Tuesday, 29 December 2015

Life development of an egg of a prawn

At first the ovum will be like a “cell” then after it can be split into many cells and it becomes ovum.  This consecutively taken place then after many months when the egg becomes ovum during 13-14hrs the larva called Nauplius will be exited out from an egg like that we can see many stages in prawn growth.  There is a chance of getting big loss at the stage, there are some more growth stages will be seen.  In each stage the growth will be finished easily. The growth of prawns in many stages will be seen below.

Nauplius (1-3stages)
The first Nauplius larva stage has the ability to swim in water rapidly.  It actually grown well and have their egg as food. Within few hours it will moult, and the Nauplius will attain the second stage.  It consecutively moult and attains the stage of 3rd 4th  and 5th  within 32 hours the sixth stage of larva will be exited out.  This Nauplius and larva (1st and 6th are small in size.0, 34-0,51mm length) at each stage Moulting of Nauplius larva there will be a change in shape of body (fig-2).   At sixth stage of Nauplius larva will have their egg as a food but it won’t have the Phyto planktons in sea.  If in case it will have the situation to eat, the survival power will be decreased.

Zoea Larva (3 stages)
At sixth stage of Moulting the Nauplius will be getting Zoea larva in this there are 3 stages of growth will be seen. This larva has 3 parts head, angina and stomach. Zoea larva will have their food as Phyto planktons these will be exited out in season if we didn’t find any Phyto plankton their life will become dangerous. Generally, during the season in prawns breeding then after that it will find the enough food for their living .Though these things have the Phyto plankton in this one part will have the fish species we cannot avoid it.

Mysis Larva (2 stages)
The third stage of zoea larva will be moulted then it will appear the first stage of mysis larva.  It consists of two stages the structure can be seems like the growth of the prawn can be done well.  The larva head part and chest part will be joined together and it is covered by a Carapace. Although the Rostrum can be grown well, the adolescence of larva unstable walking will be grown up.  The length of the mysis larva will be 3.10 to 4,5mm.

Post Larva
After moulting the third stage of mysis larva will be changed to post larva.  Now, in this if the swimming legs will be appeared so it can be activated.  Already, appeared of walking legs will be used for walking and it can be used for capturing food.  In this stage, these planktonic retired their lived life in sea upper bottom water level.  It will change to the situation of bottom water level and the continuation of Moulting.  Feeding, the ability of changing into flesh and according to this soon it will grow and become big prawn.

It will get the structure of prawns at the stage of juveniles, to grown up their life volunteer it move from sea and enter into brackish river water.  These can be saved in this season in which brackish river water in what season we can find out the juveniles will be the important of business secret.  To know this, we cannot say that it done only by the researchers.  This experience can be well known by the fisherman friends.  Their importance is not known this can be taught to them to get the bond of juveniles.  This can be found in which season will be detailed spread due to this we cannot save juveniles.

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