Ctenopharyngodon idella

  • Scientific name

    • Ctenopharyngodon idella (Valenciennes, 1844)

  • Common name

    • Grass carp or White amur

  • Family

    • Cyprinidae

  • External links

    • Fishbase
Trait completeness 86%
Total data231
References40
Image of Ctenopharyngodon idella

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail

Egg (100.0%)

Trait id Trait Primary data Secondary Data References
1 Oocyte diameter 0.7-1.3 1.0 mm Horvath et al, 1992
1 Oocyte diameter 1.06-1.60 [Egg before swelling] 1.33 mm Mikodina and Makeyeva, 1981
1 Oocyte diameter 1.2-1.3 [Egg on ovulation] 1.25 mm Fishbase, 2006
1 Oocyte diameter 2.0-2.5 [Said when release] 2.25 mm Cudmore and Mandrak, 2004
1 Oocyte diameter 1.30-1.40 [Unfertilized eggs] 1.35 mm Khan et al, 2004
1 Oocyte diameter 1.3 [Mean diameter of mature, fully yolked, ovarian oocyte] 1.3 mm Olden et al, 2006
1 Oocyte diameter On ovulation, the egg is 1.2-1.3 in diameter 1.25 mm Shireman and Smith, 1983
2 Egg size after water-hardening 4.2-5 4.6 mm Bruslé and Quignard, 2001
2 Egg size after water-hardening 3.7-6 4.85 mm Horvath et al, 1992
2 Egg size after water-hardening 3.93-5.31 [Egg after swelling, the membrane diameter increases 3-5 times] 4.62 mm Mikodina and Makeyeva, 1981
2 Egg size after water-hardening 5-6 [After swelling] 5.5 mm Cudmore and Mandrak, 2004
2 Egg size after water-hardening 3.81 (3.27-4-.18) at 19 May & 4.09 (3.87-4.40) at 20 May 3.63 mm Kilambi and Zdinak, 1981
2 Egg size after water-hardening The eggs attain a maximum diameter of 4.32-5.32 in 1.5-2 hours after fertilization 4.82 mm Shireman and Smith, 1983
2 Egg size after water-hardening After the eggs have been fertilized and have absorbed water, the egg membrane expands to about 5-6 mm 5.5 mm Naca, 1989
3 Egg Buoyancy Pelagic, only water-hardened eggs floated Pelagic Lahnsteiner et al, 2001
3 Egg Buoyancy Pelagic Pelagic Bruslé and Quignard, 2001
3 Egg Buoyancy Pelagic Pelagic Le Houarn, 2001
3 Egg Buoyancy Drifting egg [The largest number of eggs are found in the upper water layer in the main river chanel] Pelagic Abdusamadov, 1986
3 Egg Buoyancy Eggs developp in pelagic water of the river current [The buoyancy of the egg is achieved by the penetration under the membrane of a considerable amount of water and the creation of perivitelline space] Pelagic Mikodina and Makeyeva, 1981
3 Egg Buoyancy Semi-buoyant [eggs may travel downstream 50 to 180 km] Pelagic Cudmore and Mandrak, 2004
3 Egg Buoyancy Develop in pelagic water Pelagic Kunz, 2004
3 Egg Buoyancy The eggs of chinese carps are semibuoyant and are carried by currents until they hatch Pelagic Scholfield, 2005
3 Egg Buoyancy Currents carry the eggs and larvae to the quiet water at the tributary mouth No category Brown and Coon, 1991
3 Egg Buoyancy Grass carp eggs are semi-buoyant and must be agitated or they will sink to the bottom and die Demersal Leslie et al, 1982
3 Egg Buoyancy Eggs and prolarvae drift more than 500 km dowstream in the Amur Pelagic Gorbach and Krykhtin, 1988
3 Egg Buoyancy The semi-buoyant eggs theoretically may drift from 50 to 180 km before hatching Pelagic Shireman and Smith, 1983
3 Egg Buoyancy Having a greater specific gravity than water, eggs sink to the bottom in still water; yet, they are semi-buoyant in a current, floating until the fry hatch Demersal Naca, 1989
4 Egg adhesiveness Slight stickiness, manifested only in the first 2-3 minutes in water Adhesive Mikodina and Makeyeva, 1981
