Oncorhynchus mykiss

  • Scientific name

    • Oncorhynchus mykiss (Walbaum, 1792)

  • Common name

    • Rainbow trout

  • Family

    • Salmonidae

  • External links

    • Fishbase
Trait completeness 96%
Total data257
References85
Image of Oncorhynchus mykiss

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail

Egg (100.0%)

Trait id Trait Primary data Secondary Data References
1 Oocyte diameter 4.6-6.2 [3-5] 5.4 mm Internet, 2005
1 Oocyte diameter 3-5 4.0 mm Mellinger, 2002
1 Oocyte diameter 3-5 4.0 mm Barton, 1996
1 Oocyte diameter 3.5-5 4.25 mm Bruslé and Quignard, 2001
1 Oocyte diameter 4.7 ± 0.2 4.7 mm Whitehead et al, 1978
1 Oocyte diameter 3-5 4.0 mm Fishbase, 2006
1 Oocyte diameter 4.5 4.5 mm Tyler and Sumpter, 1996
1 Oocyte diameter 5.0 [Final egg diameter] 5.0 mm Tyler and Sumpter, 1996
1 Oocyte diameter 3-5 4.0 mm Scott and Crossman, 1973
1 Oocyte diameter 4.0 [Mean diameter of mature, fully yolked, ovarian oocyte] 4.0 mm Olden et al, 2006
1 Oocyte diameter 5.0 ± 0.2 [For controls] 5.0 mm Bromage et al, 1984
1 Oocyte diameter Between 4.3 and 5.0 for different batches of fish under different conditions 4.3 mm Davies and Bromage, 2002
1 Oocyte diameter Different means range from 4.09 to 4.35 [Ova diameter] 4.09 mm Springate et al, 1984
1 Oocyte diameter 5.4 at ovualtion 5.4 mm Tyler et al, 1990
1 Oocyte diameter Range: 4.53-5.90, mean 5.15 5.21 mm Purtscher and Humpesch, 2006
2 Egg size after water-hardening 4-4.2 [n = 1633] 4.1 mm Escaffre and Bergot, 1985
2 Egg size after water-hardening 4.9 ± 0.38, n=75 [Eggs stripped from mature females, fertilized and incubated in water: hydrated eggs] 4.9 mm Bonislawska et al, 2001
2 Egg size after water-hardening Mean of 3.72 ± 0.29 for 2 year old fish and 5.02 ± 0.29 for 3 year old fish 3.72 mm Springate nad Bromage, 1985
2 Egg size after water-hardening Mean of 3.91 ± 0.1 [For females aged 2], 5.08 ± 0.3 [For females age 3] and 5.74 ± 0.16 [For females age 4] 3.91 mm Kato and Kamler, 1983
2 Egg size after water-hardening 5.9 [Fully hardened eggs] 5.9 mm Penaz, 1981
2 Egg size after water-hardening Egg diameter for controls was around 5.25 (based on Fig. 3) 5.25 mm Contreras-Snachez et al, 1998
2 Egg size after water-hardening Diameter of egg in the day of hatching ranged from 5.26 to 5.54 5.26 mm Winnicki et al, 1970
3 Egg Buoyancy Demersal Demersal Internet, 2005
3 Egg Buoyancy Demersal Demersal Tyler and Sumpter, 1996
3 Egg Buoyancy Demersal Demersal Scott and Crossman, 1973
3 Egg Buoyancy The eggs of Salmonidae are buried in unguarded nests called 'redds' and are demersal-nonadheive Demersal Kunz, 2004
3 Egg Buoyancy Sink deeply into crevices Demersal Greeley, 1932
4 Egg adhesiveness None, adhesive during water hardening process Adhesive Internet, 2005
4 Egg adhesiveness The eggs of Salmonidae are buried in unguarded nests called 'redds' and are demersal-nonadheive Non-Adhesive Kunz, 2004
4 Egg adhesiveness Salmonidae, whose eggs are not sticky Non-Adhesive Woynarovich, 1962
5 Incubation time 28-49 38.5 days Groot, 1996
5 Incubation time 4-7 weeks 5.5 days Fishbase, 2006
5 Incubation time 4-7 weeks 5.5 days Scott and Crossman, 1973
5 Incubation time About 8 weeks 8.0 days Coad, 2006
