The Giant Mottled Eel is one of the largest species of eels in the world and is the most widely distributed species of anguillid eel.
The species can be distinguished from other anguillid eels by its mottled colouration, arrangement of teeth and the long dorsal fin, which begins closer to the gill opening than to the anus. The teeth in both jaws are arranged in two or three rows. One row consists of distinctly enlarged teeth that often form a cutting edge. The inner row comprises smaller teeth that are usually separated from the cutting row by a narrow toothless groove.
It is found in warm freshwater habitats including small oceanic islands from the western Indian Ocean across the Indo-Pacific to French Polynesia, and as far north as southern Japan.
The Giant Mottled Eel is known to have multiple spawning populations. One of its largest populations lives in the areas adjacent to the western North Pacific (e.g. northern Indonesia, Philippines, Taiwan, Japan) and has an offshore spawning area in the same oceanic region of the North Equatorial Current as the Japanese eel, Anguilla japonica.
- Kuroki, M., J. Aoyama, M. J. Miller, T. Yoshinaga, S. Shinoda, S. Hagihara, and K. Tsukamoto. 2009. Sympatric spawning of Anguilla marmorata and Anguilla japonica in the western North Pacific Ocean. Journal of Fish Biology 74: 1853–1865.
- Watanabe, S., M. J. Miller, J. Aoyama, and K. Tsukamoto. 2009. Morphological evaluation of the population structure of Anguilla marmorata across its range. Journal of Fish Biology 74: 2069–2093.
- Minegishi Y., J. Aoyama, and K. Tsukamoto. 2008. Multiple population structure of the giant mottled eel Anguilla marmorata. Molecular Ecology 17: 3109–312.
- Smith, D.J. Anguillidae. Freshwater eels. in Carpenter, K.E. & V.H. Niem (ed) The Living Marine Resources of the Western Central Pacific. Vol. 3. FAO species identification guide for Fishery purposes. FAO. Pp. 2068.