By ingo 
“
( by LKW, 2005)
The inhuman creatures were found on my field work of environmental research along the seashore wetlands. They kept waving big claws constantly as if provoking: “Come on, come on!” “
This is Uca, also known as fiddler crab, with its chateristic uneven big claw. They like to constantly wave those big claws in front of their holes. Oddly, each male crab has only one big claw. Does it look like running around with a fiddle on one side?
Only the male crab have big claw on the left or right side. The crab of right or left big claw tend to pick fight with each other from time to time. The fight however is accordingly square because, when the left and right meet face to face , it is big side against another big side. No one would take advantage of other
The big claw is called mating pincer, bright colors with special patterns. The other one is very small and called feeding pincer. It is used to scrape the surface of the mud rich with algae and other organic matter into the mouth. If the male crab unfortunate loss its big claw, a small one will grow at the original place while the other small claw will grow into the big one as the replacement. The body of female crab is smaller than male one. Two claw are equal small and symmetrical for feeding purpose. The color of the male is more attractive than the female, which includes coral, bright green, golden and light blue.
The crab has the habit of dancing in the high tide, which contains many meanings, such as warming when other male crab approached its teretory. The “landlord” usually shakes the big claw as a warning signal; or uses the big claw to trike its own shell or mud on the ground, through the sound, issues a warning. Sometime, the big claw is a tool to ask a love. There are several kinds of Uca use their claws to attract female crab into their habitant holes. If two male crabs compete for one territory or the opposite sex, the big claw will become a powerful wrestling weapon. The victory one will push the female into the bridal chamber doing ‘works”.
This interesting ecology is across the tropical and subtropical seashores. The ability of digging holes by Uca significantly changed the micro terrain and soil properties, helping a lot of wetland conservation.
Now we welcome you watching this micro-documentary, know more about the interesting fiddle crabs.
iNGO Academy
by Louis K Wang