Thymallus thymallus

  • Scientific name
  • Thymallus thymallus (Linnaeus, 1758)

  • Common name
  • Grayling

  • Family
  • Thymallidae

  • External links
  • Fishbase
Trait completeness 90%
Total data287
References49
Image of Thymallus thymallus

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail



Egg (100%)


Trait id Trait Primary data Secondary Data References
4 Egg adhesiveness Slightly adhesive Adhesive Crisp, 1996
4 Egg adhesiveness Salmonidae, whose eggs are not sticky Non-Adhesive Woynarovich, 1962
4 Egg adhesiveness The eggs of the grayling are just very slighlty sticky Adhesive Penaz, 1975
5 Incubation time 105.8 [2°], 41.4 [6°C], 16.7 [12°C], 10.8 [16°C] 105.8 days Jungwirth and Winkler, 1984
5 Incubation time 15-20 [10°C] 17.5 days Bruslé and Quignard, 2001
5 Incubation time 16-21 [9.0-10.5°C] 18.5 days Zaytsev, 1986
5 Incubation time 18-30, and about 18-20 at 10°C 24.0 days Maitland, 1977
5 Incubation time Estimates of the number of days required for 50% of egg to hatch: 51 [5°C], 20 [10°C], and 11 [15°C] [In different populations: 17-28 [At 3.5-18.8°C], 12-16 [At 3.3-19°C], 17-29 [At 4.0-18.0°C]] 22.5 days Humpesch, 1985
5 Incubation time At mean water temperature of 10.2°C, the incubation (till the hatching of 50% of embryos) lasts, in one experiment, 387 hours, in the second one, 409 hours, at 13.0°C, 242 hours [Others stated: 22-23 days at 8.5-9°C, 22 days at 8-10°C, 14-25 at 8°C] 22.5 days Penaz, 1975
5 Incubation time Time of embryonic development till mass hatching is from 37 days at temperature 3.3°C to 7 days at temperature of 16.7°C. In Lopuszna hatchery hatching takes place after 27-46 days 36.5 days Kokurewicz, 1980
5 Incubation time 26 days [At 6.9°C], 15-16 days [At 10°C] 15.5 days Vivier, 1958
7 Degree-days for incubation 150-220 185.0 °C * day Bruslé and Quignard, 2001
7 Degree-days for incubation 160-170 [Under the usual incubation conditions (9.0-10.5°C), mass hatching of lake grayling occured at 16-17 days] 165.0 °C * day Zaytsev, 1986
7 Degree-days for incubation 200 [About 20 days at 10°C] 200.0 °C * day Persat, 2001
7 Degree-days for incubation 180-220 200.0 °C * day Northcote, 1995
7 Degree-days for incubation About 130-340 235.0 °C * day Haugen and Vollestad, 2000
7 Degree-days for incubation 180-200 190.0 °C * day Northcote, 1993
7 Degree-days for incubation 200 [i.e. 20 days at 10°C at ca. optimum temperature] 200.0 °C * day Humpesch, 1985
7 Degree-days for incubation About 200, vary between 150-230 according to different authors 190.0 °C * day Bardonnet and Gaudin, 1990
7 Degree-days for incubation Hatch after a period of 177 degree-days 177.0 °C * day Scott, 1985
7 Degree-days for incubation 113-138 [Effective day-degrees] 125.5 °C * day Kamler, 2002
7 Degree-days for incubation At mean water temperature of 10.2°C, the incubation (till the hatching of 50% of embryos) lasts, in one experiment, 165.2 DD), in the second one, 174.8 DD, at 13.0°C, 130.9 DD. [Described by other authors as: 137 DD at 11.42°C (range 9-13.2°C) and 139 DD at 9.92 (range 6.5-12.75°C), start at 150 and peak hatching at 170, ended at 190 with temperature 8-12°C 11.1 °C * day Penaz, 1975
7 Degree-days for incubation Average evaluation 172 DD. The embryonic development from fertilization till mass hatching is from 122 to 246 DD in laboratories and from 205 to 258 DD in cultures in Lopuszna 172.0 °C * day Kokurewicz, 1980
7 Degree-days for incubation 180-200 appears the closest to reality, also described as low as 160°D 190.0 °C * day Vivier, 1958
7 Degree-days for incubation L'incubation a necessité 200 degré-jours en 1982 (dont 110 jusqu'à l'apparition des yeux) pour un température moyenne de 8.5°C. En 1983, elle en a nécessité 220 (190 à 230 selon les pontes) (T= 9°C). Ces valeurs se situent plutôt au-dessus de celles citées dans la litérature: 200, 180 [At 7°C], 177 [AT 8°C] 200.0 °C * day Carmie, 1985