5 Incubation time 103.5 [3.9°C] and 19 [15°C] 103.5 days Kerr and Grant, 1999
5 Incubation time 70.7 [5°C], 47.2 [7.5°C], 32.9 [10°C] and 24.8 [12.5°C] for 50% hatch for steelhead 70.7 days Jensen, 1997
5 Incubation time 87.2 [5°C], 56.2 [7.5°C], 38.7 [10°C] and 27.9 [12.5°C] for 50% hatch for rainbow trout 87.2 days Jensen, 1997
5 Incubation time 25.0 [Mean time to egg hatch within the range of average post-spawning the range post-spawning water temperatures] 25.0 days Olden et al, 2006
5 Incubation time Estimates of the number of days required for 50% of egg to hatch: 73 [5°C], 33 [10°C], and 21 [15°C] [In different populations: 63 [At 4-13.0°C], 29-48 [At 3.4-18.9°C], 63 [At 3.1-15.4°C], 36-50[At 3-15°C], 26-31 [At 9-14°C]] 8.5 days Humpesch, 1985
5 Incubation time 101 [3.23°C], 45 [7.2°C], 29.6 [10°C], 18 [15.5°C] 101.0 days Embody, 1934
5 Incubation time For female age 3: mean was 38, range 34-41 [At 9°C], 32, range 28-36 [At 10°C], 26, range 23-29 [at 12°C] and 22, range 20-23 [At 14°C] 37.5 days Kamler and Kato, 1983
5 Incubation time At 6°C, hatching occurs after 81 days 6.0 days Ninness et al, 2006
5 Incubation time Rainbow trout embryo test organisms and control ones began to hatch 34 days after the start of fertilization. The control embryos hatched in 7-8 days 7.5 days Stasiunaite and Kazlauskiene, 2002
5 Incubation time Egg development from fertilization to 50% hatch at various constant temperatures: 111 days [At 3°C], 51.9 days [At 6°C], 41 days [At 8°C], 34 days [At 10°C], 18 days [At 17.5°C] 50.0 days Velsen,1987
5 Incubation time Time to 50% hatch in controls was 29 days 50.0 days Brauner and Wood, 2002
5 Incubation time Rainbow trout hatch after approximately 22 days at 13°C 22.0 days Gibb et al, 2007
5 Incubation time Hatching time was consistent between batches of embryos: 30-34 days postfertilization (at 10°C) 32.0 days Ninness et al, 2006
6 Temperature for incubation 7-12 [3.9-9.4] 9.5 °C Barton, 1996
6 Temperature for incubation 7-12 = optimal temperature [Regimes of rising temperatures] 9.5 °C Groot, 1996
6 Temperature for incubation Low water temperature (<13°C) is considered for good quality 13.0 °C Fishbase, 2006
6 Temperature for incubation Optimal 6, range 3-9 6.0 °C Saat and Veersalu, 1996
6 Temperature for incubation Optimum is about 10°C [21.0°C is the upper lethal temperature for embryo development] 10.0 °C Kerr and Grant, 1999
6 Temperature for incubation 7°C 7.0 °C Wojtczak et al, 2004
6 Temperature for incubation 5-12.5 8.75 °C Jensen, 1997
6 Temperature for incubation Water temperature tested were 14 ± 0.5 and 10 ± 0.5°C 14.0 °C Nagler et al, 2000
6 Temperature for incubation Optimum temperature was between >7 and 11°C [The lower limit for hatching ca 3°C and the upper limit was between ca. 16 and 20°C] 7.0 °C Humpesch, 1985
6 Temperature for incubation There were no significant differences in eyeing or to swim-up among the four strains at an incubation temperature of 7 or 4°C. However, at 2°C there was significantly lower survival among all four strains 7.0 °C Stonecypher et al, 1994
6 Temperature for incubation Incubate at 10°C 10.0 °C Springate nad Bromage, 1985