4 Egg adhesiveness Not sticky Non-Adhesive Fishbase, 2006
4 Egg adhesiveness Non-adhesive Non-Adhesive Cudmore and Mandrak, 2004
4 Egg adhesiveness Characterized by slight stickiness (due to acid mucopolysaccharies on the surface of the envelope) observed only in the first 2-3 minutes Adhesive Kunz, 2004
4 Egg adhesiveness The outer layer has adhesive properties which dissapear during fertilization Adhesive Shireman and Smith, 1983
4 Egg adhesiveness The eggs are seperated and nonadhesive Non-Adhesive Naca, 1989
5 Incubation time 1-2 1.5 days Horvath et al, 1992
5 Incubation time 34-38 hours [24°] and 16-20 hours [28-30°C] 36.0 days Bruslé and Quignard, 2001
5 Incubation time 20-50 hourrs 35.0 days Le Houarn, 2001
5 Incubation time 34-36 hour [23-25°C], 50-70 h [18-20°C] 35.0 days Abdusamadov, 1986
5 Incubation time Hatched in 26-60 hours at 17-30°C, about 20-40 43.0 days Cudmore and Mandrak, 2004
5 Incubation time 20-24 hours 22.0 days Khan et al, 2004
5 Incubation time Hatching occurred within 48 h after fertilization [At 24.5°C] 48.0 days Kilambi and Zdinak, 1981
5 Incubation time 1.5 [Mean time to egg hatch within the range of average post-spawning the range post-spawning water temperatures] 1.5 days Olden et al, 2006
5 Incubation time Hatch between 18 and 30 hours at T>20°C, and developp normaly 18.0 days Scott and Crossma, 1973
5 Incubation time Lasts from 16 to 60 hours at temperatures ranging from 30 to 17°C 16.0 days Shireman and Smith, 1983
6 Temperature for incubation 23-25 [But also at lower T: 18-20] 24.0 °C Abdusamadov, 1986
6 Temperature for incubation At 19-23°C, the fertilization capacity of a considerable number of eggs was perserved slightly longer-up to 30 seconds] 21.0 °C Mikodina and Makeyeva, 1981
6 Temperature for incubation Between 17 and 26°C in natural conditions 17.0 °C Krykhtin and Gorbach, 1982
6 Temperature for incubation Optimal temperature is 21-26°C, with mortality increasing below 20°C 23.5 °C Cudmore and Mandrak, 2004
6 Temperature for incubation 24.5 [Reared conditions] 24.5 °C Kilambi and Zdinak, 1981
6 Temperature for incubation Above 20°C, developp normaly [Optimum 21-25°C] 23.0 °C Scott and Cross, 1973
6 Temperature for incubation The optimum temperature is between 25 and 27°C 25.0 °C Naca, 1989
6 Temperature for incubation The embryonic grass carp appears to be even more sensitive to cool conditions than the goldfish. High rates of deformity and poor survival at temperatures of 18.4°C or less using egg fertilized at 20°C. When fertilization was performed at 24.4°C, 5% survival of normal fry to 72 h occurred with incubation at 23.9°C but the few surviving fry at 20.9°C or less were all deformed. 18.4 °C Wiegand et al, 1988
7 Degree-days for incubation 24-50 37.0 °C * day Horvath et al, 1992
7 Degree-days for incubation 35-50 42.5 °C * day Abdusamadov, 1986
7 Degree-days for incubation 13 [Effective day-degrees] 13.0 °C * day Kamler, 2002
7 Degree-days for incubation 34-38 DD: 34-38 hours [24°] and 16-20 hours [28-30°C] 36.0 °C * day Bruslé and Quignard, 2001
7 Degree-days for incubation Hatched in 26-60 hours at 17-30°C, about 20-40 43.0 °C * day Cudmore and Mandrak, 2004
7 Degree-days for incubation Hatching occurred within 48 h after fertilization [At 24.5°C] 48.0 °C * day Kilambi and Zdinak, 1981
7 Degree-days for incubation Hatch between 18 and 30 hours at T>20°C, and developp normaly 18.0 °C * day Scott and Cross, 1973

Larvae (86.0%)

