Common Name: Red-Jointed Fiddler Crabs

Scientific Name: Uca minax

 

Kingdom: Animalia

Phylum: Arthropoda

Class: Malacostraca

Order: Decapoda

Family: Ocypodidae

Genus: Uca

Species: U. minax

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The Red-Jointed Fiddler Crab are chestnut colored crabs with a gray face. The male crabs have two claws, one a little larger than the other, while the female, have two normal claws. This particular crab as red joints. They have eight walking legs that can either be a grayish or an olive color. On top of their shell, there is an H-shaped depression. The eyes are held up by eye stalks on the top of the head, and behind them are horizontal depressions. The habitat of the Red-Jointed Fiddler Crab, is uncovered muddy or sandy beaches. Every crab digs his own hole and burrows into the ground. The burrow can range from 2-5 cm in diameter and can have various levels of depths. If the crab feels threatened, their burrow will be plugged with mud for safety. The Red-Jointed Fiddler Crab prefer areas of low salinity, and can survive in freshwater for only three weeks. They are usually found along the eastern shore of North America, ranging from Cape Cod to Texas. This crab will usually sit in sediment, and eat any of the nutrients found. Getting all their nutrients, they will leave behind little pellets of unusable sediment.

 

These crabs like to eat in puddles of water, so they can seperate nutrients from garbage. The fiddler crabs are omnivores. They'll eat algae and decaying vegetation. Sometimes, they'll even eat other fiddler crabs. But their main food source is cordgrass. Fiddler crabs reproduce every two weeks during the summer. During this time, the male fiddlers will make two burrows, a home, and a mating burrow. The male will burrow a small round hole, and when the females return from eating, they will stand at the edge of their burrow and try and attract a mate. If the female approves, she will go to the burrow, and the male will lead her back to his burrow. He then returns to his entrance and plugs it with mud. In the burrow, the mating will occur, and two weeks later the female will return to the surface and release her eggs into the ocean for development. Once a year old, the adult fiddler crabs will molt their shell. If during an attack, the male loses his large claw, the other claw will grow larger and then a new claw will grow to replace the missing one. These crabs breathe in oxygen, but however have gills that must remain wet to function. During the winter, these crabs will bury themselves to hibernate.

 

Author: Taighler R.

Published: 04/2008