6 Temperature for incubation Water temperature was not controlled and rose gradually between 5 and 10°C 5.0 °C Craik and Harvey, 1984
6 Temperature for incubation Incubation temperature set at 10°C 10.0 °C Billard and Gillet, ???
6 Temperature for incubation 9 ±0.1°C 9.0 °C Kato and Kamler, 1983
6 Temperature for incubation Cultured in cages in flowing water at four temperatures: 9±0.1°C (natural temperature of spring water feeding this hatchery), 10, 12 and 14°C 9.0 °C Kamler and Kato, 1983
6 Temperature for incubation Egg mortality during incubation from fertilization to 50% hatch at various temperatures: 18% [At 3.0°C], 4.0% [At 6°C], 22% [At 10°C], 93.0% [At 16°C] 50.0 °C Velsen,1987
6 Temperature for incubation Eggs of each female were incubated at a constant water temperature of 10°C in compartmentalized verticalflow incubation traysand kept seperated from other batches of eggs 10.0 °C Contreras-Snachez et al, 1998
6 Temperature for incubation Water tem perature was maintained at 12.2 +/- 0.1°C over the duration of the study 12.2 °C Brauner and Wood, 2002
6 Temperature for incubation All variants were incubated in duplicate in small baskets placed in a vertical incubator with flow-through water at 9-14°C 11.5 °C Babiak and Dabrowski, 2003
6 Temperature for incubation Water temperature in incubators was maintained at 11.5°C, range ± 1.5°C 11.5 °C Lizardo-Daudt and Kennedy, 2008
6 Temperature for incubation Recirculated fresh water at 12 ± 1°C 12.0 °C Gibb et al, 2007
6 Temperature for incubation The constant water temperature of 10 ± 1°C was maintained 10.0 °C Perkowski and Formicki, 1997
6 Temperature for incubation 10°C 10.0 °C Ninness et al, 2006
7 Degree-days for incubation 323 323.0 °C * day Barton, 1996
7 Degree-days for incubation 290-340 315.0 °C * day Bruslé and Quignard, 2001
7 Degree-days for incubation 309.8-354 [Between 5-12.5°C] for steelhead and 348.4-436.0 [Between 5-12.5°] for rainbow trout 331.9 °C * day Jensen, 1997
7 Degree-days for incubation 310 310.0 °C * day Bascinar and Okumus, 2004
7 Degree-days for incubation 330 [i.e. 33 days at 10°C at ca. optimum temperature] 330.0 °C * day Humpesch, 1985
7 Degree-days for incubation 283-288 [Effective day-degrees] 285.5 °C * day Kamler, 2002
7 Degree-days for incubation For female age 3: mean was 346 [At 9°C], 320 [At 10°C], 312 [at 12°C] and 308 [At 14°C] 3.0 °C * day Kamler and Kato, 1983
7 Degree-days for incubation Hatching was recorded from 273°D (first day of observed hatched larvae) until 328°D (when all embryos were hatched) 273.0 °C * day Lizardo-Daudt and Kennedy, 2008
2 Egg size after water-hardening 4.17-4.42 4.29 mm Momin and Devrim, 2018
2 Egg size after water-hardening 4.2–6.3 4.2 mm Liberoff et al, 2019
2 Egg size after water-hardening 3.36-5.63 4.5 mm Springate and Bromage, 1985
2 Egg size after water-hardening 4.5 4.5 mm Tyler et al, 1996
3 Egg Buoyancy demersal Demersal Mellinger, 1994
3 Egg Buoyancy demersal Demersal Saint-Dizier and Chastant-Maillard, 2014
3 Egg Buoyancy negatively buoyant Pelagic Weitkamp, 2008
6 Temperature for incubation 9.12 9.12 °C Pankhurst et al, 1996
7 Degree-days for incubation 300.0 300.0 °C * day Weeks Santos et al, 2019

