The Arao Tidal Flat is home to a creature called the anajako (Japanese mud shrimp.) It is a relative of the hermit crab but resembles a mantis shrimp. About 10 centimeters in length, it digs Y-shaped burrows 1 to 2 meters deep in the tidal flat. In Arao, they are referred to as majaku.

The method for catching anajako is unique. A brush is inserted into the burrow, and when the anajako, mistaking the brush for an intruder, leaves the burrow to push it out, it is captured. This traditional Ariake Sea fishing method is called shaku-tsuri (brush fishing). This fishing method is practiced from June to September.

Mud shrimps can be eaten whole, shell and all, after being cooked. Recommended ways to enjoy this delicacy include deep-fried, as tempura, boiled in salted water, and stewed.