Trait id Trait Primary Data Secondary Data References
8 Initial larval size 5-5.2 5.1 mm Horvath et al, 1992
8 Initial larval size 5.2 5.2 mm Bruslé and Quignard, 2001
8 Initial larval size Mean 5.48, range 5.40-5.67 5.54 mm Kilambi and Zdinak, 1981
8 Initial larval size 5.0 5.0 mm Olden et al, 2006
8 Initial larval size The larvae captured (6.1-7.9 mm TL) ranged in age from 1 to 7 posthatching 7.0 mm Brown and Coon, 1991
8 Initial larval size Hatchlings measure 5.0-5.5 mm 5.25 mm Shireman and Smith, 1983
9 Larvae behaviour Pelagic and could derive Pelagic Bruslé and Quignard, 2001
9 Larvae behaviour The pelagic larvae then have a behavior of alternately sinkink and swimming giving them the potential for extensive downstream migration Pelagic Cudmore and Mandrake, 2004
9 Larvae behaviour Currents carry the eggs and larvae to the quiet water at the tributary mouth Demersal Brown and Coon, 1991
9 Larvae behaviour Eggs and prolarvae drift more than 500 km dowstream in the Amur Demersal Gorbach and Krykhtin, 1988
9 Larvae behaviour The pelagic larvae then have a behavior of alternately sinkink and swimming, which allows them to migrate farther downstream. Also: it lies on the bottom and occasionally swim vertically to the surface and drifts back to the bottom Demersal Shireman and Smith, 1983
11 Temperature during larval development 24.5 [Reared conditions] 24.5 °C Kilambi and Zdinak, 1981
11 Temperature during larval development During the grass carp experiments, water temperature averaged 27.7°C in the outdoor facilities and about 2°C lower in the indoor tanks [Also reared in other studies at 23-25°C; 21°C, 24°C and 28.1°C; final lethal temperature of 39.7°C] 24.0 °C Opuszynski et al, 1985
11 Temperature during larval development Water temperature at the time of capture ranged from 23 to 28°C 23.0 °C Brown and Coon, 1991
11 Temperature during larval development Reared at 25°C 25.0 °C Dabrowski, 1984
11 Temperature during larval development Fry and fingerlings in India tolerated a temperature range of 16-40°C 28.0 °C Shireman and Smith, 1983
11 Temperature during larval development Reared at 23-36°C 29.5 °C Wolnicki, 2005
11 Temperature during larval development The experiment was performed at a temperature of 24°C 24.0 °C Szlamiska, 1987
12 Sibling intracohort cannibalism Cannibalism is observed in juveniles Present Kozlowski and Poczyczynski, 1999
12 Sibling intracohort cannibalism No evidence of any form of aggression or cannibalism in silver carp, grasscarp Absent Hecht and Pienaar, 1993
13 Full yolk-sac resorption 7 days: the mesolarva measures 7.5 to 8.1 mm, has absorbed its yolk sac and feed exogenously 7.0 °C * day Shireman and Smith, 1983
14 Onset of exogeneous feeding 3 or 4 days after hatching larval grass begin carp feeding on rotifers and protozoans 3.0 °C * day Cudmore and Mandrak, 2004
14 Onset of exogeneous feeding 4.5 days: Feeding is mixed 4.5 °C * day Shireman and Smith, 1983
14 Onset of exogeneous feeding 7 days: the mesolarva measures 7.5 to 8.1 mm, has absorbed its yolk sac and feed exogenously 7.0 °C * day Shireman and Smith, 1983
14 Onset of exogeneous feeding Rearing fry and fingerlings involves nurturing 3-4 day-old postlarvae, which have begun to eat 3.5 °C * day Naca, 1989
14 Onset of exogeneous feeding These foods were first offered to the larvae 72 h after hatching 72.0 °C * day Rottmann et al, 1991

Female (83.0%)

