For the past twenty years they are many
evolutions of several fish and
crab
farming methods. Each of the farming methods has their own advantages and
weaknesses. From year to year
the crab is farmed using different methods and
the first farming process using self-regulating systems combined with
photosynthetic processes. After that more and more farming methods have been
built to farm crabs with more efficient and effective ways. They can be applied
in many different areas including smaller areas which before are not suitable
to farm crabs. But now with modern technologies, crabs farming become easier
and reliable.
4 Types of
crab farming that available
1.
Pond system or irrigation ditch
This is the most basic type of crab farming as well as the oldest. This
kind of system duplicates a fish habitat on an inland site. The size of the
ponds should be large since it need to be designed to support higher density of
the live stock.
2.
Fry farming system
It is also one of the oldest types to farm
crabs beginning since 17
th century. This kind of system basically
built culverts which used to link water and the crabs from a nearby stream and
then allow these crabs to growing up in a closed system. The crabs are feed on abundant
artificial food sources.
3.
Cage system
This system uses net or large cage to keep
crabs in high densities. Based on that system alone, this kind of crab and
fish farming is the most toxic one compared with the rest of the crab farming system.
4.
Integrated recycling system
This is one of the best ways to raise crabs
since this system minimizing the use of natural water resource. It uses large
tanks located in the greenhouse and the crabs are supplied with food sources as
well as nutrients.
Popular mud
crab farming in Indonesia
Mud crabs is one of the most popular types
of crab that often farmed in Asia countries. The mud crab is famous for
domestic trade or export import transaction due to the high demand in seafood
industry. You can say that the mud crab is economically very important because
this species can be found in most regions of the world.
Mud crabs are varied in terms of shell
colors from deep mottled green to dark brown. In the fish and shrimp
aquaculture system, crabs farming is considered to be the second important. Mud
crabs have a good market demand in fish industry and farmers who raise and sell
this type of crab can expect a greater profit from mud crab business
transaction compared with other types or species of crab. Mud crabs that
usually in high export market demand is the one with the size more than 15 cm
and weight of 500 gr. They are preferred sizes and weight for export import.
Two
edible mud crab types to be consumed
They are two most popular types of crabs
that often being consumed by people around the world are the green mud crabs
and the red
claw crabs. These two crabs are edible and often used for
commercial purposes. They are popular because of the quality of the taste,
meat, and size. They are high in marked demand and sold in quite higher prices
compared with other types of crabs. That’s why there are so many farmers show
interest in farming these two types of crab species.
The mud crabs can grow up to 22 to 24 cm in
size and they can offer 2 to 2.5 kilograms of weight. As for the female crab,
they tend to attain sexual maturity in a size of 12 to 13 cm already.
For your information, the lifespan of the
crabs are depends on the species. Below are some information regarding the
prediction of the lifespan of crabs for different species which we think it is
important to understand:
-
Horseshoe crab: They can live
up to twenty years mostly.
-
Blue crab: They can live
shorter, just for one to eight years mostly.
-
Dungeness crab: They can live
up to ten years mostly.
-
Hermit crab: This type of crab
has the longest lifespan compared with the other three because hermit crab can live
thirty to seventy years mostly.
Aquaculture
practices in mud crab farming
Many farmers are interested in raising mud
crabs for commercial purposes. They are also often farmed in Asia countries.
Moreover, they are two types of farming methods that mostly used by these
farmers: pond system/ grow out system and fattening system. Here are some of
the detailed explanations of these crab farming
systems:
1.
The pond system
In this system the young
crabs are kept to grow for about 6 months until they can reach desired weight
as well as size and ready to be sold in the market. They are raised with pond
based which build with details of pond construction, foods, and many more. The
ponds need to be selected and built carefully in order to raise high quality
mud crabs. The ponds also need to guarantee that the crabs are not going to
escape from the ponds.
2.
The fattening system
There are basically two
fattening systems which can be done by the farmers:
-
The first one is called pond
fattening system which the farmers set the size of the pond from 0,025 ha to
0.2 ha and the suitable tidal deep for the pond is about 1.5 meter.
-
The second one is called pen or
cage fattening system which can be done by using floating pens or cages instead
of select and built ponds. The cages can also being built using bamboo. The
cages are positioned in the shallow waterway with great tidal water flow.
Brackish water are recommended to raise
crabs in fattening system since the mud crabs are species that have high
tolerant to various salinity conditions. And if we want to compare these two
crab farming system, then the fattening
system is considered to be more profitable than the pond system because raising
crabs using the second one takes less time than the grow out crabs farming
system.