6 Temperature for incubation 6-13.5 [best results, mortalily reach 100% above 16°C] 9.75 °C Jungwirth and Winkler, 1984
6 Temperature for incubation Mean temperature of incubation is 9.0-10.5°C 9.75 °C Zaytsev, 1987
6 Temperature for incubation 10 10.0 °C Persat, 2001
6 Temperature for incubation 8.5-9.0 8.75 °C Northcote, 1995
6 Temperature for incubation 4.1-7.5 is the temperature range for >50% survival to hatch [<3.0 and >18.5, lethal lower and upper limit] 5.8 °C Crisp, 1996
6 Temperature for incubation 7.9-11.2 Reared conditions tested] 9.55 °C Haugen and Vollestad, 2000
6 Temperature for incubation 10°C 10.0 °C Maitland, 1977
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 Grayling hatch in June No data Kristiansen and Doving, 1996
6 Temperature for incubation At mean water temperature of 10.2°C and 13.0°C 10.2 °C Penaz, 1975
6 Temperature for incubation The most favourable temperatures to embryonic development range from 7 to 13°C in conditions of constant temperatures. The embryos developing at temperature lower than 7.3°C are hatching too early in relation to the morphological advancement and are charcaterized by lower vitality. At temperature higher than 13.8°C the survival is low because of lower vitality and increase of abnormally developed larvae in the hatching 7.0 °C Kokurewicz, 1980
6 Temperature for incubation At 8°C. Eyed eggs (11 days post fertilisation) were acclimated to 12°C in 4 days, when the temperature was raised by 1°C per day 8.0 °C Honkanen, 2005
2 Egg size after water-hardening 2-8.3.0 is the diameter of the egg itself, but the diameter of the swollen eggs with the perivetlline space is 3.25-4.66 mm ] 5.15 mm Zaytsev, 1986
2 Egg size after water-hardening 3.5 [Not specified] 3.5 mm Persat, 2001
2 Egg size after water-hardening 4 [After water-hardening] 4.0 mm Mellinger, 2002
2 Egg size after water-hardening 4.0 [After fertilization] 4.0 mm Northcote, 1995
2 Egg size after water-hardening 3.2-4.0 [Seems to be fertilized eggs] 3.6 mm Bonislawska, 2001
2 Egg size after water-hardening 2-3.5 [Not specified] 2.75 mm Bruslé and Quignard, 2001
2 Egg size after water-hardening 3.27 [Swollen egg diameter] 3.27 mm Penaz, 1975
2 Egg size after water-hardening 3.1 [Fully hardened eggs] 3.1 mm Penaz, 1981
2 Egg size after water-hardening Les œufs sont petits (2.5 to 3.5 mm of diameter) after water-hardening 2.5 mm Vivier, 1958
2 Egg size after water-hardening Après fecondation le diamètre de l'œuf est voisin de 3 mm. Il se stabilise à 4 mm après 75 minutes de durcissement 3.0 mm Carmie, 1985
3 Egg Buoyancy Demersal [Eggs only buried] Demersal Bruslé and Quignard, 2001
3 Egg Buoyancy Brood hiders, Bury their eggs under several centimetres of substratum in gravel nests Demersal Sempeski and Gaudin, 1995
3 Egg Buoyancy Eggs are deposited Demersal Billard, 1997
3 Egg Buoyancy Eggs are deposited a few centimetres below the gravel surface Demersal Haugen and Vollestad, 2000
3 Egg Buoyancy Les œufs ne sont pas visibles à la surface, mais si l'on écarte les pierres et les galets, on les découvre enterrés à une profondeur de 4 centimètres environ. Immédiatement après le frai, les œufs pénètrent lentement entre les pierres, un certain nombre d'entre eux sont entraînes par le courant lorsque les graviers du fond sont remués par des accouplements ultérieurs Demersal Vivier, 1958
1 Oocyte diameter Average 2.5, range 2.0-3.0 [Unfertilized eggs] 2.5 mm Zaytsev, 1986
1 Oocyte diameter Mean 2.67, up to 2.9 [Egg immediately before spawning] 2.67 mm Witkowski, 1989
1 Oocyte diameter 2.5-3.5 3.0 mm Northcote, 1995
1 Oocyte diameter As low as 2.0 up to 3.5 even 4.0 in Europe [Not specified] 2.0 mm Northcote, 1993
1 Oocyte diameter The mean size of non-inseminated eggs was 2.49 mm 2.49 mm Penaz, 1975
1 Oocyte diameter Range: 3.02-4.64, mean 3.89 3.83 mm Purtscher and Humpesch, 2006
1 Oocyte diameter 2 mm (1.8 mm at Nant de Sion) 2.0 mm Vivier, 1958
1 Oocyte diameter Dimètre des ovules des de 3 mm 3.0 mm Carmie, 1985