Trait id Trait Primary Data Secondary Data References
15 Age at sexual maturity 5-7 6.0 year Horvath et al, 1992
15 Age at sexual maturity 4-5 4.5 year Bruslé and Quignard, 2001
15 Age at sexual maturity 5 [Sex not specified] 5.0 year Le Houarn, 2001
15 Age at sexual maturity 5.0 5.0 year Abdusamadov, 1986
15 Age at sexual maturity 1-2 [Malaysia] to 6-10 [Russia Fed, Germany], female specified 1.5 year Fishbase, 2006
15 Age at sexual maturity 2 to 4, up to 6-10 in their natural range, and 4-5 in the United States, and 1-8 in the introduced countries [Sex not specified] 8.0 year Cudmore and Mandrak, 2004
15 Age at sexual maturity 2-5 years in subtropical/tropical areas and 4-7 years in temperate regions [Sex not specified] 3.5 year Scholfield, 2005
15 Age at sexual maturity 4.5 [Both sex] 4.5 year Olden et al, 2006
15 Age at sexual maturity The grass carp investigated for fecundity were between 7+ and 15+ 7.0 year Gorbach, 1972
15 Age at sexual maturity Maturity occurs at ages from 1 to 11 years in females 1.0 year Shireman and Smith, 1983
16 Length at sexual maturity 40-100 70.0 cm Horvath et al, 1992
16 Length at sexual maturity 65 65.0 cm Abdusamadov, 1986
16 Length at sexual maturity 58.0-63.0 [Malaysia], and 73.8-79.2 [India], female specified 60.5 cm Fishbase, 2006
16 Length at sexual maturity 50-86 cm [Sex not specified] 68.0 cm Cudmore and Mandrak, 2004
16 Length at sexual maturity 65.0 [Both sex] 65.0 cm Olden et al, 2006
16 Length at sexual maturity The grass carp investigated for fecundity were between 66 and 96 cm 96.0 cm Gorbach, 1972
16 Length at sexual maturity 58-67 cm in females 62.5 cm Shireman and Smith, 1983
17 Weight at sexual maturity 3-10 6.5 kg Horvath et al, 1992
17 Weight at sexual maturity 5 [Sex not specifiec] 5.0 kg Le Houarn, 2001
17 Weight at sexual maturity 5.8 5.8 kg Abdusamadov, 1986
17 Weight at sexual maturity The grass carp investigated for fecundity were between 5,050 and 16,400 g in weight 5.0 kg Gorbach, 1972
17 Weight at sexual maturity For females: 4.76-7.03 [Cuttack], 5 [Israel], 2.3-3.2 |Malacca, Malaysia], 3.0-3.5 [Poland], 3+ [Taiwan] 5.89 kg Shireman and Smith, 1983
17 Weight at sexual maturity Average weight of 9.200 kg for fishes in the Changjiang River 9.2 kg Naca, 1989
18 Female sexual dimorphism Females may also develop deciduous tubercles, but thay are not as highly developped as in the males. Females exhibit soft, bulging abdomens and swollen, pinkish vents at onset of maturity Present Cudmore and Mandrak, 2004
18 Female sexual dimorphism Females also have pearl organs, although they are not as higlhy developed as in males. When fully ripe, females exhibit soft bulging abdomens ans swollen pinkish vents Present Shireman and Smith, 1983
18 Female sexual dimorphism The pectoral fins are thin and short, spreading out spontaneously like a fan. No pearl organs appear Absent Naca, 1989
19 Relative fecundity 40-80 60.0 thousand eggs/kg Horvath et al, 1992
19 Relative fecundity 120 120.0 thousand eggs/kg Le Houarn, 2001
19 Relative fecundity 80-105 92.5 thousand eggs/kg Khan et al, 2004
