Stenodus leucichthys

  • Scientific name

    • Stenodus leucichthys (Güldenstädt, 1772)

  • Common name

    • Inconnu

  • Family

    • Salmonidae

  • External links

    • Fishbase
Trait completeness 76%
Total data98
References16
Image of Stenodus leucichthys

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail

Egg (100.0%)

Trait id Trait Primary data Secondary Data References
1 Oocyte diameter 2.2-2.4 2.3 mm Belyaeva, 2005
1 Oocyte diameter Average 2.5 2.5 mm Fishbase, 2006
1 Oocyte diameter Up to 2.4 [Not specified] 2.4 mm Coad, 2006
2 Egg size after water-hardening 3.1-3.2 3.15 mm Sturn, 1994
2 Egg size after water-hardening 3.1-3.2 [Fully hardened eggs] 3.15 mm Penaz, 1981
3 Egg Buoyancy Demersal [Deposited on the bottom] Demersal Belyaeva, 2005
3 Egg Buoyancy Demersal [On the bottom] Demersal Fishbase, 2006
3 Egg Buoyancy The eggs of Salmonidae are buried in unguarded nests called 'redds' and are demersal-nonadheive Demersal Kunz, 2004
4 Egg adhesiveness Semi-adhesive Adhesive Belyaeva, 2005
4 Egg adhesiveness Slightly adhesive Adhesive Coad, 2006
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 180-220 200.0 days Belyaeva, 2005
5 Incubation time 250-260 255.0 days Chereshnev et al, 2000
5 Incubation time 180-200 190.0 days Coad, 2006
6 Temperature for incubation 0.1-1.2 0.65 °C Belyaeva, 2005
6 Temperature for incubation 4.0 4.0 °C Sturn, 1994
6 Temperature for incubation Range limits: 0.1-8 4.05 °C Mack and Billard, 1984
7 Degree-days for incubation 180-200 [180-220 at 0.1-1.2°C] 190.0 °C * day Belyaeva, 2005
7 Degree-days for incubation 360, i.e. about 91 at 4°C 360.0 °C * day Sturn, 1994

Larvae (57.0%)

Trait id Trait Primary Data Secondary Data References
8 Initial larval size 11 11.0 mm Belyaeva, 2005
8 Initial larval size Average 13.2, range 12.6-14.3 13.45 mm Chereshnev et al, 2000
8 Initial larval size 12.5, mass hatching 12.5 mm Bogdanova, 1978
8 Initial larval size 11.0-11.3 11.15 mm Sturn, 1994
11 Temperature during larval development 1.2-10.6 5.9 °C Belyaeva, 2005
11 Temperature during larval development Two tests: 2.2-6 and 8.8-13.8 4.1 °C Bogdanova, 1978
11 Temperature during larval development From 4 to 14 4.0 °C Sturn, 1994
13 Full yolk-sac resorption 115 [Around 11 days at 11.4°C, the last remnants of the yolk has disappeared and 23 days at 3.8°C] 115.0 °C * day Bogdanova, 1978
13 Full yolk-sac resorption 130 [33 days at 4°C] 130.0 °C * day Sturn, 1994
14 Onset of exogeneous feeding About 30 [Mixed feeding at 3 days at 11.4°C, and 7 days at 3.8°C] 30.0 °C * day Bogdanova, 1978

Female (67.0%)

Trait id Trait Primary Data Secondary Data References
15 Age at sexual maturity 6-7 6.5 year Belyaeva, 2005
15 Age at sexual maturity 7-10 [Sex not specified] 8.5 year Scott and Crossman, 1973
15 Age at sexual maturity 10-12 [Female] 11.0 year Fishbase, 2006
15 Age at sexual maturity Mass maturation for females at 10-12 [But could be as early as 8] 11.0 year Chereshnev et al, 2000
15 Age at sexual maturity 8-10 [Not specified] 9.0 year Maitland, 1977
16 Length at sexual maturity 70-75 72.5 cm Fishbase, 2006
16 Length at sexual maturity Mass maturation for females at 70-75 [But could be as 66.2] 72.5 cm Chereshnev et al, 2000
17 Weight at sexual maturity Mass maturation for females at 4.0-5.0 [But could be 2.53] 4.5 kg Chereshnev et al, 2000
17 Weight at sexual maturity 5.65 pounds at 7 years and 9.75 pounds at 10 years 5.65 kg Scott and Crossman, 1973
18 Female sexual dimorphism The inconnu exhibits little external difference between the sexes, although females can be slightly bigger than same-age males Absent Willson, 1997
19 Relative fecundity 18-35 eggs per 1 g of body weight, not viscera. Also described that the absolute fecundity ranges from 80000 to 420000, for female ranging from means of 3.35 [At 11 years old] to 9.74 [At 17 years old] 26.5 thousand eggs/kg Chereshnev et al, 2000
19 Relative fecundity 23.74 ± 1.14 (group I, n = 12) and 21.24 ± 0.85 (group II, n =26) 23.74 thousand eggs/kg Dyubin, 2007
20 Absolute fecundity 160-400 280.0 thousand eggs Belyaeva, 2005
20 Absolute fecundity 125-325 225.0 thousand eggs Scott and Crossman, 1973
20 Absolute fecundity 80-420 250.0 thousand eggs Chereshnev et al, 2000
20 Absolute fecundity 130-400 265.0 thousand eggs Maitland, 1977
23 Intensifying oogenesis activity July-August [From 7.8% to 18.3%] ['July', 'August'] Chereshnev et al, 2000
24 Maximum GSI value Mean 18.3 but up to 23.5 [First ten day period of August] 18.3 percent Chereshnev et al, 2000
24 Maximum GSI value 26.25 ± 2.02 26.25 percent Kychanov, 1982