Larvae (86%)


Trait id Trait Primary Data Secondary Data References
11 Temperature during larval development 9.0-10.5°C 9.75 °C Zaytsev, 1986
11 Temperature during larval development Water observed at emergence ranged from 11.6 to 14.5°C 11.6 °C Sempeski and Gaudin, 1995b
11 Temperature during larval development 12-18 [Between 12-18 the larvae spend 5 to 10 days in the gravel] 15.0 °C Northcote, 1993
11 Temperature during larval development Reared at 10.4°C 10.4 °C Bardonnet and Gaudin, 1990
11 Temperature during larval development Over the study, water temperature ranged between 8.0°C and 14°C, and averaged 11.1°C 8.0 °C Scott, 1985
10 Reaction to light They have negative phototaxis, and search for contact with the ground and the shelter Photopositive Zaytsev, 1986
10 Reaction to light The fry emerge from the gravel during the day, with a peak shortly after sunrise Photopositive Northcote, 1995
10 Reaction to light The fry emerge from gravel during the dawn, day Photopositive Bardonnet and Gaudin, 1990
10 Reaction to light The embryos show no photophobia nor a tendency towards crowding. Few days after, hatched mebryos, now much more mobile, show positive rheophilia and photophobia as well as marked tendency towards seeking shelter, under the conditions of artificial culture, they also tend to forming crowds in the corners of the hatching vessels and rearing apparatus. Photopositive Penaz, 1975
13 Full yolk-sac resorption 130-150 [13-14 at 9.0-10.5°C] 140.0 °C * day Zaytsev, 1986
13 Full yolk-sac resorption About 130 130.0 °C * day Haugen and Vollestad, 2000
13 Full yolk-sac resorption Remain within the gravel during 120-150 DD until their yolk sac is almost fully resorbed 135.0 °C * day Bardonnet and Gaudin, 1990
13 Full yolk-sac resorption Complete absoprtion of the yolk sac did not occur until fish reached a size of about 22 mm 22.0 °C * day Scott, 1985
13 Full yolk-sac resorption On the 17-24 th after hatching, the yolk sac is completely resorbed and the larvae rely on exogeneous food only 20.5 °C * day Penaz, 1975
13 Full yolk-sac resorption La vésicule se résorba en 8 jours (degrés-jours de 90) et les alevins furent alimentés avant disparition de celle-ci 8.0 °C * day Vivier, 1958
13 Full yolk-sac resorption La durée moyenne de résorption est de 90 degré-jours 90.0 °C * day Carmie, 1985
14 Onset of exogeneous feeding 100-110 [10-11 days at 9.0-10.5°C] 105.0 °C * day Zaytsev, 1986
14 Onset of exogeneous feeding On the 8th day after hatching (at 10°C), the embryos, having attained the length of 15 mm, were observed to ingest exogeneous food for the first time 8.0 °C * day Penaz, 1975
14 Onset of exogeneous feeding Change to active feeding 4-5 days after hatching 4.5 °C * day Kokurewicz, 1980
14 Onset of exogeneous feeding 40 à 50 degré-jours après l'éclosion, à une taille moyenne de 15 mm, les alevins commencent à gober les particules. 40.0 °C * day Carmie, 1985
8 Initial larval size 10 10.0 mm Bruslé and Quignard, 2001
8 Initial larval size 10.9-11.1 11.0 mm Zaytsev, 1986
8 Initial larval size 10-12 11.0 mm Northcote, 1995
8 Initial larval size About 15-30 mm at emergence 22.5 mm Sempeski and Gaudin, 1995b
8 Initial larval size 10-12 [size at hatching] 11.0 mm Northcote, 1993
8 Initial larval size The length of newly hatched embryos averages 12.4 mm, also described by others as 11.5-13.5 mm 12.5 mm Penaz, 1975
8 Initial larval size Range: 8.57-12.00, mean 10.63 10.285 mm Purtscher and Humpesch, 2006
9 Larvae behaviour Stay in the gravel the first week, then become pelagic Demersal Bruslé and Quignard, 2001
9 Larvae behaviour Prolarvae concentrated in groups at the bottom in the corners on the trough, rarely mouving around Demersal Zaytsev, 1986
9 Larvae behaviour Stay in the gravel the first week, until the full absorption of yolk sac Demersal Persat, 2001
9 Larvae behaviour At 12-18°C, larvae spend 5-10 days in the gravel Demersal Northcote, 1995
9 Larvae behaviour The yolk_sac larvae remain buried until the yolk is exhausted Demersal Haugen and Vollestad, 2000
9 Larvae behaviour After emergence from the gravel Demersal Sempeski and Gaudin, 1995b
9 Larvae behaviour The larvae spend a further 4-5 days in the gravel susbtrate before emerging and beginning to feed near the water surface Demersal Scott, 1985
9 Larvae behaviour The hatched embryos are little mobile and mostly lie on one side of the body. From time to time, the embryo swims up to the water column or even to the water surface, then slowly sinks back to the bottom Demersal Penaz, 1975
9 Larvae behaviour Hatching occurs within the gravel, and yolk sac larvae remain within the gravel until the yolk is resorbed. The larvae then emerge from the gravel, fill their swim bladders with air and, for a period, stay in mid-water shoals. After a few days, the take the position closer to the bottom, and the shoals reduce to small groups or single individuals Demersal Gregersen, 2008

