Least Cisco

Body elongate, somewhat compressed laterally, greatest body depth at front of dorsal fin. Head about 19 - 24 % of total length; eyes large; snout length usually less than eye diameter; mouth moderate, terminal, lower jaw always protruding, maxillary at a distinct angle, extending posteriorly to below anterior half of the eye; a small cluster of teeth present on the tongue. Overall coloration silvery, usually brown to dark green on the back, becoming silvery on sides and below. The small non-anadromous form that remains in fresh water is without spotting on the back and only the pelvic fins have black pigment on the tips., the remaining fins are unpigmented. The larger, anadromous form has dark spots on the head, back, dorsal, and adipose fins, and sometimes, on the pectoral fins; all fins have usually dark pigment on the tips.

Spawning occurs at night, peaking between 8 pm and midnight. A female spawns almost vertically upward, with her ventral side upstream. She is joined by as many as five males who swim vertically and close to her. As the spawners approach the surface, eggs and milt are released. The fish break the surface, fall over backward, and swim back to the bottom of the pool (Ref. 27547).

Anadromous. Fish that ascend rivers to spawn, as salmon and hilsa do. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 0; Dorsal soft rays (total): 12 - 14; Analspines: 0; Analsoft rays: 10 - 13; Vertebrae: 58 - 64

Occurs in coastal waters, estuaries, large lakes and rivers (Ref. 5723). Lake-dwelling populations appear to be non-migratory, while those found in streams or brackish water move considerable distances to reach or leave spawning sites (Ref. 27547). Nerito-pelagic (Ref. 58426). Feeds on planktonic crustaceans and insects (Ref. 1998); also plant material (Ref. 27547) and fishes (Ref. 58426). Does not usually feed during its spawning run (Ref. 28219, 28860, 28861). Migratory forms are observed to live longer than fresh water forms (Ref. 1998).

Adults occur in coastal waters, estuaries, large lakes and rivers (Ref. 5723). Lake-dwelling populations appear to be non-migratory, while those found in streams or brackish water move considerable distances to reach or leave spawning sites (Ref. 27547). Semi-anadromous populations forage in estuaries, lower courses of rivers, backwaters and lakes (Ref. 59043). Nerito-pelagic (Ref. 58426). Feed on planktonic crustaceans and insects (Ref. 1998); also plant material (Ref. 27547) and fishes (Ref. 58426). Do not usually feed during its spawning run (Ref. 28219, 28860, 28861). Migratory forms are observed to live longer than fresh water forms (Ref. 1998). Spawn in deep pools on sand and gravel (Ref. 59043). Flesh is said to be tasty (Ref. 1998).

fisheries: commercial; gamefish: yes

Coregonus sardinella, known as the least cisco or the sardine cisco, is a fresh- and brackishwater salmonid fish that inhabits rivers, estuaries and coastal waters of the marginal seas of the Arctic Basin, as well as some large lakes of those areas.

In North America it is found from the Murchison River (Nunavut) west through the Bering Strait to the Bristol Bay (Bering Sea) in Alaska, and in the Russian Arctic from the northern part of the Bering Sea across the Siberian Arctic coast to the Kara Sea and Kara River and further to the Pechora River drainage on the European side. It has been introduced in some lakes and rivers in Uzbekistan and Kazakhstan.

Coregonus sardinella is closely related to the European cisco or vendace Coregonus albula, and also is close to the Siberian peled whitefish C. peled. Most recently, it has been argued to be the same species as the European cisco.