Without it, the reef looks bare. The Long-Handed masking crab is a decorator. It attaches pieces of sponge, algae, and debris to its carapace. It becomes invisible. Predators swim past. Prey does not flee. The crab is a ghost. Habitat is complex reef. It needs structures to climb and materials to cut. Sponges are preferred. They are soft and easy to attach. The crab uses hooked setae on its shell to hold the decorations. Found throughout the North Island and northern South Island. It is common in the Poor Knights Islands. The marine reserve there provides ideal conditions. The crab thrives where fishing is banned. Diet includes the very sponges it wears. It eats small invertebrates living on the sponge. It is a gardener and a grazer. It maintains its disguise by feeding on it. The cycle is closed. Threats include collection. Aquarium traders value its appearance. Removal from the wild reduces local populations. Habitat damage from anchors also affects it. The crab is fragile. It breaks easily.