How and why white feces syndrome occurs in shrimp pond?

Hello everyone:

  Today we will see about white feces syndrome occurance and what are the major cause of white feces disease in shrimp.

In most of the cases white feces syndrome is not occurs alonely in pond. It is a one type of additional disease. If any infection comes to shrimp hepatopancreas then it will leads to the white feces disease. You can note that if your shrimp affected by EHP and Vibrio then later white feces disease comes. We prevents the disease only by improving the hepatopancreas strength.

It occurs when the hepatopancreas of the Shrimp severely affects. 

White feces syndrome - white to yellow brown of feces strings floats on the surface of water or found in check tray. It have good buoyant capacity for floating.

Shrimp bottom have various wastes and various types of pathogens present. If shrimp eats from the bottom then all types of microorganisms present in the bottom will enter into the shrimp gut. So we have maintain good microflora in the shrimp gut.

AHPND or Early mortality syndrome:

It is mainly caused in shrimps due to the bacteria and also by some parasites. Vibrio also causes this disease. In this disease , the pathogen first affect the hepatopancreas in the body. Then it multiplies and causes severe death. Types of worm like vermiform and parasite called gregarine are the major cause for the disease.

You have to properly check the seed before buying.

Relation between AHPND and white feces syndrome:

    It is the important factor of white feces disease. In hepatopancreas, if the vermiform and gregarine infects more then it cause the sloughing of cells.

It is called aggregated transformed microvilli which is sloughed with the epithelial cells in the hepatopancreatic tubule.

Aggregated transformed microvilli

Sloughing of cells

Hepatopancreatic tubule

Everyone knows about microvilli - it majorly involves in absorptive function in hepatopancreas.

These gregarine, worm and bacterial infection will affect the microvilli. Then it also leads to the death of hepatocytes in the hepatopancreas. Then the hepatopancreas in white colour due to loss of pigmentation. These highly white coloured death cells moves via gut and shows white in colour and leads to white gut disease. Then the fecal matters comes out from the body in white colour. We called it is white feces disease.

Death hepatocytes in hepatopancreas

Moves via gut (white colour)

White feces

When the concentration of bacteria,worm and gregarine infection increases they take nutrients from host. ATM (aggregated transformed microvilli) concentration determines the white feces. 

Symptoms:

 Decrease in feed consumption, decrease in growth rate , white gut(necrosis of epithelial mucosa and haemocytic enteritis, movement of cell via gut shows white gut). It sometimes causes lesions in hepatopancreas. Floating of white or yellow fecal mates in pond.

White feces occurs if any damage in hepatopancreas and other hepatopancreatic related disease. In some early post larvae hepatopancreas functions may suddenly changes due to any parameters. We have to properly maintain it.

We can prevent by giving proper gut probiotics to the shrimp from earlier culture days. Quality of feed is very important.  Some protists also present as host for that worms and gregarine parasites. So proper pond preparation is very important for good culture. Some of research also going about the proper reasons for white feces.

Hepatopancreas is very important for shrimp. It is doing important function in shrimp likes digestive and absorptive function. It releases digestive enzymes. It stores nutrients for the animal. It provides energy for metabolism, molting, reproduction. Different types of cells in hepatopancreas doing various function. We will see briefly about hepatopancreas colour and different cells in the organ and how to improve the hepatopancreas function in next blog.

P.Dhivagar, BFsc, Tamilnadu.

Email: dhivagarfcri2000@gmail.com

ph: 9384346193