Female (83%)


Trait id Trait Primary Data Secondary Data References
18 Female sexual dimorphism Distinguished from the males by their pale colour pattern Present Darchambeau and Poncin, 1997
24 Maximum GSI value Mean of 15.7 but up to 18% [The highest GSI values are observed in March and at the beginning of April] 15.7 percent Witkowski, 1989
19 Relative fecundity 3-6 4.5 thousand eggs/kg Bruslé and Quignard, 2001
19 Relative fecundity 10-31 20.5 thousand eggs/kg Northcote, 1995
19 Relative fecundity 8 8.0 thousand eggs/kg Kunz, 2004
19 Relative fecundity Being either 3 or 6 depending on authors 3.0 thousand eggs/kg Vivier, 1958
19 Relative fecundity 6-7 6.5 thousand eggs/kg Carmie, 1985
27 Age at sexual maturity 1-2 1.5 years Bruslé and Quignard, 2001
27 Age at sexual maturity 2 [Male] 2.0 years Maitland, 1977
27 Age at sexual maturity 2-3 [Male] 2.5 years Fishbase, 2006
27 Age at sexual maturity 1-2 for males, but age 2 dominates 1.5 years Witkowski and Kowalewski, 1988
27 Age at sexual maturity Mostly 3-4, but some at 2 [Male] 3.5 years Northcote, 1995
27 Age at sexual maturity 3-4 [Not specified] 3.5 years Environment agency, 1996
27 Age at sexual maturity Males mature at age of 3-4 years 3.5 years Zaytsev, 1987
27 Age at sexual maturity A few males were found to be mature at age two. At age three, half og the grayling were mature and by age five years all males and females were mature No data Kristiansen and Doving, 1996
27 Age at sexual maturity 2 years for males 2.0 years Vivier, 1958
26 Resting period About two months: May and June No data Witkowski, 1989
22 Onset of oogenesis July and then increase regularly ['July'] Witkowski, 1989
23 Intensifying oogenesis activity The most intense growth takes place as late as autumn and winter (September-March) ['March', 'January', 'September', 'December', 'February', 'October', 'November'] Witkowski, 1989
21 Oocyte development Group-synchronous Group-synchronous Rinchard, 1996
20 Absolute fecundity 1.5-15 according the size 8.25 thousand eggs Persat, 2001
20 Absolute fecundity 10 in large females 10.0 thousand eggs Environment agency, 1996
20 Absolute fecundity From a low of 1.5 to a high over 36 1.5 thousand eggs Northcote, 1993
20 Absolute fecundity 10 for a female of 45 cm long 10.0 thousand eggs Maitland, 1977
20 Absolute fecundity 10-13 [Fecundity varies from 1500 to 28,000 eggs, average 10,000-13,000] 11.5 thousand eggs Zaytsev, 1987
16 Length at sexual maturity 28-35 [Sex not specified] 31.5 cm Persat, 2001
16 Length at sexual maturity Most frequently size of female 29.5-34.5, full range of 22.0-39.6 cm 32.0 cm Witkowski and Kowalewski, 1988
16 Length at sexual maturity Two females (total lengths 25 and 30 cm) 25.0 cm Darchambeau and Poncin, 1997
15 Age at sexual maturity 2-3 even 4 in Nothern areas 2.5 year Bruslé and Quignard, 2001
15 Age at sexual maturity 3-4 [Female] 3.5 year Fishbase, 2006
15 Age at sexual maturity 2-3 [Most females were 3 years old] 2.5 year Witkowski and Kowalewski, 1988
15 Age at sexual maturity Most 4-5, but in some areas at 3 [Female] 4.5 year Northcote, 1995
15 Age at sexual maturity 3-4 [Not specified] 3.5 year Environment agency, 1996
15 Age at sexual maturity 3 [Female] 3.0 year Maitland, 1977
15 Age at sexual maturity Females mature at 4-6 years 5.0 year Zaytsev, 1987
15 Age at sexual maturity At age three, half of the grayling were mature and by age five years all males and females were mature No data Kristiansen and Doving, 1996
15 Age at sexual maturity 3 years for females 3.0 year Vivier, 1958
15 Age at sexual maturity Les géniteurs de troisième génération en pisciculture ont donné des produits sexuels à l'âge de 3 ans, certains étant matures à 2 ans, et ce malgré une croissance plus faible que dans les rivières d'Auvergne 3.0 year Carmie, 1985

Male (78%)


