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单词 spawning ground
释义

spawning ground


Translations

Spawning Ground


Spawning Ground

 

the place where fishes deposit their roe. Sections of bodies of water that have rocky-gravelly bottoms or that are overgrown with vegetation serve as natural spawning grounds for fishes that deposit glutinous roe. Fishes with non-glutinous roe spawn in those parts of rivers or seas that usually have a swift current.

In order to improve conditions for reproduction among valuable commercial fishes whose path to spawning grounds is obstructed by hydrotechnical structures (usually in the higher course of rivers), artificial spawning grounds are established. For fishes such as sturgeons, salmon, trout, and whitefish, which deposit their roe on hard bottoms, pebbly or gravelly spawning grounds in the form of strips or beds are established in river channels at various depths; the spawning grounds are usually placed perpendicular to the shore. Special spawning canals are also provided for salmon. For fishes that deposit their roe on plants (domesticated carp, common carp, European bream, crucian carp, pikeperch, roach), stationary or floating spawning grounds are made from juniper and spruce branches, reed rhizomes, small trees, or shrubs (submerged in littoral zones). Stationary spawning grounds are attached to the bottom in shallows; floating ones, consisting of wooden frames with bundles of branches tied to them, are installed in relatively deep places by means of anchors. Artificial spawning grounds are also used to gather and destroy the roe of undesirable fishes. In pond hatcheries, the domesticated carp spawns in special spawning ponds.

G. V. NIKOL’SKII

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更新时间:2024/12/22 20:24:21