19 Relative fecundity The relative fecundity of the grass carp varies in the range 48-177 eggs, on average 110 eggs per g of body weight less the viscera 112.5 thousand eggs/kg Gorbach, 1972
19 Relative fecundity For cultured Indian specimens, average 82 eggs/g of total weight [Also: Relative fecundity varied from 48 to 177 with an average of 110 eggs per gram weight of the body less viscera] 82.0 thousand eggs/kg Shireman and Smith, 1983
19 Relative fecundity Average fecundity of 90.2 90.2 thousand eggs/kg Naca, 1989
20 Absolute fecundity 200-1500 850.0 thousand eggs Horvath et al, 1992
20 Absolute fecundity 100-900 500.0 thousand eggs Bruslé and Quignard, 2001
20 Absolute fecundity Mean of 765 [Range 210.500-1230.700] 720.6 thousand eggs Abdusamadov, 1986
20 Absolute fecundity The mean absolute fecundity over the entire period of the investigation (1963-1969) was approximatively 820 thousand eggs. The lowest fecundity (237 000) was recorded in a female of 7+, 67.5 cm long, and the highest (1687 000) in a female of 16+, 96 cm long. The bilk of the females (approximatively 90%) had a fecundity of from 600 to 1150 thousand eggs 1966.0 thousand eggs Gorbach, 1972
20 Absolute fecundity Range from 0.001 to 2 million eggs, but generally average 0.5 million for a 5 kg brrod stock, in the Amru basin, fecundity ranged from 0.2-1.7 million eggs with an average of 0.8 million 0.95 thousand eggs Cudmore and Mandrak, 2004
20 Absolute fecundity 225-2000 1112.5 thousand eggs Scholfield, 2005
20 Absolute fecundity Ranges from tens of thousands to two millions eggs with an average of 500 000 for 5 kg to 7 kg brood stock [Also: about 90% of the fish had from 600 000 to 1 150 000 eggs] 500.0 thousand eggs Shireman and Smith, 1983
20 Absolute fecundity Average 830,000 830.0 thousand eggs Naca, 1989
21 Oocyte development Asynchronous and synchronous development of oocytes was also noted. The oocyte development characteristics are determined by the conditions under which the fish are reared Asynchronous Gorbach, 1972
21 Oocyte development Many authors have noted asynchronous development of oocytes in females from China, the Tone River, Malaysia, the Amur River and the lower Volga River Asynchronous Shireman and Smith, 1983
22 Onset of oogenesis The gonads pass the winter in early maturity stages, develop to intermediate level during spring, and quickly reach final maturatrion just prior to spawning in June and July ['January', 'February', 'March', 'April', 'May', 'June', 'July'] Shireman and Smith, 1983
23 Intensifying oogenesis activity The gonads pass the winter in early maturity stages, develop to intermediate level during spring, and quickly reach final maturatrion just prior to spawning in June and July ['January', 'February', 'March', 'April', 'May', 'June', 'July'] Shireman and Smith, 1983
23 Intensifying oogenesis activity Vitellogenesis in these fishes completes in spring, when the maturation coefficients of females reaches maximum level ['April', 'May', 'June'] Makeeva et al, 1988
24 Maximum GSI value 18.4-21.6 % Prior to ovulation 20.0 percent Khan et al, 2004
24 Maximum GSI value 20% 20.0 percent Shireman and Smith, 1983
24 Maximum GSI value Average maturity rate of 14.2% 14.2 percent Naca, 1989

