Migration

       Migration

-Migration term was given by  Calon 

- term derived from Latin word Migrare which means ' to travel '.

Defination :-  

                        it is defined as that migration   is a regular,periodic and two way movemen  of a population from breeding or nestling place to a feeding or resting place and come back

                     Migration in fishes

- Long journey taken by fishes from one place to another and come back is called fish migration.

Reason for migration :-

1. Sexual maturity 

2. Hormones

3. Instinct

4. predators and competition

5. scarcity of food 

6. Abiotic factor like light, ph, water ,temp. Etc.

Types of migration :-

1. Latitudinal Migration

2. Oceanodromous migration

3. Potamodromous migration

4. Catadromous migration

5. Anadromous migration

1. Latitudinal Migration:-        

                       The fishes like Xiphius gladus move towards North in spring  and South in Autumn.

2. Oceanodromous Migration:- 

Migration  of fishes within sea for breeding  from native place to far

3. Potamodromous migration:-

The long movement of fishes within the fresh water. 

4. Catadromous migration:-  

Migration of fresh water fishes from fresh water to sea water for spawning.                   

                                                                     5. Anadromous  migration:- 

The movment of marine fishes from sea water to fresh water .

www.knowledgeguru29.blogspot.com