鮎 (siluroid)
1. 【鮎魚】 - A type of fish with a large head, wide mouth, and a round and short tail. Its skin is slimy and lacks scales. The back is dark blue-black, and the belly is white. The fish has four whiskers on its upper and lower jaws. It rests in the mud during the day and is active at night, feeding on small fish, shellfish, and frogs.
2. 鮎魚 (siluroid) - Belongs to the suborder Siluroidea, characterized by a large head and flattened tail, with a slimy skin and no scales. For example, "鮎魚上竹" means "the siluroid is slippery and hard to catch on bamboo", metaphorically indicating that progress is difficult.