Diagnostic Description
(
Anglèis
)
fornì da Fishbase
Body fairly elongate, more `herring-like' than `shad-like'. Total gill rakers 59 to 155 (as in A. caspia), thick, coarse and shorter than gill filaments in some, long, thin and equal to or longer than gill filaments in others (i.e. A. kessleri volgensis). Teeth well developed in both jaws. Other Caspian shads have less than 50 gill rakers, except A. caspia which is deep-bodied.
- Recorder
- Crispina B. Binohlan
Diseases and Parasites
(
Anglèis
)
fornì da Fishbase
Caligus disease. Parasitic infestations (protozoa, worms, etc.)
- Recorder
- Crispina B. Binohlan
Diseases and Parasites
(
Anglèis
)
fornì da Fishbase
Mazocraes disease. Parasitic infestations (protozoa, worms, etc.)
- Recorder
- Crispina B. Binohlan
Life Cycle
(
Anglèis
)
fornì da Fishbase
Spawns in rivers. Some enter with ripe gonads and spawn in the lower reaches or even delta (A. kessleri volgensis), others enter unripe and reach as much as 500 km upstream. The young descend in late summer and autumn.
- Recorder
- Crispina B. Binohlan
Migration
(
Anglèis
)
fornì da Fishbase
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.
- Recorder
- Crispina B. Binohlan
Morphology
(
Anglèis
)
fornì da Fishbase
Dorsal spines (total): 0; Analspines: 0
- Recorder
- Crispina B. Binohlan
Trophic Strategy
(
Anglèis
)
fornì da Fishbase
Euryhaline, anadromous, northward migration in spring (March/April), but sometimes as early as February or even January), a little distance from the shore. No feeding by A. kessleri kessleri during migration up rivers whereas A. kessleri volgensis feed en route.
- Recorder
- Crispina B. Binohlan
Biology
(
Anglèis
)
fornì da Fishbase
Pelagic at sea, found in a wide variety of habitats. Migrates to middle reaches of large rivers, spawning close to shores in main channel and in almost still water bodies such as river bays and eddies and flood plains, at 4-5 years. Enters rivers with unripe gonads. Some spawn 2-4 seasons with most females dying after spawning. Spawners appear along the coast in March to April, entering rivers April to May when temperature reach about 9°C, peaking at 12-15°C. Duration of spawning originally lasting 30-50 days; it starts in may to August when temperature rises above 15°C and lasts as long as it remains at 15-23°C; it is most intensive between 4-10 p.m. Eggs are bathypelagic. Spent individuals return back to the sea to feed. In autumn, the fish move to the southern part of the sea to overwinter. Juveniles migrate to the sea or estuarine during the first summer until maturity (Ref. 59043). Feeds chiefly on small fishes, less frequently on insect larvae and crustaceans (the latter though being the main food for A. kessleri volgensis) (Ref. 10432). Two subspecies known. The flesh of A. k. kessleri is said to be the tastiest of all Caspian clupeids owing to its high fat content, averaging 18.9% by weight before the spawning period, diminishing to about 1.5% after spawning (Ref. 10432). Impoundment of main rivers significantly reduced available spawning sites and migration routes; heavy overfishing may have caused all population decline during the first decades of teh 20th century. Most spawning grounds were upriver of Volga and now are no longer accessible (Ref. 59043).
- Recorder
- Crispina B. Binohlan
Importance
(
Anglèis
)
fornì da Fishbase
fisheries: commercial
- Recorder
- Crispina B. Binohlan
Alosa kessleri
(
Anglèis
)
fornì da wikipedia EN
Alosa kessleri, also referred to as the Caspian anadromous shad, the blackback, or the black-spined herring, is a species of clupeid fish. It is one of the several species of shad endemic to the Caspian Sea basin.[1]
This is an anadromous species which ascends from the Caspian to the Volga river up to the Volgograd to spawn. Before the construction of the Volgograd dam it migrated up to the Kama and Oka tributaries. Few fish enter the Terek and Ural Rivers.[1]
While the migration upstream is broken, it seems the fish have found new breeding grounds south of the dam, and the population is now abundant.[2] The species may be threatened by commercial and illegal fishing in the Caspian Sea and at the mouth of the Volga during the migration, though.[2]
See also
References
- licensa
- cc-by-sa-3.0
- drit d'autor
- Wikipedia authors and editors
Alosa kessleri: Brief Summary
(
Anglèis
)
fornì da wikipedia EN
Alosa kessleri, also referred to as the Caspian anadromous shad, the blackback, or the black-spined herring, is a species of clupeid fish. It is one of the several species of shad endemic to the Caspian Sea basin.
This is an anadromous species which ascends from the Caspian to the Volga river up to the Volgograd to spawn. Before the construction of the Volgograd dam it migrated up to the Kama and Oka tributaries. Few fish enter the Terek and Ural Rivers.
While the migration upstream is broken, it seems the fish have found new breeding grounds south of the dam, and the population is now abundant. The species may be threatened by commercial and illegal fishing in the Caspian Sea and at the mouth of the Volga during the migration, though.
- licensa
- cc-by-sa-3.0
- drit d'autor
- Wikipedia authors and editors