[Articoli Scientifici] Channa orientalis

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Tratto da: Snakeheads (Pisces, Channidae): A Biological Synopsis and Risk Assessment
 Di Walter R. Courtenay,James David Williams


Reprinted with permission from Rohan Pethiyagoda from Pethiyagoda, R. 1991. Freshwater fishes of Sri Lanka. Wildlife Heritage Trust of Sri Lanka, Colombo, Sri Lanka.

After Munro, 1955; female

Original description: Channa orientalis Schneider, in Bloch and Schneider, 1801:496, pl. 90. M.E. Blochii, Systema Ichthyologiae iconibus cx illustratum. Post obitum auctoris opus inchoatum absoluit, correxit, interpolavit Jo.Gottlob Schneider, saxo. Sumtibut Austoris Impressum et Bigliopolio Sanderiano Commissum, Beroloni. i-lx + 1-584, pls. 1-110. Type locality: “Habitat in India orientale” (=east India). No types known (Paepke, 1993). Paepke (1993) noted that Schneider’s description was based on an illustration in Gronovius (1763).

Synonyms: There has been much confusion regarding the taxonomy of the Ceylon snakehead. Many have considered this species to be part of what we term the Channa gachua complex as reflected in the following synonymy, all of which are synonyms of C. gachua and are invalid for C. orientalis (Ralf Britz, personal commun., 2003).
                   Ophiocephalus auranticus Hamilton, 1822:69, 368, pl. 23, fig. 22.
                   Ophicephalus marginatus Cuvier, 1829:230, fide Menon, 1999:275.
                   Ophicephalus coramota Cuvier, 1831:414, fide Menon, 1999:275.
                   Ophicephalus fuscus Cuvier, 1831:414, fide Menon, 1999:275.
                   Ophicephalus limbatus Cuvier, 1831, no p., pl. 201, fide Menon, 1999:275.
                   Ophicephalus marginatus Cuvier, 1831, no p., pl. 201, fide Menon, 1999:275.
                   Ophicephalus montanus McClelland & Griffith, 1842:583, fide Menon, 1999:275.
                   Philypnoides surakartensis Bleeker, 1849:19, fide Menon, 1999:275.
                   Ophiocephalus apus Canestrini, 1861:77, pl. 4, fig. 7.
                   Ophiocephalus kelaartii Gunther, 1861:472, fide Talwar and Jhingran,
                           1991:1019, and Menon, 1999:275.
                   (?)Channa burmanica Chaudhuri, 1919:284, pl. 22, fig. 4.
                   Ophiocephalus gachua kelaarti Gunther: Munro, 1955:100.
                   Note: Although Channa burmanica is listed as a synonym, some authors
                           recognize this species as valid (Peter Ng, personal commun., in Vierke,
                           1991b; Ralf Britz, personal commun., 2003).

Common names: Ceylon snakehead; Asiatic snakehead; smooth breasted snakehead (Munro, 1955; Pethiyagoda, 1991); green snakehead (Ettrich, 1989); kola kanaya (Pethiyagoda, 1991).


         Native range: Channa orientalis is endemic to southwestern Sri Lanka (Pethiyagoda, 1991; Ralf Britz, personal commun., 2003), specifically to the “wet zone” and “lower south western hills” (Pethiyagoda, 1991). Mendis (1954) included both C. orientalis and Ophicephalus gachua from Sri Lanka, commenting that the former may or may not possess pelvic fins. The Ceylon snakehead, however, lacks pelvic fins (Deraniyagala, 1929; Pethiyagoda, 1991; Ralf Britz, personal commun., 2003). Talwar and Jhingran (1992) noted that C. orientalis lacking pelvic fins occurs in Sri Lanka, Myanmar, and Java; nevertheless, reports of this fish from Myanmar and Java refer to members of the C. gachua complex. DeWitt (1960) considered absence of pelvic fins in snakeheads as an anomalous character; this conclusion, however, is not supported by C. orientalis or other snakeheads that lack pelvics (C. asiatica, C. bleheri, C. burmanica, apparently some members of the C. gachua complex, and C. nox).

