Leather Jacket/竹仔鱼

Leatherjacket fish are marine fish known for their tough, sandpaper-like skin and a prominent, retractable, serrated spine on their heads. They have highly compressed, firm bodies, often with mottled brownish or greenish colors. They are generally found in inshore, coastal, or reef environments globally. They have small mouths with beak-like teeth used for eating crustaceans, mollusks, and algae. Their skin is famously thick and leathery, leading to the name "leatherjacket," and it is often covered in tiny, fine, scale-like spinules.