Trait id Trait Primary Data Secondary Data References
30 Male sexual dimorphism Grayling males are brighter than females, sometimes larger, and have longer dorsal and pelvic fins Present Willson, 1997
31 Onset of spermatogenesis Mid-July, slight increase ['July'] Witkowski, 1989
33 Maximum GSI value Mean 1.63, up to 2 [September] 1.63 percent Witkowski, 1989
32 Main spermatogenesis activity August then remained almost constant during the winter ['February', 'August', 'March', 'January'] Witkowski, 1989
35 Resting period 0.3% [Three months after spawning May -July] 0.3 months Witkowski, 1989
28 Length at sexual maturity Most frequently size of female 25.5-35.5, full range of 23.0-42.3 cm 30.5 cm Witkowski and Kowalewski, 1988
28 Length at sexual maturity 28-35 [Sex not specified] 31.5 cm Persat, 2001
28 Length at sexual maturity On each spawning area, only one male (31 cm total length for the upstream site, 34 cm for the downstream site) was territorial for 2 days. Two other males (both about 30 cm total length) did not appear to defend territories. 31.0 cm Darchambeau and Poncin, 1997

Spawning conditions (100%)


Trait id Trait Primary Data Secondary Data References
47 Mating system 10 male following one female, but also two males and one female No category Bruslé and Quignard, 2001
47 Mating system Most by pair, 2 out of 55 included two males with one female Monogamy Poncin, 1996
47 Mating system One female and one male, with few other males around Monogamy Persat, 2001
47 Mating system By pair Monogamy Ah-King, 2004
47 Mating system A spawning act was considered successful when the behavioural sequence observed in a pair included 'apporach', 'quiverin', 'dorsal fin clasping', 'tail crossing', 'head and tail-up posture', and finally 'gaping', associated with the release of eggs en sperm [Of the 25 spawning acts observed, 24 included the female and the territorial male with one spawning act included two males and one female, of the 70 behavioural sequences, 18 involved a second male that joined he pair before spawning] No category Darchambeau and Poncin, 1997
47 Mating system Dans la nature, mâles et femelles nagent côte à côte jusqu'à ce qu'ils aient trouvé le banc de gravier favorable à leur accouplement: ces bancs de gravier délimitent en général des bassins No category Vivier, 1958
46 Nycthemeral period of oviposition The intensity of the spawning reached its maximum at the beginning of the afternoon, when the temperature increase No category Poncin, 1996
46 Nycthemeral period of oviposition Most spawning acts occur in late afternoon and during night Night Sempeski and Gaudin, 1995
46 Nycthemeral period of oviposition Either in the middle of the day or at the end of the day until the beginning of night Ambiguous Bruslé and Quignard, 2001
46 Nycthemeral period of oviposition Spawning events were noted only during the day, spawning can extend throughout the night in favourable thermal conditions Ambiguous Parkinson, 1999
46 Nycthemeral period of oviposition Spawning usually occurs in the afternoon or in the evening when water temperature is at his highest Day Nykänen, 2004
46 Nycthemeral period of oviposition Latter part of the day near the diel temperature maximum Day Northcote, 1995
46 Nycthemeral period of oviposition Latter part of the day near the diel temperature maximum Day Northcote, 1993
46 Nycthemeral period of oviposition The maximum number of spawners were caught between 2100 and 2300 h No category Zaytsev, 1987
50 Parental care Non guarders No care Fishbase, 2006
50 Parental care Non-guarding No care Sempeski and Gaudin, 1995
50 Parental care No care No care Ah-King, 2004
44 Spawning substrate Lithophil : gravels, coarse sand (between 2 to 60 mm) Ambiguous Bruslé and Quignard, 2001
44 Spawning substrate Clean 1-3 cm gravel Lithophils Poncin, 1996
44 Spawning substrate Gravel or sand Ambiguous Billard, 1997
44 Spawning substrate Fine pebble, and fine gravel and also coarse pebbles Lithophils Sempeski and Gaudin, 1995
44 Spawning substrate Prefererred coarse gravel and fine pebbles [From sand, fine gravel, coarse gravel to fine cobble] Ambiguous Nykänen and Huusko, 2002
44 Spawning substrate Lithophil: mainly coarse gravel, pebbles, cobbles and stones Lithophils Meyer, 2001
44 Spawning substrate Fine gravel, gravel but also sand or stones Ambiguous Northcote, 1995
44 Spawning substrate 5 to 15% of sand, 40-70% of gravel (< 2 cm in diameter), 20-30 % small stones (2-10 cm in diamter) and a few larger stones (>10 cm diameter) Ambiguous Crisp, 1996
44 Spawning substrate On gravel Lithophils Environment agency, 1996
44 Spawning substrate Lithophils Lithophils Balon, 1975
44 Spawning substrate Fine gravel shallows with moderate current Lithophils Northcote, 1993
44 Spawning substrate Gravel Lithophils Maitland, 1977
