Salvelinus namaycush

  • Scientific name
  • Salvelinus namaycush (Walbaum, 1792)

  • Common name
  • Lake trout

  • Family
  • Salmonidae

  • External links
  • Fishbase
Trait completeness 68%
Total data130
References27
Image of Salvelinus namaycush

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail



Egg (100%)


Trait id Trait Primary data Secondary Data References
4 Egg adhesiveness Fertilized eggs fall into crevices of the spawning substrate Non-Adhesive Kerr and Grant, 1999
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 105-147 126.0 days Bruslé and Quignard, 2001
5 Incubation time 105-147 [15-21 weeks] 126.0 days Perrin, 2001
5 Incubation time 15-21 weeks, hatching normally occurs between mid-February and late March 18.0 days Fishbase, 2006
5 Incubation time 105-147 [15-21 weeks at 0.3-1°C] 126.0 days Scott and Crossman, 1973
5 Incubation time Normally hatch in about 50 days at 10°C [15 to 21 weeks at temperatures between 0.1-10°C] 5.05 days Kerr and Grant, 1999
5 Incubation time 150.0 [Mean time to egg hatch within the range of average post-spawning water temperatures] 150.0 days Olden, 2006
5 Incubation time Incubate for 4-5 months over winter 4.5 days Bradbury, 1999
5 Incubation time Initial hatch after 70 days and 90% hatch after 81 days at 7°C and 49 days and 56 days at 10°C respectively 70.0 days Carlson and Siebert, 1974
5 Incubation time 162.3 [1.83°C], 86.3 [5.1°C], 80.5 [6.72°C], and 49 [10°C] 162.3 days Embody, 1934
5 Incubation time Eggs hatch in 2-5 months at 47-35°F, in late January-May 3.5 days Goodyear, 1982
7 Degree-days for incubation 500 500.0 °C * day Perrin, 2001
7 Degree-days for incubation 440 440.0 °C * day Pennel and Barrington (79), 1996
7 Degree-days for incubation 490 490.0 °C * day Bascinar and Okumus, 2004
7 Degree-days for incubation Hatching occured several weeks before the experiments at about 450-500 DD 475.0 °C * day Gunn and Noakes, 1987
7 Degree-days for incubation About 500-550 [Initial hatch after 70 days and 90% hatch after 81 days at 7°C and 49 and 56 at 10°C respectively] 525.0 °C * day Carlson and Siebert, 1974
6 Temperature for incubation 0.3-1 in normal conditions 0.65 °C Scott and Crossman, 1973
6 Temperature for incubation 5-9 during incubation period 7.0 °C Beauchamp, 1992
6 Temperature for incubation < 10°C for optimal egg incubation 10.0 °C Kerr and Grant, 1999
6 Temperature for incubation Separate lots of eggs were reared at different temperatures: 0.5-6°C 3.25 °C Gunn and Noakes, 1987
6 Temperature for incubation Test temperatures were 7 and 10°C within the optimum range and near the higher limit for incubation 7.0 °C Carlson and Siebert, 1974
6 Temperature for incubation Could be incubated at 1.8°C 1.8 °C Babiak and Dabrowski, 2003
2 Egg size after water-hardening 5.7 ± 0.2 [Fertilized eggs] 5.7 mm Beauchamp, 1992
2 Egg size after water-hardening 3.7-6.8, with a mean of 5.0 [Size of ripe egg] 5.25 mm Groot, 1996
2 Egg size after water-hardening 5.4 [Fully hardened eggs] 5.4 mm Penaz, 1981
3 Egg Buoyancy Demersal (on the bottom) Demersal Fishbase, 2006
3 Egg Buoyancy Demersal [Fertilized egg fall into the crevices between the large rocks] Demersal Scott and Crossman, 1973
3 Egg Buoyancy The eggs of Salmonidae are buried in unguarded nests called 'redds' and are demersal-nonadheive No category Kunz, 2004
3 Egg Buoyancy Shortly after release, eggs settle to the bottomand lodge in crevices among rocks No category Bradbury, 1999
3 Egg Buoyancy Eggs usually incubate in crevices in the susbtrate Demersal Goodyear, 1982
1 Oocyte diameter 4.5-6 5.25 mm Bruslé and Quignard, 2001
1 Oocyte diameter 5-6 [Not specified] 5.5 mm Perrin, 2001
1 Oocyte diameter 5-6 5.5 mm Fishbase, 2006
1 Oocyte diameter 5-6 [In ovary, at maturity] 5.5 mm Scott and Crossman, 1973
1 Oocyte diameter 5-6 [Not specified, but seems unswollen] 5.5 mm Mittelbach and Persson, 1998
1 Oocyte diameter 5.5 [Mean diameter of mature, fully yolked, ovarian oocyte] 5.5 mm Olden, 2006

