Latin name

Gymnothorax undulatus

Other names

Gymnothorax undulatus

Identification

The body is elongated, without scales. The body height is 14-17 times the total body length. The vertebrae are 126-138.

Features of fish fins

The dorsal fin begins anterior to the gill openings, extends to the caudal part of the body, and joins the caudal and anal fins. Dorsal spines (total): 0; Dorsal soft rays (total): 0; Anal spines: 0; Anal soft rays: 0. 

Fish colouring

The body is dark brown to greenish brown. The body and fins are covered with a wavy pattern of numerous closely spaced whitish spots that form irregular stripes. There are small dark spots between the lighter spots. The head is greenish yellow, with the corner of the mouth darker in some individuals.

Distribution

Widespread in tropical Indo-Pacific waters from East Africa, the Persian Gulf, and the Red Sea to the islands of French Polynesia and Hawaii; northward to the Ryukyu and Bonin Islands, south to Australia. Eastern Pacific: Costa Rica, Panama.

Habitat

Marine benthic fish. They live on the outer slopes of coral reefs, among rocks and stones, as well as in lagoons at depths from 9 to 110 meters.  

Size

The maximum length is 150 cm. The maximum recorded body mass of individuals caught off the coast of Taiwan is 1343 g.

Behavior

They are nocturnal. 

Food and feeding habits

They feed on fish, squid and crustaceans. 

Reproduction

The reproductive process begins with egg deposition. This usually occurs in shallow water where the females swim to after leaving their usual shelters. Later, males swim to the clutch site and fertilize the eggs. A clutch may be fertilized by several males.

Fishing

This species is of no interest to commercial fisheries.

Relationship with a person

Aggressive, may bite if threatened. Used in Chinese medicine. This species is only suitable for large aquariums (public aquariums or zoos).