Larvae (100.0%)

Trait id Trait Primary Data Secondary Data References
8 Initial larval size 14-15.5 14.75 mm Internet, 2005
8 Initial larval size 12.8 12.8 mm Olden et al, 2006
8 Initial larval size Range: 10.00-14.00, mean 11.73 12.0 mm Purtscher and Humpesch, 2006
9 Larvae behaviour Fry remain in the gravel for about 2 to 3 weeks after hatching before emerging from the gravel at night Demersal Groot, 1996
9 Larvae behaviour Immediate move downward into the gravel [prior to dispersal the alevins exhibt both horizaontal and vertical movements within the gravel] Demersal Kerr and Grant, 1999
9 Larvae behaviour Swim-up from fertilization: 500 degree-days [From hatching 500 less 310] Pelagic Bascinar and Okumus, 2004
10 Reaction to light Newly hatched alevin have a very strong negative response to light [emergence coincides with a sudden shift from photonegative to a higly photopositve state] Photophobic Kerr and Grant, 1999
10 Reaction to light The free-embryos of the gravel spawning Oncorhynchus are negatively phototactic in the beginning and hide in the interstitial. After the onset of exogeneous feeding, the young fish become positively phototactic and emerge from the substrate Photophobic Bohlen, 2000
10 Reaction to light Oncorhynchus mykiss yolk-sac alevins exhibit a strong negative photoresponse during their under gravel residency, which switches rapidly towards a positive one at the time of emergence Photopositive Jatteau and Bardonnet, 2008
11 Temperature during larval development Preferred temperature is about 13°C, the upper lethal temperature about 24°C 13.0 °C Scott and Crossman, 1973
11 Temperature during larval development 4° to <13°C [optimal 7-10°C] in nursery streams, 14.7° preferred by fingerling trout 8.5 °C Kerr and Grant, 1999
11 Temperature during larval development It is relevant to note that a temperature of at least 7-8°C is reported as being necessary for initial feeding of Atlantic salmon and rainbow trout 7.5 °C Wallace and Aasjord, 1984
11 Temperature during larval development The alevins were reared in a cold dark roomat 11-12°C 11.5 °C Stasiunaite, 2003
12 Sibling intracohort cannibalism Present Present Hecht and Pienaar, 1993
12 Sibling intracohort cannibalism Newly hatched rainbow trout are sometimes cannibalized by juveniles of the same species Absent Kerr and Grant, 1999
12 Sibling intracohort cannibalism The most numerous of the possible egg eaters seen around rainbow trout redds were juvenile of six to eight inches Absent Greeley, 1932
13 Full yolk-sac resorption 3-7 days to absorb the yolk 5.0 °C * day Scott and Crossman, 1973
13 Full yolk-sac resorption 190 [Swim-up from fertilization: 500 degree-days, from hatching 500 less 310] 190.0 °C * day Bascinar and Okumus, 2004
13 Full yolk-sac resorption For female age 3 (prior to yolk sac resorption no food was administered to larvae): 540 DD [At 10°C], 336 [At 12°C], 262 DD [At 14°C] 3.0 °C * day Kamler and Kato, 1983
13 Full yolk-sac resorption In the control, yolk utilisation ended after 20 days of exposure, but it was resorbed 3-5 days later in the test alevins, 11-12°C 4.0 °C * day Stasiunaite, 2003
14 Onset of exogeneous feeding 500 500.0 °C * day Bruslé and Quignard, 2001
14 Onset of exogeneous feeding The fry commence feeding about 15 days after hatching 15.0 °C * day Scott and Crossman, 1973
14 Onset of exogeneous feeding Young fish were expected to feed 60 days post-fertilization at 10°C 60.0 °C * day Springate and Bromage, 1985
8 Initial larval size 111-290 200.5 mm Marchetti and Nevitt, 2003
12 Sibling intracohort cannibalism Present Present Musseau et al, 2017
13 Full yolk-sac resorption 20-31 days 25.5 °C * day Goldchinfar et al, 2011

Female (83.0%)

