Appearance and lifestyle:
The giant spotted hermit crab (Dardanus megistos) is easy to spot – with three sets of legs and a vivid orange body decorated with ringed white spots, these crabs certainly are uniquely designed!
The crab’s first set of legs features claws, one larger than the other, which are used for defence. When threatened, the crab can seal itself tightly inside its shell, creating a "one-crab security system". The second and third sets are covered in comb-like rows of red and brown bristles, giving the crab a look that says, “I might be small, but I’m stylish!”– the crab uses these legs for walking along the seafloor. To top it off, the rear of the body is specially adapted to fold into the shell, offering extra protection – a portable panic room for a crab on the go.
Giant hermit crabs aren’t just visually striking; they also have a lot of character. Sometimes, they’re boldly preening in front of scuba divers, completely unfazed by their presence. However, they’ll often scurry for cover, dragging their shells behind them in a rather comedic fashion.
As these crabs grow, they require a bigger living space. So, they face the challenge of finding larger shells, which are often in short supply. This struggle intensifies during moulting, as their exoskeletons become soft and vulnerable to predators. The urgency to find a larger shell can lead to fights between crabs. In some cases, larger crabs may even pull smaller, weaker ones out of their shells using their claws, creating a dramatic battle for a new home.
Habitat:
Found in tropical reef environments, they inhabit both littoral and subtidal zones, ranging from intertidal areas to depths of 50 meters—proving they’re truly “claw-some” survivors!
Diet:
These omnivorous crabs are scavengers, feasting on small invertebrates like worms and molluscs.
Threats:
Some of the threats faced by giant spotted hermit crabs are pollution, limited shell availability, climate change etc.
A giant hermit crab switching homes!