Male (56.0%)

Trait id Trait Primary Data Secondary Data References
27 Age at sexual maturity 5-6 5.5 years Belyaeva, 2005
27 Age at sexual maturity 7-10 [Sex not specified] 8.5 years Scott and Crossman, 1973
27 Age at sexual maturity 9-11 [Male] 10.0 years Fishbase, 2006
27 Age at sexual maturity Mass maturation for males at 9-11 [But could be as early as 7] 10.0 years Chereshnev et al, 2000
28 Length at sexual maturity 65-70 67.5 cm Fishbase, 2006
28 Length at sexual maturity Mass maturation for males at 65-70 [But could be as 54.0] 67.5 cm Chereshnev et al, 2000
29 Weight at sexual maturity Mass maturation for females at 2.0-3.5 [But could be 1.47] 2.75 kg Chereshnev et al, 2000
30 Male sexual dimorphism Males develop tubercles on the head and sides of the abdomen during spawning Absent Coad, 2006
33 Maximum GSI value 2.72 ± 0.08 2.72 percent Kychanov, 1982

Spawning conditions (93.0%)

Trait id Trait Primary Data Secondary Data References
36 Spawning migration distance Up to 3000 km 3000.0 km Belyaeva, 2005
37 Spawning migration period The upstream, presumably prespawning migration, is prolonged and apparently continues all summer ['July', 'August', 'September'] Scott and Crossman, 1973
37 Spawning migration period Upstream migration from wintering areas begins at ice break-up ['January', 'February', 'March'] Fishbase, 2006
37 Spawning migration period The prespawning nelma begins migration to its spawning grounds before the ice drift, the mass migration is observed in the first half of June ['June'] Chereshnev et al, 2000
37 Spawning migration period The Caspian inconnu migration into the Volga mouth began in September-Ocotber when the water temperature decreased down to 18-19°C, and it went on 6-7 months ['September'] Dyubin, 2007
39 Spawning season October-November ['October', 'November'] Belyaeva, 2005
39 Spawning season Late summer or earty autumn ['July', 'August', 'September', 'October', 'November', 'December'] Scott and Crossman, 1973
39 Spawning season September to October ['September', 'October'] Fishbase, 2006
39 Spawning season Mass spawning of nelma begins in middle to late September ['September'] Chereshnev et al, 2000
39 Spawning season Spawning takes place in October and November ['October', 'November'] Coad, 2006
39 Spawning season October-November ['October', 'November'] Maitland, 1977
39 Spawning season In summer and early fall ['July', 'August', 'September', 'October', 'November', 'December'] Willson, 1997
40 Spawning period duration 6-8 [Spawning takes place in October and November] 7.0 weeks Coad, 2006
41 Spawning temperature Falls to 6°C 6.0 °C Belyaeva, 2005
41 Spawning temperature 3-6°C 4.5 °C Chereshnev et al, 2000
41 Spawning temperature 0.2-6°C 3.1 °C Coad, 2006
41 Spawning temperature Spawning which occurred at the water temperature of 0.2-6.0°C 3.1 °C Dyubin, 2007
42 Spawning water type Wide areas No category Chereshnev et al, 2000
42 Spawning water type Usually in mid and inferior part of big streams No category Maitland, 1977
42 Spawning water type Streams No category Willson, 1997
43 Spawning depth Shallow No data Belyaeva, 2005
43 Spawning depth Near the surface No data Fishbase, 2006
43 Spawning depth Depth 2-3 m 2.5 m Chereshnev et al, 2000
44 Spawning substrate Grounds covered with sand and gravel Lithophils Belyaeva, 2005
44 Spawning substrate Sandy-pebbly bottom Psammophils Chereshnev et al, 2000
44 Spawning substrate Lithophils Lithophils Balon, 1975
45 Spawning site preparation Open water / substratum egg scatterers Open water/substratum scatter Fishbase, 2006
45 Spawning site preparation The eggs are shed on the river bottom No category Coad, 2006
45 Spawning site preparation Open substratum spawner Open water/substratum scatter Balon, 1975
45 Spawning site preparation Brood hiders Susbtrate chooser Balon, 1975
46 Nycthemeral period of oviposition Spawning begins at dusk, and continuing well into the night Night Fishbase, 2006
47 Mating system A female accompanied by a male swims to the surface near the upstream end of the spawning ground [Female may repeat the spawning act over the downstream portion of the spawning area or may move upstream to the head of the grounds before releaseing more eggs] No category Fishbase, 2006
48 Spawning release Once Total Belyaeva, 2005
48 Spawning release Female may repeat the spawning act over the downstream portion of the spawning area or may move upstream to the head of the grounds before releasing more eggs No category Fishbase, 2006
49 Parity Twice in his lifecycle, with an interval of 2-3 years No category Belyaeva, 2005
49 Parity Suspected that individual fish spawn only once every 2, 3 or 4 years No category Scott and Crossman, 1973
49 Parity Russian fish appear to spawn only every third or fourth year No category Fishbase, 2006
49 Parity Spawning occur only once or twice in the life cycle of most fish although exceptional famesl may spawn 3 times [spawning occur at intervals of 2-3 years] No category Coad, 2006
49 Parity Live up to 20 years No category Maitland, 1977
50 Parental care Nonguarders No care Fishbase, 2006