         Munro (1955) correctly identified the snakehead species lacking pelvic fins in Sri Lanka as Channa orientalis and treated the taxon with pelvics as C. gachua kelaarti. Lim and others (1990) noted  that Myers and Shapovalov (1932) synonymized C. gachua with C. orientalis, but suggested these species are separate with the latter lacking pelvic fins. Because C. orientalis is endemic to Sri Lanka, records from southern India and elsewhere are erroneous.

         Introduced range: No introductions known, although its presence in the Greater Sunda Islands (Kottelat, 1985) would represent an introduction if the species is indeed Channa orientalis. More than likely, however, Kottelats (1985) reference is to a species of the C. gachua complex. Pethiyagoda (1991) noted a possible introduction in the Mahaweli basin of Sri Lanka.

         Size: Sometimes cited as the smallest species of snakehead (Ismail, 1989; Talwar and Jhingran, 1992), a comment often also used for Channa gachua. Pethiyagoda (1991) noted that this snakehead typically does not exceed 10 cm and, therefore, is significantly smaller than C. gachua.

         Habitat preference: Deraniyagala (1929) and Munro (1955) cited “clean freshwater pools close to streams” as the preferred habitat. Pethiyagoda (1991) stated that it occurs in “shaded, clear, flowing water with a silt or gravel substrate” and “shallow rivulets barely deeper than its own body.” He also predicted pollution and destruction of rainforest habitat in Sri Lanka would likely negatively affect populations of this species.

         Temperature range: No specific information found. Because the species is endemic to Sri Lanka (unlikely), it is strictly tropical.

         Reproductive habits: Ettrich (1989) reported this species as a mouthbrooder. He described the basic body color as brown, remarking that the flanks of males sometimes are dove gray with a violet cast, becoming paler ventrally. The dorsal and caudal fins of males are “sky-blue,” black and orange, with a blue anal fin margined in black and white with black rays, and the eye red. Reproductively active females change from brown to shades of blue. During spawning, the male wraps itself around the female near the surface, after which the male broods the eggs in its oral cavity, typically remaining in an upper corner of an aquarium. Fry remain in the male parents mouth until able to survive on their own. Females sometimes retrieve stray fry into their oral cavities, returning the young to the parental care of the male. Fry are never ejected via the mouth but rather leave via the gill openings. This is somewhat similar to behavior observed in Channa bleheri (Vierke, 1991b). Both parents provide parental care with the female defending territory. It is unknown if the Ceylon snakehead is a mouthbrooder only in aquaria (Ettrich, 1989).

         Ettrich (1989) assumed that there were two forms of Channa orientalis in Sri Lanka, one with and one without pelvic fins, but remarked that there were no hybrids known between these forms. The one with pelvic fins, however, is part of the C. gachua complex (Deraniyagala, 1929; Pethiyagoda, 1991; Ralf Britz, personal commun., 2003).

         Feeding habits: Moyle and Senanayake (1984) determined that most gut contents consisted of terrestrial insects, the remainder comprised of trichopterans and a few fishes. Pethiyagoda (1991) noted that in aquaria, chopped steak is readily accepted by this snakehead.

         Characters: Gular part of head without patch of scales. Pelvic fins absent. Predorsal scales 6-7; scales from posterior border of orbit to posterior edge of preopercle 5-6. Lateral line scales 36-42. Anal fin rays 20-22; dorsal fin rays 30-34. Pectoral fins with 13-15 rays. Ocellated spot at posterior end of dorsal fin, above caudal peduncle, in juveniles and females. Lower jaw with 10-20 canines behind single row of villiform teeth, the latter expanding to about 7 rows at jaw symphysis; prevomer and palatines with caninelike teeth.

         Commercial importance in the United States: Sometimes listed on aquarist-oriented websites, but often misidentified.

         Commercial importance in native range: Pethiyagoda (1991) stated, “Small numbers are used by the aquarium fish export trade.”

         Environmental concerns: Perhaps a thrust predator like other snakeheads. Because this species is endemic to Sri Lanka, its ability to establish in North America, if introduced, would be limited to subtropical areas (extreme southern Florida, Hawaii) or warm thermal springs.