44 Spawning substrate Gravel and gravel-boulder substrate serve as spawning grounds Lithophils Zaytsev, 1987
44 Spawning substrate Gravel Lithophils Bardonnet and Gaudin, 1990
44 Spawning substrate The stream beds consisted of fine gravel (1-2 cm)mixed up with larger pebbles (5-10 cm) and stones (15-25 cm). Lithophils Darchambeau and Poncin, 1997
44 Spawning substrate During spawning, eggs are deposited a few centimetres below the gravel surface Lithophils Gregersen, 2008
44 Spawning substrate Banc de graviers relativement fins (1 à 3 centimètres) No category Vivier, 1958
45 Spawning site preparation No, eggs are only buried No category Bruslé and Quignard, 2001
45 Spawning site preparation Biggest grayling was strougly territorial, other males did not appear to defend territories No category Poncin, 1996
45 Spawning site preparation Eggs are deposited Susbtrate chooser Billard, 1997
45 Spawning site preparation Brood hiders Susbtrate chooser Fishbase, 2006
45 Spawning site preparation Brood hiders, bury their eggs under several centimetres of substratum in gravel nests Susbtrate chooser Sempeski and Gaudin, 1995
45 Spawning site preparation Dig shallow spawning pits (about 5 cm) compared to other salmonids Susbtrate chooser Meyer, 2001
45 Spawning site preparation Spawning territories set up by the males No category Northcote, 1993
45 Spawning site preparation Eggs are deposited on the gravel Susbtrate chooser Maitland, 1977
45 Spawning site preparation The males defend a territory No category Ah-King, 2004
45 Spawning site preparation Egg-burial is a simple form of parental care No category Willson, 1997
45 Spawning site preparation Eggs are buried but not deep within the substrate [No nest is built] Open water/substratum scatter Bardonnet and Gaudin, 1990
45 Spawning site preparation During spawning, eggs are deposited a few centimetres below the gravel surface Susbtrate chooser Gregersen, 2008
45 Spawning site preparation L'extremité de la caudale de la femelle est recourbée et s'enfonce par des mouvements vibratoires dans la gravier. No category Vivier, 1958
41 Spawning temperature 7-12 9.5 °C Bruslé and Quignard, 2001
41 Spawning temperature 8 8.0 °C Poncin, 1996
41 Spawning temperature 7-11 9.0 °C Ovidio, 2004
41 Spawning temperature 11 [Spawning behavior were observed on 28 March and lasted until 8 April] 11.0 °C Parkinson, 1999
41 Spawning temperature 4-7, but sometimes up to nearly 15 5.5 °C Northcote, 1995
41 Spawning temperature 4 to 7, but sometimes up to 15 4.0 °C Northcote, 1993
41 Spawning temperature The maximum water temperature at which spawning takes place is 8-9°C, further increase in temperature leads to resorption of the sex products 8.5 °C Zaytsev, 1987
41 Spawning temperature Average temperature of 8.8°C 8.8 °C Darchambeau and Poncin, 1997
41 Spawning temperature Optimal temperature of 6-10 8.0 °C Maisse, 1987
41 Spawning temperature Lorsque la tempéature de l'eau passe de 4-5°C à 8-9°C. Une chute brutale de la température de l'eau en-dessous de 5°C après le 15 mars s'accompagne d'un ralentissement de la maturation et du blocage des ovulations chez certaines femelles 4.5 °C Carmie, 1985
40 Spawning period duration 10-19 days [Male] and 2-3 days [Female] 14.5 weeks Bruslé and Quignard, 2001
40 Spawning period duration About 2-4 [Male comes first and fight for few weeks for better places) 3.0 weeks Persat, 2001
40 Spawning period duration About 3 weeks from 23 March to 11 April [Males stayed at the spawning grounds on average 12.2 ± 9.84 days and females 7.0 ± 7.6 days] 12.2 weeks Ovidio, 2004
40 Spawning period duration About 2-3 [Males arrived on spawning grounds several days before females, and were detected on these grounds over much longer periods: 10-19 vs 2-3 days respecitively] 2.5 weeks Parkinson, 1999
40 Spawning period duration About 2-3 [The estimated spawning season lasted from 7 May to 1 June] 2.5 weeks Nykänen, 2004
40 Spawning period duration In very warm springs migrations and spawing takes 1.5-2 weeks long, if spring is cold last about a month 1.75 weeks Witkowski and Kowalewski, 1988
40 Spawning period duration Spawning period ran from 6 to 8 April 6.0 weeks Darchambeau and Poncin, 1997
40 Spawning period duration Both males and females return to the lake shortly after spawning, males generally within 15 days and females within 10 days 15.0 weeks Kristiansen and Doving, 1996
40 Spawning period duration La préiode de reproduction elle-même était en moyenne de 10 à 20 jours, pouvant parfois s'abaisser à moins de 10 jours et durer exceptionnellement un peu plus d'un mois 10.0 weeks Vivier, 1958
42 Spawning water type Strong current : 40 to 70 cm/s Flowing or turbulent water Bruslé and Quignard, 2001
42 Spawning water type Water velocities: about 20cm/s Flowing or turbulent water Poncin, 1996