Male (67.0%)

Trait id Trait Primary Data Secondary Data References
27 Age at sexual maturity 4-6 5.0 years Horvath et al, 1992
27 Age at sexual maturity 3-4 3.5 years Bruslé and Quignard, 2001
27 Age at sexual maturity 5 [Sex not specifiec] 5.0 years Le Houarn, 2001
27 Age at sexual maturity 4.0 4.0 years Abdusamadov, 1986
27 Age at sexual maturity 1-2 [Malaysia] to 6.0-10.0 [Russian Fed], male specified 1.5 years Fishbase, 2006
27 Age at sexual maturity 2 to 4, up to 6-10 in their natural range, and 4-5 in the United States, and 1-8 in the introduced countries [Sex not specifed] 8.0 years Cudmore and Mandrak, 2004
27 Age at sexual maturity 2-5 years in subtropical/tropical areas and 4-7 years in temperate regions [Sex not specified] 3.5 years Scholfield, 2005
27 Age at sexual maturity 4.5 [Both sex] 4.5 years Olden et al, 2006
27 Age at sexual maturity Males mature an average of one year earlier 1.0 years Shireman and Smith, 1983
28 Length at sexual maturity 40-90 65.0 cm Horvath et al, 1992
28 Length at sexual maturity 63 63.0 cm Abdusamadov, 1986
28 Length at sexual maturity 51.0-60.0 [Malaysia], 60.-75.0 [Russia fed], male specified 55.5 cm Fishbase, 2006
28 Length at sexual maturity 65.0 [Both sex] 65.0 cm Olden et al, 2006
28 Length at sexual maturity Fish investigated were 76.0 ±1.2 cm 76.0 cm Belova, 1981
28 Length at sexual maturity 51-60 for males 55.5 cm Shireman and Smith, 1983
29 Weight at sexual maturity 3-7 5.0 kg Horvath et al, 1992
29 Weight at sexual maturity 5 [Sex not specifiec] 5.0 kg Le Houarn, 2001
29 Weight at sexual maturity 5.0 5.0 kg Abdusamadov, 1986
29 Weight at sexual maturity Most of the caught individuals weigthed 6-12 kg; this size is a characteristic of the sexually mature individuals 9.0 kg Ciolac, 2004
29 Weight at sexual maturity Fish investigated were 4920 ± 211 and 5342 ± 623 g 4920.0 kg Belova, 1981
29 Weight at sexual maturity For males: 4.54-6.61 [Cuttack, India], 0.95-1.40 [Cuttack, India], 4 [Israel], 2-3 [Malacca, Malaysia], 5.58 kg Shireman and Smith, 1983
30 Male sexual dimorphism Appereance of tubercles on the dorsal and medial surfaces of the pectoral fins in males Absent Cudmore and Mandrak, 2004
30 Male sexual dimorphism Males generally mature a year earlier than females Absent Scholfield, 2005
30 Male sexual dimorphism Extrnal sexual dimorphism appears in adults with the onset of maturity. Many authors have reported the presence of deciduous tubercles (pearl organs) on the dorsal and medial surfaces of the pectoral fins of male grass carp during the breeding season. Also found pearl organs on the dorsal fin and dorsum of the caudal peduncle Absent Shireman and Smith, 1983
30 Male sexual dimorphism The pectoral fin rays are thick and long, extending freely like sharp knives. In the reproduction season, pearl organs appear on the pectoral fins and opercula of mature male fish. They are coarse to the touch Absent Naca, 1989
32 Main spermatogenesis activity The relative gonad weight of mature males and females increase during spring, reach maxima just prior to spawning in June and July, then decrease progressively from august to October ['April', 'May', 'June', 'July', 'October'] Shireman and Smith, 1983
33 Maximum GSI value 2.27 [Not specified if the maximum and when ?] 2.27 percent Belova, 1981