Larvae (57%)


Trait id Trait Primary Data Secondary Data References
11 Temperature during larval development 10.8°C preferred by fingerlings [11.7°C preferred for yearlings] 10.8 °C Kerr and Grant, 1999
11 Temperature during larval development Reared at 4.9 ± 0.1°C 4.9 °C Gunn and Noakes, 1987
14 Onset of exogeneous feeding About 140 [Initial feeding started at 101 days after fertilization and 90% hatch occured at 81 days at 7°C and 60 days after fertilization and 90% hatch at 10°C, i.e. 20 days at 7°C and 14 days at 10°C] 140.0 °C * day Carlson and Siebert, 1974
8 Initial larval size 16 16.0 mm Mittelbach and Persson, 1998
8 Initial larval size 15.2 15.2 mm Kerr and Grant, 1999
8 Initial larval size 16.1 16.1 mm Olden, 2006
9 Larvae behaviour Fry remain on the spawing shoals about a month or so after hatching while the yolk sac is being absorbed Demersal Kerr and Grant, 1999
9 Larvae behaviour Upon hatching alevins remain near the bottom in spawning areas for several weeks to three months before moving to deeper water Demersal Bradbury, 1999
9 Larvae behaviour Remain in crevices in susbrate for about 1 month Demersal Goodyear, 1982

Female (42%)


Trait id Trait Primary Data Secondary Data References
24 Maximum GSI value Mean of 14.6 (range 12.3-17.6%) for different populations 14.95 percent Fleming, 1998
19 Relative fecundity 0.8-2.4 1.6 thousand eggs/kg Bruslé and Quignard, 2001
19 Relative fecundity 2-16 9.0 thousand eggs/kg Perrin, 2001
19 Relative fecundity 0.9-2.6 1.75 thousand eggs/kg Mittelbach and Persson, 1998
19 Relative fecundity The number of eggs deposited depends on the size of the female but ranges from 400-1200 eggs per pound of female 800.0 thousand eggs/kg Scott and Crossman, 1973
27 Age at sexual maturity 6-7 [Sex not specified] 6.5 years Billard, 1997
27 Age at sexual maturity 6-7 [Not specified] 6.5 years Scott and Crossman, 1973
27 Age at sexual maturity Mostly between 4 to 13 [Both sex], river spawning male trout were found to mature aty 7 [In most cases, males mature over a year earlier than females] 4.0 years Kerr and Grant, 1999
27 Age at sexual maturity 5.0 [Both sex] 5.0 years Olden, 2006
27 Age at sexual maturity In Labrador, lake trout usually attain sexual maturity in 6-11 years [Not specified] 8.5 years Bradbury, 1999
20 Absolute fecundity A 32-inch (813 mm) female from the Great Lakes may deposit up to 18,000 eggs 32.0 thousand eggs Scott and Crossman, 1973
16 Length at sexual maturity 38.0 [Both sex] 38.0 cm Olden, 2006
15 Age at sexual maturity 6-7 6.5 year Pennel and Barrington (77), 1996
15 Age at sexual maturity 6-7 [Sex not specified] 6.5 year Billard, 1997
15 Age at sexual maturity 6-7 [Not specified] 6.5 year Scott and Crossman, 1973
15 Age at sexual maturity Mostly between 4 to 13 4.0 year Kerr and Grant, 1999
15 Age at sexual maturity 5.0 [Both sex] 5.0 year Olden, 2006
15 Age at sexual maturity In Labrador, lake trout usually attain sexual maturity in 6-11 years [Not specified] 8.5 year Bradbury, 1999

Male (44%)


Trait id Trait Primary Data Secondary Data References
30 Male sexual dimorphism Male lake char are capable of developing a kype, but they almost never do. Male lake char may be more iridescent than females, sport a black lateral stripe, or develop (in soem populations) breeding tubercles, but generally they show less sexual dimoprhism than other char do [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 and snouts 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 Breeding tubercles present Present Kratt and Smith, 1978
30 Male sexual dimorphism Males are bigger than females Absent Fleming, 1998
33 Maximum GSI value Mean of 3.1 for different population 3.1 percent Fleming, 1998
28 Length at sexual maturity 38.0 [Both sex] 38.0 cm Olden, 2006

