The scientific name of the flathead fish is climbing rock loach. The body is long and disc-shaped, the front is flat, the body width is larger than the body height, and the caudal peduncle is slightly flattened. The even fins are wide and spreading, and the beginning of the pectoral fins is located below the posterior edge of the nostrils, with the end over the beginning of the ventral fins. Ventral fin attached to sucker, conspicuously covering anus, with well-developed fleshy flap at base; anal fin small, with stiff spines. Caudal peduncle taller than caudal peduncle long. Caudal fin obliquely truncated.

Specialized in size, it inhabits fast-flowing, gravelly mountain streams and rivers, and lives attached to rocks.

The secret of its ability to climb rocks is that its broad pectoral and abdominal fins and soft abdomen form an effective "suction cup" that keeps it safe from rapids and allows it to climb steep riverbeds, but they can only crawl on smooth, wet rocks.

What a flathead looks like:/i?ct=503316480&z=0&tn=baiduimagedetail&word=%C5%C0%D1%D2%F6%FA&in=6&cl=2&cm=1&sc=0& lm=-1&pn=5&rn=1

Climbing rock loach

Open classifications: Fish, Vertebrates, Marine fishes, Animals

Beaufortia evertfi (Nichols et Pope )

Flat-finned loach family

Body long and discoidal, flattened in front, body wider than high, caudal peduncle slightly laterally compressed. The mouth is slightly broad, arcuate. Anastomosing folds divided into 3 leaves, with 2 pairs of minute anastomosing whiskers between the leaves. Oral antennal whiskers 1 pair. Lower lip "figure of eight" shaped, notched in the middle, with papillae on the edge of the labial segments. Gill pores small, ending above pectoral fins. Even fins broad, spreading, starting point of pectoral fins below posterior margin of nostrils, ending over starting point of ventral fins: ventral fins attached to sucker, conspicuously over anus, with well-developed fleshy flap at base; anal fins small, with stiff spines. Caudal peduncle taller than caudal peduncle long. Caudal fin obliquely truncated.

Benthic small fish. Specialized in size, inhabiting fast-flowing, gravelly mountain streams and rivers, adsorbing on rocks.

Distributed in various water systems on Hainan Island.