boulenger with thetype locality given asVictoria Land in Antarctica.[5] It is the only species in themonotypic genusPleuagramma which was also described by Boulenger.[6] Some authorities place this taxon in thesubfamilyPleuragrammatinae,[7] but the 5th edition ofFishes of the World does not include subfamilies in the Nototheniidae.[8] The genus name is a compound ofpleuro meaning "side" witha which means "without" andgramma meaning "line", an allusion to the absence of alateral line.[9]
Antarctic silverfish usually grow to about 15 cm (5.9 in) in length, with a maximum of 25 cm (9.8 in). The maximum reported weight of this species is 200 g. Antarctic silverfish have a maximum reported age of 20 years. When alive, they are pink with a silver tint, but turn silver only after death. All the fins are pale. The dorsal side is slightly darker.[2] ThisAntarctic marine fish is one of several in the region that produceantifreeze glycopeptides as an adaptation against the extreme cold of Antarctic waters.[10]
Thepostlarvae, 8–17 mm (0.31–0.67 in) in size, feed on eggs ofcalanoids (Calanoida), sea snailsLimacina andtintinnids (Tintinnida).[11] The postlarvae live at depths of up to 135 metres (443 ft).[2] Juveniles feed oncopepods (Copepoda), mostly onOncaea curvata and can be found at depths of 50 to 400 m (160–1,310 ft),[11][2] while adults can be found at depths 0–728 m (0–2,388 ft).[2] As their size increases, so does the size of their prey items. Mature females may spawn for the first time at 7–9 years of age.[2]
Antarctic silverfish are the most abundant pelagic fish species in the High Antarctic shelf waters of the Southern Ocean[12] and are important high-caloric prey species for high-trophic animals such asAdelie penguins, marine flying birds andWeddell seals.[13]
