Brachyura is a term used in zoology to refer to a group of decapod crustaceans, commonly known as crabs. The name "brachyura" originates from the Greek words "brachys," meaning short, and "oura," meaning tail, which alludes to the characteristic feature of these creatures; they possess a short and broad abdomen that is folded beneath the cephalothorax, giving them a distinctive appearance.
Crabs are characterized by their flat, wide bodies, which are covered by a hard exoskeleton. They have two pairs of antennae, with the second pair being significantly shorter than the first. The front pair of pincers, known as chelipeds, are used for defense, capturing prey, or as tools for various activities. Brachyuran crabs exhibit a wide range of sizes, from a few millimeters to large species measuring over 12 feet across.
These diversely adapted crustaceans inhabit various aquatic environments, including marine, freshwater, and terrestrial ecosystems. They are well-known for their ability to walk sideways, a unique locomotion style exclusive to crabs. Brachyuran crabs have a diverse diet, feeding on algae, mollusks, small fish, detritus, and even carrion.
Due to their ecological significance and economic value as food sources, brachyuran crabs have been extensively studied and have a significant impact on human societies. They play essential roles in maintaining ecological balance, such as controlling populations of other organisms and serving as a food source for larger predators. Moreover, they have become popular subjects of scientific research for their intriguing biology, diverse adaptations, and evolutionary history.