42 Spawning water type In small rivers, where water accelerates (40-60 cm/s) Flowing or turbulent water Persat, 2001
42 Spawning water type Stream-dwelling, mean velocity 47.8 cm/s Flowing or turbulent water Sempeski and Gaudin, 1995
42 Spawning water type 40-70 cm/s Flowing or turbulent water Nykänen and Huusko, 2002
42 Spawning water type Mean velocities of 40-70 Flowing or turbulent water Nykänen, 2004
42 Spawning water type Spawn up rivers and streams, most often small clean tributaries No category Witkowski and Kowalewski, 1988
42 Spawning water type Upstream border of a shallow riffle, varied between 0.33-0.46 m/s Flowing or turbulent water Meyer, 2001
42 Spawning water type Fast-flowing tributaries, streams [Water velocities range from 23 to 90 cm/s] Flowing or turbulent water Northcote, 1995
42 Spawning water type Mostly on the top of gravel riffles in water so shallow that the backs of the spawning fish broke the water surface No category Crisp, 1996
42 Spawning water type European grayling are mainly a river fish, but those in slow flowing parts of rivers migrate to faster flowing tributaries near spawning time, and lae populations all depend on streams for spawning Flowing or turbulent water Northcote, 1993
42 Spawning water type The coastal shoals, and offshore bars with gravel and gravel-boulder substrate serve as spawning grounds. As a rule, these parts have the most intensive circulation of water masses. Stagnant water Zaytsev, 1987
42 Spawning water type Dans un courant rapide (0.75 m par seconde) Flowing or turbulent water Vivier, 1958
43 Spawning depth Shallow : 20 to 50 cm 20.0 m Bruslé and Quignard, 2001
43 Spawning depth Water depth 30-40 cm [Sometimes up to 88 cm] 35.0 m Poncin, 1996
43 Spawning depth About 20-30 cm 25.0 m Persat, 2001
43 Spawning depth Strong selection of depths between 10 and 40 cm, no spawning sites were found at depths of less than 10 cm or more than 60 cm, although these depths were available 10.0 m Sempeski and Gaudin, 1995
43 Spawning depth Depth < 40 cm were clearly avoided, prefereed 30-40 cm, nests were found at 38-106 cm deep 35.0 m Nykänen and Huusko, 2002
43 Spawning depth Seems to prefer water with water depth of 60-80 cm 70.0 m Nykänen, 2004
43 Spawning depth 0.55-1.15 m 0.85 m Meyer, 2001
43 Spawning depth Shallow No data Northcote, 1995
43 Spawning depth 0.2-0.65 0.425 m Crisp, 1996
43 Spawning depth In the net catches from different depths (0.2-10.0 m), most fish with flowing sex products were caught from depth of 0.2-1.5 m, between 1600 and 2400 h 5.1 m Zaytsev, 1987
43 Spawning depth Most spawing occurred in 20-55 cm water depth 37.5 m Darchambeau and Poncin, 1997
43 Spawning depth Dans une eau très peu profonde. Sur 20 unions observées en rivières, 17 eurent lieu alors qu'on voyait le dos des poissons 20.0 m Vivier, 1958
36 Spawning migration distance Spawning migrations ranged from 70 to 4980 m 70.0 km Ovidio, 2004
36 Spawning migration distance Range from 230 to 4980 m 230.0 km Parkinson, 1999
36 Spawning migration distance Mean distances betwen winter site and spawning season site was 2744±1989 (range 130-5970 m ) 2744.0 km Nykänen, 2004
36 Spawning migration distance The maximum length of river sections used by the individual grayling ranged from 4.18-11.28 km 7.73 km Meyer, 2001
36 Spawning migration distance Grayling tagged in the autumn were recaptured in the spawning periods in crekks up to 27 km away from the tagging site 27.0 km Kristiansen and Doving, 1996
36 Spawning migration distance Comme tous les Salmonidés, il effectue des migrations, mais celles-ci sont de courtes amplitudes […] Les migrations de l'Ombre du Svartbäcken, un petit affleunt du Lac Stosjo en Suède, a constacté que, sur 147 sujets marqués, 33 ont été retrouvés au cours de l'année dans un rayon de 4 kilomètres, 2 mâles seulement au moment du frai s'étaient éloignés de 12 kilomètres 147.0 km Vivier, 1958
37 Spawning migration period The spawning migration of grayling from the Volga to its tributaries usually occurs from late March to early May ['March', 'May'] Pavlov, 1998
37 Spawning migration period Migrations started in March, under conditions of decreasing water level and increasing water temperature in a thermal range of 5 to 8°C ['March'] Ovidio, 2004
37 Spawning migration period All migrations started between 18 and 29 March ['March'] Parkinson, 1999
37 Spawning migration period They leaft their overwintering sites during ice break-up and increasing spring fllod, at mean daily water temperature of 0.3-3.7°C, between 28 April to 2 May ['April', 'March', 'January', 'May', 'June', 'February'] Nykänen, 2004
37 Spawning migration period When water temepratures is 4-6°C, which is most often at the end of March or at the beginning of April ['April', 'March'] Witkowski and Kowalewski, 1988