Trait id Trait Primary Data Secondary Data References
15 Age at sexual maturity 3-5 or 6-8 4.0 year Barton, 1996
15 Age at sexual maturity 3 3.0 year Groot, 1996
15 Age at sexual maturity 2 [Sex not specified] 2.0 year Bruslé and Quignard, 2001
15 Age at sexual maturity 3 [Female] 3.0 year Fishbase, 2006
15 Age at sexual maturity Usually 3-5, to as late as 6 years 4.0 year Scott and Crossman, 1973
15 Age at sexual maturity 2.5 [Both sex] 2.5 year Olden et al, 2006
15 Age at sexual maturity Females sampled were between 2-4 3.0 year Kato and Kamler, 1983
16 Length at sexual maturity 30.5-45.7 or 50.8-76.2 38.1 cm Barton, 1996
16 Length at sexual maturity 15 [Both sex] 15.0 cm Olden et al, 2006
16 Length at sexual maturity Females sampled were 37.1 ± 0.8 [Age 2], 56.0 ± 3.7 [Age 3] and 60.5 ± 2.6 [Age 4] 37.1 cm Kato and Kamler, 1983
17 Weight at sexual maturity Females sampled were 826 ± 75 g [Age 2], 33220 ± 854 [Age 3] and 4015 ± 694 [Age 4] 826.0 kg Kato and Kamler, 1983
19 Relative fecundity 1.676 ± 276 up to 2.531 ± 453 1.68 thousand eggs/kg Dubois and Plaster, 1989
19 Relative fecundity 1.5-2 1.75 thousand eggs/kg Bruslé and Quignard, 2001
19 Relative fecundity 2.0 2.0 thousand eggs/kg Whitehead et al, 1978
19 Relative fecundity 2.370 ± 0.089 [Controls] 2.37 thousand eggs/kg Bromage et al, 1984
19 Relative fecundity From 1.791 ± 0.1 to 2.69 ± 0.169 [For different groups under different conditions] 1.79 thousand eggs/kg Davies and Bromage, 2002
19 Relative fecundity At ovulation 2.629 ± 231 2.63 thousand eggs/kg Tyler et al, 1990
19 Relative fecundity The relative feucndity for control was about 2.4 (based on Fig. 2) 2.4 thousand eggs/kg Contreras-Snachez et al, 1998
20 Absolute fecundity 0.2-12 6.1 thousand eggs Internet, 2005
20 Absolute fecundity 4.1-4.4 4.25 thousand eggs Barton, 1996
20 Absolute fecundity 0.2-12.7 [generally from 0.5-3.2, average =2] 6.45 thousand eggs Groot, 1996
20 Absolute fecundity 2.844 ± 713 up to 6.239 ±1.236 2.84 thousand eggs Dubois and Plaster, 1989
20 Absolute fecundity 0.7-4 2.35 thousand eggs Fishbase, 2006
20 Absolute fecundity Up to 12.749 12.75 thousand eggs Coad, 2006
20 Absolute fecundity From 5.381 ± 0.3 to 5.63 ± 0.251 [For different groups under different conditions] 5.38 thousand eggs Davies and Bromage, 2002
20 Absolute fecundity 2000-3000 2500.0 thousand eggs Tyler et al, 1990
20 Absolute fecundity The mean number of eggs produced by females: early stress: 2967 +/- 182; late stress 2533 +/-124; whole-period stress= 2734 +/-149; controls= 2593 +/-132 2967.0 thousand eggs Contreras-Snachez et al, 1998
21 Oocyte development Group-synchronous Group-synchronous Frantzen et al, 1997
21 Oocyte development Group-synchronous Group-synchronous Rinchard, 1996
21 Oocyte development Synchronous ovarian organization, determinate fecundity Synchronous Fishbase, 2006
21 Oocyte development Group-synchronous spawner Group-synchronous Tyler et al, 1990
22 Onset of oogenesis May ['May'] Bon et al, 1999
22 Onset of oogenesis June-July ['June', 'July'] Billard and Breton, 1977
22 Onset of oogenesis September ['September'] Tyler et al, 1990
23 Intensifying oogenesis activity GSI rose sharply from Mid-September to Mid-November = the rapid development phase [From up 6% to 15.3 ± 0.6%] ['September', 'October', 'November'] Bon et al, 1999
23 Intensifying oogenesis activity September-October ['September', 'October'] Billard and Breton, 1977
23 Intensifying oogenesis activity Based on GSI graph, mainly in November, but a slight increase then in February [The rate of increase in oocyte size was maximal between September and late November], with an ovulation in February ['February', 'September', 'November'] Tyler et al, 1990
24 Maximum GSI value 16.5 ± 0.5 [November to late November] 16.5 percent Bon et al, 1999
24 Maximum GSI value 20% just prior to ovulation in February 20.0 percent Tyler et al, 1990
24 Maximum GSI value 10.5 ± 1 [Age 2]; 10.7 ± 1.7 [Age 3] and 16.5 ± 1.9 [Age 4] for females sampled 10.5 percent Kato and Kamler, 1983
24 Maximum GSI value Mean of 14.9 (range 14?5-15.3) for anadromous populations, mean of 14.6 (range 8.3-22.6) for resident populations 10.15 percent Fleming, 1998
24 Maximum GSI value The mean GSI : early stress = 20.9 +/- 0.8; late stress = 19.9 +/- 0.6; whole-period stress = 21.4 +/- 0.9; controls = 19.8 +/- 0.8 20.9 percent Contreras-Snachez et al, 1998
26 Resting period 1 [December] 1.0 months Bon et al, 1999
26 Resting period 0.5 ± 0.07 [GSI remains at a minimum from December to May= very slow ovarian development phase] 7.0 months Bon et al, 1999

Male (100.0%)

