Fisheries level-2; semester-2 Aquaculture sheet theory( AQC 205)   19th batch


 

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 This sheet provide by nipu mam & istiyak sir for level 2 semester 2 student to 19th batch.. year 2022..

  SYMBIOSIS

The term symbiosis was first coined in 1879 by German botanist, Heinrich Anton De Bary, to describe the relationship between certain species of algae and fungi living together to form lichens Any animal or plant that spends a portion or all of its life cycle intimately associated with another

organism of a different species is considered as symbiont or symbiote and the relationship is

designated as symbiosis

There are four subordinate categories of symbiotic relationships that are commonly distinguished. Phoresis

Commensalism

Parasitism

Mutualism

Phoresis

The term phoresis means to carry. During this type of relationship, that which is usually the smaller of the two species- the phoront- is mechanically carried in or on the larger species- the host. No metabolic interaction or dependency occurs

An example of phoresis is the transport of bacteria on the legs of flies. The fly host provides only involuntary transportation for the bacteria. Although the fly host provides involuntary transportation for the bacteria, the life processes and welfare f both partners are not obligatorily dependent on what is essentially an accidental relationship.