37 Spawning migration period Spawning run (12-25 March), a period of residency (26 March-1 April) and the dowstream migration (2-16 April) ['April', 'March'] Meyer, 2001
37 Spawning migration period Mature grayling from most lake-living populations migrate to streams and rivers after ice-break to spawn No data Haugen and Vollestad, 2000
37 Spawning migration period Mass migration of graylingto spawning grounds takes place only in calm windless weather when the water temperature reaches 3°C (daily fluctuations 2.3-3.9°C) and continues 1-2 days. In case of warming of the water masses along with constant intermixing due to wind, the spawning is delayed and takes place under more favorable conditions (absence of waves) and at a higher temperature. In such cases, the spawning is significantly extended, and the intervals between individual arrivals of spawners is 10-12 days No data Zaytsev, 1987
37 Spawning migration period Ascend tributaries in May/June when water temperature increase to 5°C ['May', 'June'] Kristiansen and Doving, 1996
37 Spawning migration period Mature fish migrating into streams and rivers after ice break No data Gregersen, 2008
39 Spawning season March-April ['April', 'March'] Billard, 1997
39 Spawning season Mach-April until May-June ['April', 'May', 'June'] Bruslé and Quignard, 2001
39 Spawning season Can occur between 23 to 26 March and from 1 to 3 April ['April', 'March'] Poncin, 1996
39 Spawning season March but also up to May in certain areas ['March', 'May'] Persat, 2001
39 Spawning season Mainly March-April, sometimes until May-June ['April', 'March', 'May', 'June'] Fishbase, 2006
39 Spawning season From 23 March to 11 April ['April', 'March'] Ovidio, 2004
39 Spawning season The estimated spawning season lasted from 7 May to 1 June ['May', 'June'] Nykänen, 2004
39 Spawning season April ['April'] Witkowski and Kowalewski, 1988
39 Spawning season March or April to June ['April', 'March', 'June'] Northcote, 1995
39 Spawning season March-May ['April', 'March', 'May'] Environment agency, 1996
39 Spawning season Spring No data Haugen and Vollestad, 2000
39 Spawning season Late March-April to June ['April', 'March', 'June'] Northcote, 1993
39 Spawning season March-May ['April', 'March', 'May'] Maitland, 1977
39 Spawning season Spawn chiefly in spring and summer ['April', 'May', 'September', 'August', 'June', 'July'] Willson, 1997
39 Spawning season Spring spawner [Other authors described between March and May] ['March', 'May'] Humpesch, 1985
39 Spawning season The lake grayling spawns during spring, soon after melting of ice ['April', 'May', 'June'] Zaytsev, 1987
39 Spawning season Spring spawner No data Kristiansen and Doving, 1996
39 Spawning season Spring spawner No data Billard, 1981-1982
39 Spawning season The grayling spawn in spring ['April', 'May', 'June'] Gregersen, 2008
39 Spawning season L'Ombre fraye en France en Mars et Avril No data Vivier, 1958
39 Spawning season A lieu en mars et avril No data Carmie, 1985
38 Homing Behavior homing Present Bruslé and Quignard, 2001
38 Homing High rates of homing in grayling in the basin of the Upper Volga Present Pavlov, 1998
38 Homing No certain, but in other areas grayligng ascened the same tributary year after year during their spawning runs Present Parkinson, 1999
38 Homing In all fish marked in that year, as many as 18.7% came back to spawn to their home stream Present Witkowski and Kowalewski, 1988
38 Homing When mature, the grayling return to their natal streams with great precision to spawn Present Haugen and Vollestad, 2000
38 Homing 240 of 284 (84%) grayling recaptured in the tributaries were found in the tributary where they had been caught and tagged Present Kristiansen and Doving, 1996
48 Spawning release Females deposit their eggs several times and need to rest between spawning acts Mutliple Sempeski and Gaudin, 1995
48 Spawning release Eggs are released in several times Mutliple Bruslé and Quignard, 2001
48 Spawning release Eggs are released several times, usually with the same male and at the same place [From to 10 spawings within 2 days] Mutliple Persat, 2001
49 Parity Iteroparous: 1 or 2 in a lifetime Iteroparous Bruslé and Quignard, 2001
49 Parity Survive after spawning No category Persat, 2001
49 Parity One clear seasonal peak per year No category Fishbase, 2006
49 Parity Seem to spawn almost every year No category Northcote, 1995
49 Parity Could live up to 15 years No category Maitland, 1977
49 Parity Typically iteroparous, although reproduction does not occur every year for some individuals and populations No category Willson, 1997
49 Parity Grayling in Lake Mjosa are consecutive and repetitive spawners No category Kristiansen and Doving, 1996
49 Parity A few exhausted grayling were caught every season drifting downstream after spawning No category Hladik and Kubecka, 2003