By Obiabin Onukwugha
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting tail (abdomen).
They are generally covered with a thick exoskeleton, and have a single pair of pincers. There are different types of Crabs species such as the red crab, fiddler crap, and giant crabs, amongst others.
Most species live in coastal areas of salty, fresh or brackish water. During movement, they either walk or crawl with gait. Crabs like other crustaceans, are omnivorous and act as scavengers, but many are predatory and some are vegetarian.
Crabs size may span nearly 4 metres (12 feet), 43 cm (17 inches), 46 cm (18 inches) and weigh well over 9 kg (20 pounds), depending on its specie.
According to researchers, like other macro-invertebrates, crabs are non-migratory, spending their entire lives in a small area. Thus they often show the effects of habitat alteration. They are good indicators of environmental health, particularly that of streams and other waterways.
Crab also can be sampled and identified with simple equipment, making them especially convenient for environmental bio-monitoring.
Researchers say, pregnancy in female crabs only last one or two weeks. Then they lay between 1,000 and 2,000 eggs.
When hatched, the young crab known as the zoea, is a minute transparent organism with a legless, rounded body, that swims and feeds in the plankton.
After casting off its skin several times, the enlarging crab passes into a stage known as the megalopa, in which the body and limbs are more crablike, but the abdomen is large and not folded up under the thorax.
After a further molt the animal assumes a form very similar to that of the adult. There are a few crabs, especially those living in fresh water, that do not pass through a series of free-living larval stages but instead leave the eggshell as miniature adults.
The average lifespan of a crab is 3 to 4 years.
Called “nshịkọ” in Igbo, “akan” in Yoruba and “kaguwa”, crabs are very delicious.
Scientists say, crab is packed with protein, which is important for building and maintaining muscle. Crab also contains high levels of omega-3 fatty acids, vitamin B12, and selenium. These nutrients play vital roles in improving general health while helping prevent a variety of chronic conditions.
In the Niger Delta riverine communities, crab called “Olu” or “Alikorogh”, is a delight in many dishes. The popular fisherman soup in Rivers State is not complete without the crab.
Crabs can also be well garnished, boiled and eaten as appetizers. This explains why they are very expensive, selling at the rate of N1,0000 to N5,000 per portion depending on the size and specie.
In the African folktale, the story of the crab and the tortoise explains why hatred runs deep.
It was said that in the animal kingdom, everyone knows that the crab are tortoise are sworn enemies.
Then one morning on the seashore they decided to fight to see which was the stronger, but, as both of them are protected by a hard shell, neither could succeed in injuring the other.
After a day-long bout, the duo came to an agreement that they were equal in strength.
“We are so well protected by our armor that no one can harm us,” said the tortoise. “
“And thus, we are the strongest creatures in the world,” said crab.
But while both of them were there boasting, a boy passed by and picked them up.
It was said that when the little boy took then home, the boy’s parents boiled the tortoise and his shell was made into ornaments while the crab was used to prepare a stew for his supper.
Since that day, the descendants of the two boasters have always been ashamed to meet, and that is why they always shun one another.
Crabs are said to have also played a significant role in human culture and mythology for centuries. From Chinese mooncakes to Native American purification rituals, the crab has been a symbol of protection, defense, purification, and grounding.
In Chinese mythology, the crab is associated with the moon and is considered a symbol of yin energy, in Hindu mythology, the crab is associated with the god Vishnu, in Native American mythology, the crab is associated with the zodiac sign of cancer, in Greek mythology, the crab is associated with the constellation of cancer, in African mythology, the crab is associated with the trickster god Anansi, while in Japanese mythology, the crab is associated with the god Ebisu.