Trait id Trait Primary Data Secondary Data References
27 Age at sexual maturity 2 [Sex not specified] 2.0 years Bruslé and Quignard, 2001
27 Age at sexual maturity 2-3 [Male] 2.5 years Fishbase, 2006
27 Age at sexual maturity As early as 1 year by males (rarely), the usual age would be 3-5, with males often maturing a year younger than females 4.0 years Scott and Crossman, 1973
27 Age at sexual maturity 2.5 [Both sex] 2.5 years Olden et al, 2006
28 Length at sexual maturity 15 [Both sex] 15.0 cm Olden et al, 2006
30 Male sexual dimorphism No nuptial tubercles but minor changes to head, mouth, and color especially in spawning males Absent Scott and Crossman, 1973
30 Male sexual dimorphism Breeding males have an elongated snout, the lower jaw is hooked and the roof of the mouth is white Present Coad, 2006
30 Male sexual dimorphism In Salmo, most Salvelinus, and most Oncorhynchus, a major sexual difference is found in the development , in normal breeding individuals, of elongated, hooked jaws with enlarged teeth.An upturned lower jaw is technically called a kype; an enlarged and often distorted upper jaw is termed a snout.Kype and sount development differs not only among individuals but also among species and conspecific populations: it is generally greater in stream-dwelling and anadromous forms than in lake-spawning or strickly freshwater forms.Kypes andsnouts are best developed in males, although females of some species also develop smaller ones. Another secondarytrait is a hump anterior to dorsal fin, found especially in males. Present Willson, 1997
30 Male sexual dimorphism Males are bigger than females Absent Fleming, 1998
31 Onset of spermatogenesis August, September ['August', 'September'] Ya-yi et al, 2001
32 Main spermatogenesis activity 2 No data Groot, 1996
32 Main spermatogenesis activity September-October ['September', 'October'] Ya-yi et al, 2001
33 Maximum GSI value 10 10.0 percent Suquet et al, 1994
33 Maximum GSI value Peaked in October 5.4 ± 0.8, then declined in November 5.4 percent Ya-yi et al, 2001
33 Maximum GSI value Mean of 5 for resident population 5.0 percent Fleming, 1998
34 Spermatogenesis duration 2 2.0 months Escaffre et Billard. Cahiers du Laboratoire de Montereau N°3 (Novembre 1976) 43-46
34 Spermatogenesis duration Spermiation began in October and lested until January [Lowest Gsi in June and July] 5.0 months Ya-yi et al, 2001

Spawning conditions (100.0%)

