The Bandit Coral Crab, Tetralia nigrolineata, has a compact body with a carapace width of 1 to 2 centimeters (0.4 to 0.8 inches). Its creamy white or pale yellow body is marked by bold, black longitudinal stripes across its back, a pattern to which both its common name and scientific name refer; nigrolineata translates to "black-lined." The legs and pincers are typically banded with similar dark stripes, providing distinct identification among other coral crabs.
This species lives within intricate coral reef systems, commonly inhabiting the branches of branching corals, particularly Acropora species, at depths typically ranging from 1 to 25 meters (3 to 80 feet). It maintains a symbiotic relationship with its coral host, cleaning the coral by removing sediments and detritus that could otherwise smother polyps. In return, the coral provides shelter and protection from predators. Primarily nocturnal, the Bandit Coral Crab becomes more active at night to forage for small invertebrates and detritus. During the day, it typically remains hidden within coral branches, using its striped coloration as camouflage. Like many marine crabs, T. nigrolineata has a planktonic larval stage that disperses through the water column before settling and metamorphosing into juvenile crabs, which then seek out suitable coral habitats to establish their adult lives.
- creamy white or pale yellow body
- bold black longitudinal stripes across back
- dark banded legs and pincers
