What fish are "keystone" species?
1 Answer
Several anadromous fish and sharks are examples of keystone species.
Explanation:
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance.
Many wildlife species feed on several life history stages of anadromous fish. Anadromous fish are fish born in fresh water, but spend most of their lives in sea water. They return to fresh water to spawn, e.g. Salmon, smelt and stripped bass.
Availability of anadromous fish is critically important for survival or reproduction of several wild life species. Certain anadromous fish are keystone food resources for vertebrate predators and scavengers. Thus they are ecologically significant link between aquatic and terrestrial ecosystem. The spatial distribution of an anadromous fish in fresh water has important consequences for wild life biology and conservation of biodiversity.
Pacific salmon die after spawning and this brings important nutrients to the place where they are born. Their death provides food for many species in the area.
Sharks help control populations of sea turtles and dugongs who may cause overgrazing of sea grass. Since sea grass is where fish lay their eggs, overgrazing would lead to fewer fish.
Fish play a critical role in maintaining the structure of an ecological community. They affect other organisms and determine the types and number of various other species in the community. An ecosystem may experience a dramatic shift if a keystone species is removed.
