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Ctenopharyngodon idella (Valenciennes, 1844) Grass carp |
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| Grass carp, White amur | ||
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photo by
Ramani Shirantha |
| Family: | Xenocyprididae (East Asian minnows) | |||
| Max. size: | 150 cm TL (male/unsexed); max.weight: 45 kg; max. reported age: 21 years | |||
| Environment: | benthopelagic; freshwater; brackish; depth range 0 - 30 m, potamodromous | |||
| Distribution: | Asia: Eastern China and Russia (Ref. 48) in eastern Siberia, Amur River system (Ref. 1441). Widely transported around the world (Ref. 7248). Persists only in Europe by stocking (Ref. 59043). Introductions often brought with it the parasitic tapeworm Bothriocephalus opsarichthydis (synonym of B. acheilognathi) (Ref. 12217). Several countries report adverse ecological impact after introduction. | |||
| Diagnosis: |
Dorsal spines (total): 0-0; Dorsal soft rays (total): 10-11; Anal spines: 0-0; Anal soft rays: 10-14. Diagnosis: No barbels; snout very short, its length less than or equal to eye diameter; postorbital length more than half head length (Ref. 4967). 18 soft rays for caudal fin (Ref. 40476). Diagnosed from rather similar species Mylopharyngodon piceus by having the following characters: body olive to brassy green above, silvery white to yellow below; body cylindrical; pharyngeal teeth laterally compressed, serrated, with a groove along grinding surface, usually in two rows, 2,5-4,2 (Ref. 59043). Description: Body sub-cylindrical (Ref. 52193). Head pointed; mouth terminal; eyes nearer tip of snout than hind margin of head, lateral in position (Ref. 52193). Dorsal fin with 3 unbranched and 7-8 branched rays; anal fin with 3 unbranched and 8 branched rays; dorsal fin short, midway between tip of snout and end of caudal peduncle, origin slightly in front of pelvic fins (Ref. 52193). Scales in lateral line 37-42; 16 scales around caudal peduncle (Ref. 52193). Colouration: Body silvery, head and fins dark grey (Ref. 52193). |
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| Biology: | Adults occur in lakes, ponds, pools and backwaters of large rivers (Ref. 5723), preferring large, slow-flowing or standing water bodies with vegetation (Ref. 52193). Tolerant of a wide range of temperatures from 0° to 38°C, and salinities to as much as 10 ppt and oxygen levels down to 0.5 ppm (Ref. 52193). It feeds on higher aquatic plants and submerged grasses; takes also detritus, insects and other invertebrates. One of the world's most important aquaculture species and also used for weed control in rivers, fish ponds and reservoirs (Ref. 9987). Spawn on riverbeds with very strong current (Ref. 30578). Utilized also fresh and eaten steamed, pan-fried, broiled and baked (Ref. 9987). Considered as a pest in most countries because of the damages made to submerged vegetation (Ref. 43281). | |||
| IUCN Red List Status: | Least Concern (LC); Date assessed: 30 March 2020 Ref. (130435) | |||
| Threat to humans: | potential pest | |||
| Country info: | Introduced to Arkansas and made numerous interstate stockings that quickly spread into 35-40 states (Ref. 10294). Has been reported to occur in 45 states where it competes for food with invertebrates (e.g. crayfish) and other species, causes significant changes in macrophyte, phytoplankton and invertebrate communities, interferes with the reproduction of other fishes, decreases available refugia for other fishes, and so on (Ref. 45864). A popular fish sold in live fish markets. Found in 3 out of 6 live fish markets near the Lakes Erie and Ontario (Ref. 53249). Uncommon but its population is increasing in the lower Mississippi River. Found in lakes, ponds, pools, and backwaters of large rivers. Introduced to control aquatic weed problems in lakes and ponds. Its introduction has been proven to be more costly than beneficial as many fishes, waterfowl and other native species depend on aquatic vegetation (Ref. 86798). Also Ref. 1739. | |||