Spawning conditions (93.0%)

Trait id Trait Primary Data Secondary Data References
36 Spawning migration distance About 125-260 km 192.5 km Abdusamadov, 1986
36 Spawning migration distance Very long migrations: thousands kms No data Krykhtin and Gorbach, 1982
36 Spawning migration distance Most of the reproducing white amur and silver carp complete a short post-spawning migration of some 100 km 100.0 km Gorbach and Kryhtin, 1988
37 Spawning migration period Spawning migration begins in mid-April at 15-17°C, the most intensive spawning migration is observed during 1-20 May ['April', 'May'] Abdusamadov, 1986
37 Spawning migration period In their native areas, grass carp begin migration to spawning areas when water temperatures reach 15-17°C No data Cudmore and Mandrak, 2004
37 Spawning migration period In May, there is an increasing amount of adults, probably as a result of the start of the crowding process that usually precedes the upstream migration. In June, the capture was the largest one; it signalises the peak of migration. The water temperature is of 19°C to 24°C ['May', 'June'] Ciolac, 2004
37 Spawning migration period Breeding migrations commence when water temperature reaches 15-17°C No data Shireman and Smith, 1983
39 Spawning season May-July ['May', 'July'] Horvath et al, 1992
39 Spawning season April until August ['April', 'May', 'June', 'July', 'August'] Bruslé and Quignard, 2001
39 Spawning season Spawning period continues from April to July [Mass spawning takes place at the end of May and in the beginning of June] ['April', 'May', 'June', 'July'] Abdusamadov, 1986
39 Spawning season Begins in June, extends into July and sometimes event the first days of August ['June', 'July', 'August'] Krykhtin and Gorbach, 1982
39 Spawning season All five accounts describe spawning as taking place in rivers during spring or early summer [Diverses sources: May-June in West River, China; Usually July, River Tone, Japan; July in Cho-shui Creek, Taiwan; Thought to be late Paril onwards, Amu-Darya River, Russia; June-July in Kuban River, Russia] ['April', 'May', 'June', 'July', 'August', 'September'] Scott and Cross, 1973
39 Spawning season The grass carp spawns earlier, at a lower temperature than silver carp and big head No data Ciolac, 2004
39 Spawning season White amur eggs are found in the beginning of June through the beginning of July ['June', 'July'] Gorbach and Krykhtin, 1988
39 Spawning season A well-marked and limited season characterizes grass carp spawning in temperature climates. The breeding season expands and becomes less distinct in tropical areas. Mature females occur in middle Amur River of the USSR from late may to early August with breeding peaks during late June and early July. The indigeneous Chinese populations spawn from late April to June in the Yangtzed River and from April to September in the Pearl and West River breed from the end of May to the middle of June. The naturalized population of the Tone River, Japan reproduces from June to August with peak activity from late June to mid-July ['April', 'May', 'June', 'July', 'August', 'September'] Shireman and Smith, 1983
39 Spawning season In the Changjiang River drainage, silver carp and grass carp generally starts spawning in late April or early May ['April', 'May'] Naca, 1989
40 Spawning period duration 6-8 [Spawning period continues from April to July [Mass spawning takes place at the end of May and in the beginning of June]] 7.0 weeks Abdusamadov, 1986
40 Spawning period duration 8-10 [Begins in June, extends into July and sometimes event the first days of August 9.0 weeks Krykhtin and Gorbach, 1982
40 Spawning period duration We captured larvae as early as 23 May and as late as 15 July; however, most of the larvae were taken within a 6-d period in late May [The long breeding season was evident in our samples] 23.0 weeks Brown and Coon, 1991
40 Spawning period duration White amur eggs are found in the beginning of June through the beginning of July No data Gorbach and Krykhtin, 1988
41 Spawning temperature 21-25 23.0 °C Horvath et al, 1992
41 Spawning temperature 20-25 22.5 °C Bruslé and Quignard, 2001
41 Spawning temperature 20-30 [Optimal temperature] 25.0 °C Le Houarn, 2001
41 Spawning temperature 18-20 19.0 °C Abdusamadov, 1986
41 Spawning temperature Begins above 17°C, 21-26 is assumed to be the optimal temperature for spawning 23.5 °C Krykhtin and Gorbach, 1982
41 Spawning temperature Optimum spawning temperature is generally thought to be between 20 and 22°C, but others reported water temperatures 26-30°C in China 28.0 °C Cudmore and Mandrak, 2004
41 Spawning temperature Between 17-26, with peak spawning at 21-26°C 21.5 °C Scholfield, 2005
41 Spawning temperature 19.2-29.0 24.1 °C Scholfield, 2005
41 Spawning temperature 19 [Temperature at which spawning is typically initiated] 19.0 °C Olden et al, 2006
41 Spawning temperature When water temperatures is at least 19°C or, more usually, four to five degrees higher [From 19-21 to 26-30] 20.0 °C Scott and Cross, 1973
41 Spawning temperature The water temperature stabilized for a relatively large period of time in the interval of 18°C to at least 22°C 18.0 °C Ciolac, 2004
41 Spawning temperature In the native range, reproduction occurs during the monsoon season, when water levels rise quickly, temperatures range between 20 and 30°C. A minimum temperature of 18°C has been reported for wuccessful spawning in most acclimatized populations 20.0 °C Shireman and Smith, 1983
41 Spawning temperature The optimum temperature for spawning is 22-28°C 25.0 °C Naca, 1989
42 Spawning water type Slow current, sides of river Flowing or turbulent water Bruslé and Quignard, 2001
