Brachyura spp.

15cm
0-100m
17398 sites
Various
Crabs, belonging to the Brachyura family, are a common and captivating sight for divers and snorkellers. With their sideways scuttling and often colourful carapaces, they add a touch of intrigue to any underwater encounter. Typically around 15cm in size, these crustaceans can be found in a wide range of habitats, from shallow reefs to deeper waters down to 100m. Divers often spot them hiding amongst rocks, coral, or even buried in the sand, always on the lookout for a tasty morsel. While their diet varies depending on the species, many crabs are opportunistic scavengers, helping to keep the reef clean. Spotting a crab is always a fun experience, and seeing them in their natural habitat provides a glimpse into the diverse world of marine life. While crabs may not be the most charismatic megafauna, their presence is a sign of a healthy ecosystem. Keep an eye out for their unique behaviours, from their defensive postures to their intricate feeding techniques. While they are categorized as 'Not Evaluated' by conservation standards, every observation helps build a picture of their population and health. With a diver appeal score of 2/5, they might not be the main attraction, but crabs certainly add a special something to the underwater world.
Crabs are easily identified by their broad, flattened bodies and ten legs, the first pair of which are modified into pincers (claws). Their sideways walking is a distinctive trait. Colouration varies greatly between species, from drab browns and greens to vibrant reds, oranges, and blues. Look for the shape of the carapace (the main body shell) as different species have different shapes, sometimes almost circular, others more rectangular or oval. Behaviourally, their tendency to hide under rocks or in crevices is a key identifier.
1761 sites