Trait id Trait Primary Data Secondary Data References
36 Spawning migration distance Amphibiotique migration in its country of origin No data Agence de l'eau,
37 Spawning migration period Enter freshwater from May to October in a sexually immature condition, remain in rivers all winter (often more than six months), and spawn the following spring ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October'] Robards and Quinn, 2002
37 Spawning migration period Spawning runs start when water temperature are between 1 and 15, but are most commonly in the 9-10°C range No data Kerr and Grant, 1999
38 Homing Generally there is a high degree of homing by spawning adults Present Scott and Crossman, 1973
38 Homing Fish return to natal streams to spawn as mature adults Present Tipping, 1991
39 Spawning season December through April, January trough March, Spring ['January', 'March', 'April', 'May', 'June', 'December'] Internet, 2005
39 Spawning season January to July [Mainly from mid-April to June] ['January', 'February', 'March', 'April', 'May', 'June', 'July'] Groot, 1996
39 Spawning season Begin in December ['December'] Duston and Bromage, 1986
39 Spawning season February to June [Really rare in Europe] ['February', 'March', 'April', 'May', 'June'] Bruslé and Quignard, 2001
39 Spawning season October to May ['January', 'February', 'March', 'April', 'May', 'October', 'November'] Billard, 1997
39 Spawning season October to May ['January', 'February', 'March', 'April', 'May', 'October', 'November'] Fishbase, 2006
39 Spawning season Basically spring spawner: from March to August, mainly from mid-April to late-June ['March', 'April', 'May', 'June', 'July', 'August'] Scott and Crossman, 1973
39 Spawning season Spawning takes place from March to August but is usually in spring [North America Great Lakes fish spawn from late December to late April] ['March', 'April', 'May', 'June', 'July', 'August', 'December'] Coad, 2006
39 Spawning season Rainbow trout are basically spring spawners, although some autumn and winter spawning has been observed ['January', 'February', 'March', 'April', 'May', 'June', 'October', 'November', 'December'] Kerr and Grant, 1999
39 Spawning season Mid-November to January ['January', 'November'] Terver, 1984
39 Spawning season Unlike other salmonids in Newfoundland, rainbow trout spawn in the spring, usually from mid-April to mid-May, although lake-resident trout may spawn as early as late March in cetains areas of Newfoundland ['March', 'April', 'May', 'June'] Bradbury et al, 1999
39 Spawning season Rainbows (including steelhead) and cutthroats characteristically breed in late winter, spring and summer ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September'] Willson, 1997
39 Spawning season Pacific salmon spawn in fall (though this may be as early as July or as late as February, depending on species and region) whereas the Pacific trout species (formely in the genus Salmo) spawn in spring. ['February', 'April', 'May', 'June', 'July', 'October', 'November', 'December'] Quinn and Myers, 2004
39 Spawning season The controls under the simulated natural seasonal cycle spawned in January/February at the same time as fish of the same strain in outside tanks under ambiant day-length ['January', 'February'] Bromage et al, 1984
39 Spawning season Spring spawner [Other authors described between October and March] ['January', 'February', 'March', 'April', 'May', 'June', 'October', 'November'] Humpesch, 1985
40 Spawning period duration 4 4.0 weeks Duston and Bromage, 1986
40 Spawning period duration 2-6 4.0 weeks Kerr and Grant, 1999
40 Spawning period duration 8-9 8.5 weeks Terver, 1984
40 Spawning period duration Reproduction in the rainbow trout is an annual event, with spawning confined to a brief (typîcally 6-8 week) period each year 7.0 weeks Randall et al, 1998
40 Spawning period duration From April 9 to April 19, 1931 9.0 weeks Greeley, 1932
40 Spawning period duration Each individual brrodstock producing eggs over a 6-8 weeks period 7.0 weeks Bromage et al, 1992
41 Spawning temperature 10-15.5 12.75 °C Internet, 2005
41 Spawning temperature 4-19 [6-8 or 10-13] 11.5 °C Barton, 1996
41 Spawning temperature From 4 to 13°C with a peak at 8°C 4.0 °C Groot, 1996
41 Spawning temperature 10-13 [Optimum temperature] 11.5 °C Bruslé and Quignard, 2001
41 Spawning temperature Usually between 10.0-15.5 12.75 °C Scott and Crossman, 1973
41 Spawning temperature Usually exceeds 10, but may be 5-13°C 9.0 °C Coad, 2006
41 Spawning temperature Basically at 3.9-9.4°C, but also described at 10-15°C 6.65 °C Kerr and Grant, 1999
41 Spawning temperature 6 [Temperature at which spawning is typically initiated] 6.0 °C Olden et al, 2006
41 Spawning temperature 4-11 7.5 °C Kamler et al, 1996
42 Spawning water type Large tributaries of river system, some coastal creeks, smaller tributaries within the estuary No category Internet, 2005
42 Spawning water type Spawning occurs in many small streams: cool, clear and well-oxygenated waters, with water velocities of 23-155 cm/sec Flowing or turbulent water Groot, 1996
42 Spawning water type Smaller tributaries of their rivers, or inlet or outlet streams of their lakes [in a riffle above a pool] Stagnant water Scott and Crossman, 1973
42 Spawning water type Permanent headwater tributaries with cool, cela water that is well oxygenated [Water velocities of 23 to 155 cm/m] Flowing or turbulent water Kerr and Grant, 1999
42 Spawning water type Upwelling does not appear to be important for spawning of rainbow trout No category Bradbury et al, 1999
42 Spawning water type Streams, lakes Stagnant water Willson, 1997
