The eel has an upper-body that is yellow, a black line down the middle and the lower-body is usually a mix of white and brown. Along the backbone of the eel, the dorsal fin is preceded by numerous isolated small spines that can be raised, giving them the name. The dorsal fin also has many prominent eyespots along the base. There are many different variations of the Spiny Eel. They can grow up to be 14 inches long, but are usually smaller.