Crab / Mud crab (Scylla serrata) culture technique Or Mud Crab Scylla serrata fattening in bamboo cage : Part 01

Crab / Mud crab (Scylla serrata) culture technique Or Mud Crab Scylla serrata fattening in bamboo cage : Part 01

Introduction :

Mud crab Scylla serrata (locally called “Jati or Haba Kakra”) is widely distributed in the Bangladesh and one of the most famous culture species, which has great economic value. We can culture it in earthen pond, pen and even in cages. Mud crab fattening in cage is required and to be useful for high growth and low mortality. Unfortunately, crab fattening in cage is not widely practiced in Bangladesh because of lack of proper knowledge and publicity. There are 640 sps of crabs available in various aquatic environments; out of these crabs of Scylla sps are larger in size, fetches high price nd suitable for culture practices. The Scylla species popularly are known as the Mangrove crabs, the Mud crabs, the Green crabs and the Brown crabs. Crabs can be cultured in earthen dug out ponds, tanks and cages. There are two types of culture methods 1.Culture 2.Fattening. In culture method crab lets either brought from hatcheries or wild are stocked in and grown for 6-9 months. In fattening method grown up, 50-100 gm sized crabs are brought from wild and fattened in ponds, for 3-4 months. Here I will discuss overall technique of crab culture-

Cage making and placement:

Due to cheap price and availability, bamboo is widely used for preparing cage

  Ø  Cage dimension of 7¢ x 3¢ x 1¢.

  Ø  A cage was divided into 60 compartments or cells

  Ø  Each cell size should be 7² x 7² x 10².

Precaution:

Ø  Placed in such a way that, did not touch bottom during low tide.

Ø  Cage was provided with floats and rings at four corners and tied with wooden poles

Ø   Cage should remain afloat at least 1-1.5 inch above water.

Ø   The cage should covered with coconut fronds to prevent the crabs from direct sun.

 

 Stocking in cages:

Male and female crabs having soft shell were collected from natural source. In each compartment of cage, one female or male crab was stocked, (i.e. 60 crabs/cage). Stocking was done during early morning or late in the afternoon to minimize stress. 30 male (ranging from 160-400 g) and 30 female (ranging from 140-250 g) crab were stocked with one individual per cell.

Ideal parameter:

Salinity ‰ = 17-18

Water Temp. (°C)= 25=32

pH= 7.5.8.2

Feeds and Feeding:

Generally, fresh eel (Anguilla spp.) fish, chopped telapia was used as food for mud crab and when fresh eel was not available salted eel (Anguilla spp.) fish was given. The feed was supplied twice a day at 5% of body weight up to harvesting. 

Crab culture technique part 2