Spawning conditions (93%)


Trait id Trait Primary Data Secondary Data References
47 Mating system By pair, on occassion as many as seven males and three females may engage in a mass spawning act Monogamy Fishbase, 2006
47 Mating system One or two males may spawn with one female, or a group of males and females may spawn together, extruding eggs and sperm over rocky bottom Promiscuity Scott and Crossman, 1973
47 Mating system A male will court many females within its range [Lake trout visit and probably spawn on more than one shoal] Polygyny Kerr and Grant, 1999
47 Mating system Disperse to deeper water several weeks after spawning No category Goodyear, 1982
46 Nycthemeral period of oviposition The spawning act occurs mostly at night, with peak spawning between dusk and 9 or 10 pm Ambiguous Fishbase, 2006
46 Nycthemeral period of oviposition Spawning occur in the night, mostly from 19-22 Night Scott and Crossman, 1973
46 Nycthemeral period of oviposition Most spawning takes place during the hours of darkness between dusk and 2300 hours Dusk Kerr and Grant, 1999
50 Parental care Nonguarders No care Fishbase, 2006
50 Parental care Dispersal of adults from spawning areas begins shortly after spawning No care Bradbury, 1999
50 Parental care Parental care is absent in coregonids and lake char No care Willson, 1997
50 Parental care No defence No care Fleming, 1998
44 Spawning substrate Gravels Lithophils Perrin, 2001
44 Spawning substrate Most often occurs over a large boulder or rubble bottom No category Scott and Crossman, 1973
44 Spawning substrate Mostly over cobble, boulder and borken rock substrates, only once on macrophytes Lithophils Beauchamp, 1992
44 Spawning substrate Lake trout ave very selective in their choice of sites for spawning: good spawning substrate consists of clean cobble, boulder or broken angular rock with large interstices that provide protection to eggs [Prefereed spawinng grounds consist of largest diameter rock rock with three to 15 cm and is common,ly interspersed with larger boulders, average diameter of 4.3] Lithophils Kerr and Grant, 1999
44 Spawning substrate Lithophils Lithophils Balon, 1975
44 Spawning substrate The spawning substrate is usually composed of large gravel (>2 cm in diameter), cobble and rubble interspered with boulders and is generally free of sand, mud, detritus and vegetation. Ambiguous Bradbury, 1999
44 Spawning substrate The spawning rubble, consisting of broken, mixed pieces (about 10-30 cm length) of quarzite, feldspar, and granite, is underlain with solid bedrock Lithophils Gunn and Keller, 1984
44 Spawning substrate Eggs are broadcast by shallow-water races over rough, silt-free bottom, including honeycomb rock, rubble, boulders, and gravel, deep-water races spawn over clay, sand, mud, and silt, planter varieties spawn over all substrates Ambiguous Goodyear, 1982
45 Spawning site preparation Open water / substratum egg scatterers [Males reach spawning beds first and spend some time cleaning the rocks] Open water/substratum scatter Fishbase, 2006
45 Spawning site preparation Cleaning of the spawning grounds consisted of brushing the rocks with body or tail fin, or rubbing then with the snout No category Scott and Crossman, 1973
45 Spawning site preparation The males appear to clean the rocks with her tails but do not build a nest No category Kerr and Grant, 1999
45 Spawning site preparation Brood hiders Susbtrate chooser Balon, 1975
45 Spawning site preparation No nest Open water/substratum scatter Fleming, 1998
41 Spawning temperature 4.5-14 9.25 °C Pennel and Barrington (79), 1996
41 Spawning temperature < 10 10.0 °C Bruslé and Quignard, 2001
41 Spawning temperature Starts when temperature below 10°C 10.0 °C Perrin, 2001
41 Spawning temperature From 8-9 to 10.6-13.9°C 8.5 °C Scott and Crossman, 1973
41 Spawning temperature 8-11 9.5 °C Mittelbach and Persson, 1998
41 Spawning temperature 9-13 [Onset of spawning appears to be stimulated by heavy winds when water temperatures drop to near 10°C, Increase and prolonged cloud cover can also advance the spawning period] 11.0 °C Kerr and Grant, 1999
41 Spawning temperature 8 [Temperature at which spawning is typically initiated] 8.0 °C Olden, 2006
40 Spawning period duration The spawning period generally lasts between seven to 18 days, and lake trout spawning in Algouquin Park lakes often occurs during the latter portion of October and lasts for 10 days 18.0 weeks Kerr and Grant, 1999
