noted that a closely related species,
C. nox, that has very similar markings to
C. asiatica, is available for sale in live-food fish markets in Ghangzhou, raising the possibility that
O. miliaris might be a synonym of that species. Resolution of this situation is complicated because there are apparently no types of
O. miliaris.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT]Common names: Chinese snakehead; chi hsing y (Yangtze River basin, China); hua-t’sai-yu (Tungting Lake on Chang Jiang [Yangtze] River); ktal (Japan; Uyeno and Akai, 1984; Hosoya, 2002).
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[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Native range: China, middle and lower Chang Jiang (Yangtze) basin, and Xun River basin in Guangxi and Guangdong provinces (Kimura, 1934; Pearl River Fisheries Research Institute, 1991). Also reported from Hainan Island, China (Kimura, 1934) where it is likely native rather than introduced.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Introduced range: Taiwan (Musikasinthorn, 2000); Japan, Ishigaki Shima Island in the Ryukyu Islands (Uyeno and Akai, 1984; Hosoya, 2002). Klee (1963) reported that this species was “occasionally found in Florida waters,” but we have found no evidence that it is established.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Size: Up to 34 cm (Daiqin and others, 1999). By studying annual ring development on scales, they noted a linear relationship between scale length and body length for this species. They also commented that growth is rapid during the first 2 years of life and slows thereafter. They recommended regulating a minimal harvestable age of this species at 2.6 years for resource conservation purposes.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Habitat preference: No information available. Probably a riverine species.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Temperature range: No information available. Nevertheless, distribution within native range (32-22[SIZE=-1]o[/SIZE] N) indicates a warm temperate to subtropical species.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Reproductive habits: No information found concerning reproduction in natural habitats. Hosoya (2002) stated this species does not build a nest but provides parental care in Japan where the species was introduced. Breder and Rosen (1966) summarized this species, in aquaria, as producing floating eggs, the eggs about the “size as that of the head of a pin.” Reproductively active females become paler with a pink cast, with dark brown markings becoming darker and silver markings becoming brighter. Reproductively active males also become darker. The prespawning female rises to the surface of an aquarium, gulps air, and rolls from side to side. The male then rises, circles the female, and they embrace, rising to the surface with the male squeezing the female. They are reported to have rolled once, then sank, releasing themselves, repeating the sequence after a few minutes. In aquaria, spawning can occur every 6 to 10 days. Reproductive activities appear to occur at night. Hatching in aquaria occurs in about 24 hours at 28 [SIZE=-1]o[/SIZE]C. There are some indications that the male may be a mouthbrooder. Both male and female are reported to aggressively protect against anything introduced into an aquarium when eggs or fry are present.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Feeding habits: No information found, but likely a thrust predator.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Characters: Gular region of head without patch of scales. Pelvic fins absent. Dorsal fin with 44 rays; anal fin 26 rays; pectoral fin 14 rays. Lateral line scales 57; predorsal scales 12; rows of scales between dorsal origin and lateral line 5; scale rows between lateral line and midline of belly 16. Color pattern distinct among snakeheads with dark chevrons on sides and large ocellus centered on caudal peduncle. The center of the ocellus is not round but more quadrangular in shape (Bureau of Aquatic Products Industry, 1988; Lee and Ng, 1991), unlike that illustrated in Pearl River Fisheries Research Institute (1991). The most closely related snakehead is Channa nox, which has 47-51 dorsal fin rays, 31-33 anal fin rays, and is black on the upper half of the body. Like C. asiatica, C. nox also lacks pelvic fins and has a large black ocellus on the caudal peduncle.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Commercial importance in the United States: Ross B. Socolof (personal commun., 2003) reported Channa asiatica as the first snakehead to have been imported to the contiguous United States for the aquarium fish trade. Subsequent accounts of this species in the aquarium fish literature (Innes, 1920, 1955; Armstrong, 1923; Stoye, 1935; Axelrod and Schultz, 1955) are indicative of its availability through much of the early to mid-1900s. Typically not listed on aquarist-oriented websites.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Commercial importance in native range: Nichols (1943) commented that it was never seen for sale in China. Nevertheless, it is sold in the aquarium fish trade outside its native range in Singapore (Ng and Lim, 1990). Daiqin and others (1999) recommended restricting the legal harvestable age to 2.6 years, a clear indication that the species is being fished commercially in China. Ping Zhuang (personal commun., 2002) noted that this species is now common in aquaculture in China.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Environmental concerns: Probably a thrust predator on other fishes and invertebrates like many other snakeheads. According to Ross B. Socolof (personal commun., 2003), this was the first snakehead imported into the U.S. for the aquarium fish trade, the earliest imports occurring in the late 1800s or early 1900s.
[FONT=Arial,Helvetica,Geneva,Sans-serif,sans-serif][/FONT] Comments: The diploid number of chromosomes of Channa asiatica is 46 (Wu and others, 1986).
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