Identification: Snakeheads (family Channidae) are morphologically similar to the North American native Bowfin (Amia calva), and the two are often misidentified. Snakeheads can be distinguished from Bowfin by the position of pelvic fins (directly behind pectoral fins in snakeheads, farther back on body in Bowfin) and the size of the anal fin (elongate and similar in size to dorsal fin in snakeheads, short and much smaller than dorsal fin in Bowfin). Additionally, Bowfin can be identified by the presence of a bony plate between the lower jaws (gular plate) and a distinctive method of swimming through undulation of the dorsal fin.
Blotched Snakehead is very similar to Northern Snakehead Channa argus, with slight differences in coloration: C. argus has an irregular blotch-like dark marking on the caudal peduncle, whereas C. maculata generally has a complete bar-like dark mark preceded by pale bar-like areas. Additional morpholgical differences include:
| || C. argus || C. maculata |
| Lateral line scales || 60-67 || 41-60 |
| Transverse scales below lateral line || 12-13 || 11 |
| Dorsal fin rays || 49-50 || 40-46 |
| Anal fin rays || 31-32 || 26-30 |
Morphological data summarized from Courtenay and Williams (2004).
Means of Introduction: This species of snakehead was stocked as a food fish in Hawaii. Cobb (1902) stated that the China-fish or "Ophicephalus" was brought to Hawaii from China by the Chinese. However, Jordan and Evermann (1905) suggested that the species had been introduced into Hawaii from Borneo. Devick (1991b) indicated it was a deliberate introduction for use as a food fish (he listed the period of introduction as both 1800 and the 19th century). Jordan and Evermann (1902, 1905) reported that "China-fish" (along with goldfish) were generally sold alive to the Chinese [in Hawaii]. Borneo was mentioned as source by Jordan and Evermann (1902).
Unknown means in other areas. The most likely mechanism is as a released food fish, as it is common in the food trade and rarely available in the aquarium trade (Courtenay and Williams 2004).
References: (click for full references)
Axelrod, H. R., W. E. Burgess, N. Pronek, and J. G. Walls. 1985. Dr. Axelrod's atlas of freshwater aquarium fishes. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Brock, V.E. 1960. The introduction of aquatic animals into Hawaiian waters. International Revue der Gesamten Hydrobiologie 45(4):463-480.
Cobb, J.N. 1902. Commercial fisheries of the Hawaiian Islands. Pages 381-499 in Report of the Commissioner for the year ending June 30, 1901. U.S. Commission of Fish and Fisheries, Government Printing Office, Washington, DC.
Courtenay, W.R., Jr., and J.D. Williams. 2004. Snakeheads (Pisces: Channidae): A biological synopsis and risk assessment. Circular 1251, US Geological Survey, Gainesville, FL. 143 pp.
Courtenay, W.R., Jr., J.D. Williams, R. Britz, M.N. Yamamoto, and P.V. Loiselle. 2004. Identity of introduced snakeheads (Pisces, Channidae) in Hawai'i and Madagascar, with comments on ecological concerns. Bishop Museum Occassional Papers 77:1-13.
Devick, W.S. 1991a. Disturbances and fluctuations in the Wahiawa Reservoir ecosystem. Project F-14-R-15, Job 4, Study I. Division of Aquatic Resources, Hawaii Department of Land and Natural Resources.
Devick, W.S. 1991b. Patterns of introductions of aquatic organisms to Hawaiian freshwater habitats. 189-213 in New directions in research, management and conservation of Hawaiian freshwater stream ecosystems. Proceedings of the 1990 symposium on freshwater stream biology and fisheries management, Division of Aquatic Resources, Hawaii Department of Land and Natural Resources.
Froese, R. and D. Pauly (eds). 2012. FishBase. World Wide Web electronic publication. Available from: http://www.fishbase.org. Version (08/2012).
Jordan, D.S., and B.W. Evermann. 1902. Preliminary report on an investigation of the fishes and fisheries of the Hawaiian Islands. Pages 353-380 in Report of the United States Commissioner of Fish and Fisheries for the year ending June 30, 1901. U.S. Commission of Fish and Fisheries, Government Printing Office. Washington, DC.
Jordan, D.S., and B.W. Evermann. 1905. The aquatic resources of the Hawaiian Islands. Part I. The shore fishes. Bulletin of the U.S. Fish Commission 23:1-574.
Kottelat, M., A.J. Whitten, S.N. Kartikasari, and S. Wirjoatmodjo. 1993. Freshwater fishes of Western Indonesia and Sulawesi. Periplus Editions, Ltd., Republic of Indonesia.
Maciolek, J.A. 1984. Exotic fishes in Hawaii and other islands of Oceania. Pages 131-161 in W.R. Courtenay, Jr., and J.R. Stauffer, Jr., eds. Distribution, biology, and management of exotic fishes. The Johns Hopkins University Press, Baltimore, MD.
Okada, Y., 1960. Studies of the freshwater fishes of Japan, II, Special part: Prefectural University of Mie. Journal of the Faculty of Fisheries 4(3): 1-860.
Roberts, T.R. 1989. The freshwater fishes of Western Borneo (Kalimantan Barat, Indonesia). Memoirs of the California Academy of Science 14. California Academy of Sciences, San Francisco, CA. 210 pp.
Smith, H.M. 1945. The fresh-water fishes of Siam, or Thailand. Bulletin of the U.S. National Museum (Smithsonian Institution) 188:1-622.
Talwar, P.K., and A.G. Jhingran, editors. 1992. Inland fishes of India and adjacent countries. A.A. Balkema, Rotterdam, The Netherlands.
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.