42 Spawning water type Water with current Flowing or turbulent water Billard, 1997
42 Spawning water type Water with current Flowing or turbulent water Le Houarn, 2001
42 Spawning water type Spawning takes place after a sharp rise in the water level and current velocity Flowing or turbulent water Abdusamadov, 1986
42 Spawning water type Flowing water Flowing or turbulent water Mikodina and Makeyeva, 1981
42 Spawning water type Places with a rapid and turbulent water current, about 0.7-1.4 m/s Flowing or turbulent water Krykhtin and Gorbach, 1982
42 Spawning water type Riverbeds with strong current Flowing or turbulent water Fishbase, 2006
42 Spawning water type Primary channels of rivers and canals during high water, upper part of the water column over rapids and sand bars, preferred spawning habitat is found in turbid, turbulent water at the confluence of rivers or below dams, prefer to spawn in water currents ranging from 0.6 and 1.5 m/s, but will spawn in current as low as 0.2 m/s, or even in ponds where current is absent [Increases in water level exceeding 122 cm within 12 hour period are required for spawning] Stagnant water Cudmore and Mandrak, 2004
42 Spawning water type Spawning grounds are usually located in river reaches characterized by turbulent or whirlpool-like flow, often in the vicinity of islands or stream junctions [Reported current velocities of spawning areas in China ranged from 0.33 to0.90m/s] Flowing or turbulent water Scholfield, 2005
42 Spawning water type In a water current of between 0.5-2.4 m/sec Flowing or turbulent water Scott and Cross, 1973
42 Spawning water type Adults spawn upstream in the tributaries [high current velocities and long segments of unimpounded river] Flowing or turbulent water Brown and Coon, 1991
42 Spawning water type The existence and the persistence of the increasing water level, the water flow up to 3 m per second No category Ciolac, 2004
42 Spawning water type Apparent minimum current velocity of 0.6 m/second to keep eggs supported in the water column Flowing or turbulent water Leslie et al, 1982
42 Spawning water type Spawn in the primary channels of rivers and canals. [In relatively-large rivers] Stagnant water Shireman and Smith, 1983
43 Spawning depth Shalllow waters No data Bruslé and Quignard, 2001
43 Spawning depth Shallow waters: tens of centimeters to 2 m of waters 2.0 m Krykhtin and Gorbach, 1982
44 Spawning substrate Pelagophilous Pelagophils Mikodina and Makeyeva, 1980
44 Spawning substrate Gravel bottomed areas Lithophils Fishbase, 2006
44 Spawning substrate Their eggs are deposited in flowing water and develop in palegic water Pelagophils Kunz, 2004
44 Spawning substrate The silver carp an the grass carp seem to prefer the superficial waters as well as the big head stay in the deeper horizons of the water Phytophils Ciolac, 2004
44 Spawning substrate Pelagophilic spawner Pelagophils Shireman and Smith, 1983
44 Spawning substrate The eggs are fertilized in the water Pelagophils Naca, 1989
45 Spawning site preparation No, open waters/substratum egg scatterers Open water/substratum scatter Fishbase, 2006
45 Spawning site preparation Not any male spawning territory No category Ah-King et al, 2004
46 Nycthemeral period of oviposition Occurs in the morning and evening during calm weather Day Krykhtin and Gorbach, 1982
46 Nycthemeral period of oviposition Spawning of Tone river population occurs from early morning to early evening at dawn and twilight. In induced breeding, spawninfg was observed at all times of day with peak taking place at night. Also other demonstrated the possibility of nocturnal spawning in nature Day Shireman and Smith, 1983
47 Mating system During the spawning process, each female is usually by two or more males No category Cudmore and Mandrak, 2004
47 Mating system Group, communal spawning: females usually followed by more than two males, swim against the current for a considerable distance and then spawn Promiscuity Ah-King et al, 2004
47 Mating system Mating is promiscuous. Two to three males follow the female Promiscuity Shireman and Smith, 1983
48 Spawning release Multiple spawning Multiple Bruslé and Quignard, 2001
48 Spawning release One clear seasonal peak per year Total Fishbase, 2006
48 Spawning release Either single spawning per year or two or four spawnings per year Total Vila-Gispert and Moreno-Amich, 2002
48 Spawning release Multiple spawning in a year has been reported, but probably rarely occurs Multiple Cudmore and Mandrak, 2004
48 Spawning release Intermittent spawner in the Amur basin. When the absolute fecundity of 90 females was depicted the curve was clearly two-peaked for 82 females (91%) and had one perka for only eigth females (9%); the latter females should be classified as fish which lay all their eggs on a single occassion. The size of the first batch of eggs in females in which the sizes of yolk ooctyes had a two-peaked curve ranged from 55 to 91.5% and was on average 67% of absolute fecundity Multiple Gorbach, 1972
48 Spawning release Presents the only evidence for multiple-spawning by individual grass carp in one year Multiple Shireman and Smith, 1983
49 Parity Live between 5-11, and up to 15 years No category Cudmore and Mandrak, 2004
49 Parity Shortly adter spawning, some white amur enter marshy ponds for feeding. In the fall when the water level begins to drp, they return to the Amur channel where they over-winter seperately from juveniles Iteroparous Gorbach and Kryhtin, 1988
50 Parental care Non guarders No care Fishbase, 2006
50 Parental care None No care Ah-King et al, 2004