The Antarctic silverfish (Pleuragramma antarctica), or Antarctic herring, is a species of marine ray-finned fish belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Southern Ocean and the only truly pelagic fish in the waters near Antarctica.[2] It is a keystone species in the ecosystem of the Southern Ocean.[3]
| Antarctic silverfish | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Nototheniidae |
| Genus: | Pleuragramma Boulenger, 1902 |
| Species: | P. antarctica |
| Binomial name | |
| Pleuragramma antarctica Boulenger, 1902 | |
While widely distributed around the Antarctic, the species appears to have largely disappeared from the western side of the northern Antarctic Peninsula, based on a 2010 research cruise funded by the National Science Foundation under the US Antarctic Program.[4]
Taxonomy
The Antarctic silverfish was first formally described in 1902 by the Belgian-born British zoologist George Albert Boulenger with the type locality given as Victoria Land in Antarctica.[5] It is the only species in the monotypic genus Pleuagramma which was also described by Boulenger.[6] Some authorities place this taxon in the subfamily Pleuragrammatinae,[7] but the 5th edition of Fishes of the World does not include subfamilies in the Nototheniidae.[8] The genus name is a compound of pleuro meaning "side" with a which means "without" and gramma meaning "line", an allusion to the absence of a lateral line.[9]
Description
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] This Antarctic marine fish is one of several in the region that produce antifreeze glycopeptides as an adaptation against the extreme cold of Antarctic waters.[10]
Ecology
The postlarvae, 8–17 mm (0.31–0.67 in) in size, feed on eggs of calanoids (Calanoida), sea snails Limacina and tintinnids (Tintinnida).[11] The postlarvae live at depths of up to 135 metres (443 ft).[2] Juveniles feed on copepods (Copepoda), mostly on Oncaea 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 as Adelie penguins, marine flying birds and Weddell seals.[13]