Movement of fish from their home range habitat to other habitat mainly for Breeding is known as Fish Migration.
Their Migration is classified in different ways:
ON THE BASIS OF HABITAT
- ANADROMOUS MIGRATION
In this Migration mainly fishes living in sea and migrate to freshwater (river) for egg laying.
EXAMPLE: HILSA, ACIPENSER, SALMON.
- CATADROMOUS MIGRATION
In this Migration fish mainly live in rivers and migrate to sea for egg laying.
EXAMPLE: Anguilla is found in European freshwater river to reach in the sargasso, and bermuda for egg laying,it travels 7000 miles.
- POTAMODROMOUS MIGRATION
In this Migration fish migrate from freshwater to freshwater and fined their Spawning grounds. After laying eggs these returned to feeding ground.
EXAMPLE: Carps and Trouts travel long distances in large reverse for Spawning.
- OCEANODROMOUS MIGRATION
In this Migration fish migrate from one place to another in the ocean (sea to sea).
EXAMPLE: Tuna, Herring fish , Travel long distances in the sea for egg laying.
ON THE BASIS OF DIRECTION
- LATITUDINAL MIGRATION
In this fish move towards north in spring and south in autumn.
EXAMPLE: Sphyra and Swordfish.
- VERTICAL MIGRATION
In this fish move up and down daily. It is shown by deep water fish.
ON THE BASIS OF PURPOSE OF MIGRATION
- CLIMATIC MIGRATION
In this fish move to search for a more suitable climatic condition.
- GAMATIC MIGRATION
In this fish move for reproduction.
- OSMOREGULATORY MIGRATION
In this fish move for maintaining proper osmoregulation in their body.
- ALIMENTAL MIGRATION
In this fish move for searching food and water.
Adult fish migrate from feeding ground to Spawning ground for laying eggs. From eggs young once come out which live in the Spawning ground and go to nursery ground , where they become juvenile and these young stage fish go to adults feeding ground. Where they become mature and move to the Spawning ground for next generation.
Migration patterns are related to water current. Young stage drift with the current to the nursery ground .
Spawning Migration against the current and fish agent to return to the feeding ground with its current .
The Migration with is current is called Dentant movement and Migration again water current is Contrantant movement.
- Migration is an adaptation of large number of population of fish, because a particular ground may not have in a food, a survive both larva adult members, hence there is separation of nursery, Spawning, feeding ground. Which is possible by Migration.
- Due to Migration there is a suitable condition are provide for young once, hence to better survival of eggs and Youngs parent go to Spawning ground from their home range. After Spawning they come to their feeding ground.
- In some cases, due to Migration parent care is also seen male and female member or both.