42 Spawning water type The ability of chum salmon and rainbow trout to detect upwellling currents, and the reduction in digging variability associated with development of the nest, suggest that the current pattern around the nest provides important locative information for the females. Flowing or turbulent water Tautz and Groot, 1975
42 Spawning water type Headwater spring streams to large , lower-crouese streams No category Greeley, 1932
43 Spawning depth Between 10 and 150 cm 10.0 m Groot, 1996
43 Spawning depth 0.-1.5 m 0.75 m Kerr and Grant, 1999
43 Spawning depth Almost exclusively on shallow, gravel bottomed streams, <1.5 m 1.5 m Bradbury et al, 1999
44 Spawning substrate Gravel Lithophils Internet, 2005
44 Spawning substrate Optimal gravel size range from 1.5-6 for spawners smaller than 50 cm and 1.5-10 forfemales larger than 50 cm Lithophils Groot, 1996
44 Spawning substrate Bed of fine gravel Lithophils Scott and Crossman, 1973
44 Spawning substrate Lithophils Lithophils Balon, 1975
44 Spawning substrate Lithophils Lithophils Kamler et al, 1996
44 Spawning substrate Gravels Lithophils Greeley, 1932
45 Spawning site preparation Nest building continues day and night and genrally the female gis several nests (two to five) in succession No category Groot, 1996
45 Spawning site preparation The female finds a spot and digs a pitt Susbtrate chooser Fishbase, 2006
45 Spawning site preparation The female digs a redd Susbtrate chooser Scott and Crossman, 1973
45 Spawning site preparation A female excavates a redd by lying on her side and thrashing her tail Susbtrate chooser Coad, 2006
45 Spawning site preparation Brood hiders Susbtrate chooser Balon, 1975
45 Spawning site preparation Spawning behavior in both chum salmon and rainbow trout consists of a combination of nest building by the female and courtship display by the male, leading to deposition of fertilized eggs in the nest [more details provided in the article] No category Tautz and Groot, 1975
45 Spawning site preparation Brood hiders Susbtrate chooser Kamler et al, 1996
45 Spawning site preparation The digging of spawning pit is exclusively a phase of female behavior Susbtrate chooser Greeley, 1932
45 Spawning site preparation Nest by female Best build by female Fleming, 1998
46 Nycthemeral period of oviposition Nest building takes place day and night Day Scott and Crossman, 1973
46 Nycthemeral period of oviposition Most spawning takes place in the morning and evening and nest may be adandonned the day Day Coad, 2006
46 Nycthemeral period of oviposition Nest constrution occurs both day and night Day Kerr and Grant, 1999
46 Nycthemeral period of oviposition Spawnig observations were as follows: 10:30 A.M (one record) and 4:30 to 6:45 P.M. (six records) Day Greeley, 1932
47 Mating system By pair are side by side Monogamy Fishbase, 2006
47 Mating system Females dig and spawn in several nests with the same or other males No category Scott and Crossman, 1973
47 Mating system The spawning act last 5-8 s with the pair parallel in the redd pressed together, both fish gape, arch and vibrate [Other males may shade sperm] No category Coad, 2006
47 Mating system The two males, one slightly larger than the female, and the other typically a younger, smaller male not so large as either fish, quickly take positions, one at either side of the female [Both males and females participate in several mating acts before becoming entirelyfinished with the reprodcutive activities of a single season] No category Greeley, 1932
48 Spawning release The whole process is repeated for several days until the female deposists all her eggs Multiple Fishbase, 2006
48 Spawning release Deposited in loose cluster or piles Fractional Internet, 2005
48 Spawning release Females lay about 800-1000 eggs in each nest pocket No category Groot, 1996
49 Parity Not all rainbow trout die after spawning [The trend toward repeat spawning increases from north to south] Iteroparous Groot, 1996
49 Parity Individual rainbow trout have been known to spawn in as many as five successive years, however survival is often low and the number spawning more than once can be less than 10% Iteroparous Scott and Crossman, 1973
49 Parity Repeat spawning can occur for up to 5 years Iteroparous Coad, 2006
49 Parity All members of the genus Oncorhynchus(including anadromous and non-anadromous forms) die after spawning, and this is true with three exceptions. First the Pacific trout species, are all iteroparous. Second, male masu salmon (O. masou) that mature in fresh water as parr are capable of surviving, migrating to sea, and spawning in subsequent season, though anadromous males and females are semelparous. Third, under experimental conditions male chinhook salmon can mature as parr, survive spawning, grow, and spawn again the following year, and even a third year. Iteroparous Quinn and Myers, 2004
49 Parity Mean of 10 (range 0.6-31.3%) of repeat spawners for anadromous populations, and 26 (range 18-33%) for resident populations No category Fleming, 1998
50 Parental care Female continues to stay over the redd site to further shape the gravel mound and to defend the area against other females [Female stellhead do not guard their redds after spawning and tend to leave the spawning area] No care Groot, 1996
50 Parental care Nest may be adandonned the day No category Coad, 2006
50 Parental care Eggs are not guarded by either parents No care Kerr and Grant, 1999
50 Parental care Female steelhead reportdly do not nest-guard No care Willson, 1997
50 Parental care The female, throughout the long period of egg covering (a process continued for one to several hours) resents the presence of any fish at or just above the spot where the eggs lie [Male defence lasts only trough early stages of egg covering] No category Greeley, 1932
50 Parental care No protection by female No care Fleming, 1998