42 Spawning water type Inland lakes, rarely in rivers Stagnant water Scott and Crossman, 1973
42 Spawning water type Mounds No category Beauchamp, 1992
42 Spawning water type Spawn in shallow inshore areas of lakes, rarely in streams [Spawning areas are often exposed to prevaling winds that wave action and water currents keep the area free of sand, silt and detritus] Ambiguous Bradbury, 1999
42 Spawning water type Lakes, streams Stagnant water Willson, 1997
42 Spawning water type Areas with current, including shorelines, reefs, shoals, ledges, bars, channels, bays, river mouths, and rivers Ambiguous Goodyear, 1982
43 Spawning depth Depth of less than 12.2, and sometimes as shallow as 30 cm 12.2 m Scott and Crossman, 1973
43 Spawning depth Deep water (40-60 m ) over beds of macrophytes [Only one report] 50.0 m Beauchamp, 1992
43 Spawning depth Lake trout spawn at a great variety of depths, less than 36.6 m [Most inland lake spawning shoals are less than six meters deep, also observed between 15 cm to 3.7 m deep] Some population choose to spawn over deep-water mounds (40-60 m) covered with beds of Clara delicauta 50.0 m Kerr and Grant, 1999
43 Spawning depth Spawn over a variety of depths rangin from 0.5-55m, or greater than 100 m. In larger lakes, psanwing typically occurs at depths between 5 and 10 m, while in smaller lakes spawning has been reported to occur at depths between 0.1-5 m 27.75 m Bradbury, 1999
43 Spawning depth Few inches - 600 feet, depending on race of Lake trout, planted varieties usually at depths less than 30 feet 600.0 m Goodyear, 1982
37 Spawning migration period Move from deep water to spawning grounds in shallower water on offshore reefs, in littoral waters, or in tributaries. Movement usually begins in late August or September, fish arrive on grounds 1-2 weeks before spawning begins ['August', 'September'] Goodyear, 1982
39 Spawning season October-November ['October', 'November'] Billard, 1997
39 Spawning season September to November or during winter ['March', 'January', 'September', 'February', 'November'] Bruslé and Quignard, 2001
39 Spawning season November-December, but also August-September and until January ['January', 'September', 'August', 'December', 'November'] Fishbase, 2006
39 Spawning season Mainly occurs in October, sometimes as early as September in the north or as late as November in south ['October', 'November', 'September'] Scott and Crossman, 1973
39 Spawning season October-November ['October', 'November'] Beauchamp, 1992
39 Spawning season Primarily fall spaweners although reprodcution is know to occur as early as June in Lake Superioir and as late as January in Lake Tahoe, Nevada ['January', 'June'] Kerr and Grant, 1999
39 Spawning season On most areas of Canada, spawning occurs in late summer-early fall, mainly in September or October in Labrador. Several investigators have suggested that declining water temperatures and photoperiod coupled with stron on-shore winds are necessary factors triggering spawning ['October', 'August', 'July', 'September'] Bradbury, 1999
39 Spawning season Salmo and most char are fall breeders, although a few populations of Arctic char breed in spring ['April', 'May', 'June'] Willson, 1997
39 Spawning season Most spawning occurs in October and November when temperature is falling from 58 to 37°F, however some races may begin spawning in June ['October', 'November', 'June'] Goodyear, 1982
38 Homing In certain lakes, he returns to natal spawning grounds Present Perrin, 2001
38 Homing Evidence of homing Present Scott and Crossman, 1973
48 Spawning release Batch spawner, the spawning act (one female and one or two males) is repeated until the female releases all her eggs Mutliple Fishbase, 2006
49 Parity Spawning occurs annually in southern areas, every other year in other parts No category Fishbase, 2006
49 Parity Can live to 40 years of age No category Kerr and Grant, 1999
49 Parity Dispersal of adults from spawning areas begins shortly after spawning No category Bradbury, 1999
49 Parity Lake char females commonly breed in alternate years, especially in the north. These fish are potentially long lived (>25 years), and indiduals may reproduce many times if maturity is not delayed No category Willson, 1997
49 Parity Mean of 53 (range 6-79%) of repeat spawners in different populations No category Fleming, 1998