Gymnocephalus cernuus

  • Scientific name
  • Gymnocephalus cernuus (Linnaeus, 1758)

  • Common name
  • Ruffe

  • Family
  • Percidae

  • External links
  • Fishbase
Trait completeness 84%
Total data195
References25
Image of Gymnocephalus cernuus

Author: Fabrice Téletchéa
License: All rights reserved

Traits detail



Egg (100%)


Trait id Trait Primary data Secondary Data References
4 Egg adhesiveness Adhesive, sticking to stones or submerged vegetation Adhesive Craig, 2000
4 Egg adhesiveness Upon contact with water, eggs become adhesive and will attach to various substrates Adhesive Crosier, 2005
4 Egg adhesiveness Ruffle eggs become adhesive upon contact with water and stick to substrate Adhesive Ogle, 1998
4 Egg adhesiveness Sticky Adhesive Spillmann, 1961
4 Egg adhesiveness Very adhesive Adhesive Kovac, 1998
4 Egg adhesiveness Sticky, in a gelly matrix Adhesive Fishbase, 2006
4 Egg adhesiveness Adhesive Adhesive Mann, 1996
5 Incubation time 5-12 [At 10-15°C] 8.5 days Ogle, 1998
5 Incubation time 5-12 [At 10-15°C] 8.5 days Crosier, 2005
5 Incubation time About 10 10.0 days Spillmann, 1961
5 Incubation time 8-10 [at 10-15°C] 9.0 days Craig, 2000
5 Incubation time [First hatching at 123 hours and 50% left the egg shells 4 hour later, the last larvae hatched within additional 5 hour in their experiment, others give: from 4.5 at 15-16°C to 27-29 at 6°C] 15.5 days Bonislawska, 2004
5 Incubation time 8-12 10.0 days Maitland, 1977
5 Incubation time 5-6 [At 16°C] 5.5 days Brown, 1998
7 Degree-days for incubation 130-150 140.0 °C * day Bruslé and Quignard, 2001
7 Degree-days for incubation 100-120 [5-12 at 10-15°C] 110.0 °C * day Crosier, 2005
7 Degree-days for incubation 100-120 [8-10 at 10-15°C] 110.0 °C * day Craig, 2000
7 Degree-days for incubation About 90 [5-6 days at 16°C] 5.5 °C * day Brown, 1998
7 Degree-days for incubation 136 136.0 °C * day Kovac, 1998
7 Degree-days for incubation [From 1962 to 2032 degree hour, 50% at 2032, others give 67.5 to 174] 1997.0 °C * day Bonislawska, 2004
6 Temperature for incubation "15 is the optima temperature for ""early development"" [Lower TL50 = 10, Upper TL50 = 21.5]" 15.0 °C Ogle, 1998
6 Temperature for incubation 12-13 12.5 °C Bruslé and Quignard, 2001
6 Temperature for incubation 10-15 12.5 °C Crosier, 2005
6 Temperature for incubation Optimal 15, range 9-21 15.0 °C Saat and Veersalu, 1996
6 Temperature for incubation Optimal range is 16-18°C [Temperature tested in other studies from 6 to 22°C] 17.0 °C Bonislawska, 2004
6 Temperature for incubation 16°C 16.0 °C Brown, 1998
6 Temperature for incubation Two incubation temperature at 12 ±0.2°C and 14 ± 2°C 12.0 °C Vetemaa and Saat, 1996
6 Temperature for incubation The dishes were kept under the same conditions under natural photoperiod at 16°C 16.0 °C Albert, 2006
2 Egg size after water-hardening 0.97-1.07 [Activated egg] 1.02 mm Kovac, 1998
2 Egg size after water-hardening The egg diameter was measured in the middle of the spawning season: 0.65-0.85 [In lake Peipsi], 0.9-1.1 [In Matsalu Bay], 0.95-1.25 |In Pärnu Bay] 0.75 mm Albert, 2006
3 Egg Buoyancy Demersal Demersal Bruslé and Quignard, 2001
3 Egg Buoyancy On the bottom demersal No category Fishbase, 2006
1 Oocyte diameter 0.34-1.3 (first batch : 0.90-1.21 and second batch 0.36-0.47) 0.82 mm Ogle, 1998
1 Oocyte diameter 1 1.0 mm Bruslé and Quignard, 2001
1 Oocyte diameter 0.34-1.33 [Eggs from first batch are larger 0.90-1.21, and second batch are smaller 0.36-0.47 mm] 0.835 mm Crosier, 2005
1 Oocyte diameter 1 1.0 mm Spillmann, 1961
1 Oocyte diameter Average is 1 1.0 mm Craig, 2000
1 Oocyte diameter 0.9-1.2 1.05 mm Crivelli and Rosecchi, 2001
1 Oocyte diameter 0.5-1 0.75 mm Fishbase, 2006
1 Oocyte diameter 0.86-1.0 [End of hydratation process, unfertilized egg] 0.93 mm Bonislawska, 2004
1 Oocyte diameter The maximum diameter reaching 0.98 (in ova). Other described as 1.03 (range0.90-1.21) 1.055 mm Neja, 1988
1 Oocyte diameter Immediatly before spawning the maturing oocyte diameters varied between 0.650 and 0.850 mm 0.65 mm Luksiene, 2000

Larvae (86%)


Trait id Trait Primary Data Secondary Data References
11 Temperature during larval development 25-30 optimal temperature for larval growth, larval survival is poor below 10°C [Possibly between 7.0°C to 24.8°C] 27.5 °C Ogle, 1998
11 Temperature during larval development 25-30 optimal temperature for larval growth 27.5 °C Craig, 2000
11 Temperature during larval development At water temperature ranging from 16.2 to 23.2°C (mean 19.4°C), the larval period lasted 20 days 16.2 °C Kovac, 1998
11 Temperature during larval development Larvae were captured at Allouez Bay from 30 May to 10 July, with peak catch the week of 13 June, corresponds to a temperature of 12-17°C on the graph. Larvae were captured at whaleback from 23 May to 3 June with a peak catch the week of 30 May, which corresponds to 12-16°c on the graph 14.5 °C Brown, 1998
10 Reaction to light Positively phototactic, little or no pelagic stage Photopositive Ogle, 1998
10 Reaction to light Larvae are intially photophobic Photophobic Mann, 1996
13 Full yolk-sac resorption Active feeding and swimming occur within one week of hatching after the yolk-sac is absorbed No data Crosier, 2005
14 Onset of exogeneous feeding Feeding begins after about 1 week 1.0 °C * day Crosier, 2005
14 Onset of exogeneous feeding The transition to exogenous feeding takes plance in benthopelagic layer about 1 week after hatching 1.0 °C * day Ogle, 1998
14 Onset of exogeneous feeding 120-130: Active feeding and swim-up occurring 13 days after fertilization (hatching 5-6 days after fertilization) at 16°C 125.0 °C * day Brown, 1998
8 Initial larval size 3.5-4.4 3.95 mm Ogle, 1998
8 Initial larval size 3 3.0 mm Bruslé and Quignard, 2001
8 Initial larval size 3.5-4.4 3.95 mm Crosier, 2005
8 Initial larval size 3 3.0 mm Spillmann, 1961
8 Initial larval size 2.5-3.2 2.85 mm Craig, 2000
8 Initial larval size 3.35-3.81 3.58 mm Kovac, 1998
8 Initial larval size 3.85 ± 0.08 [Other give 3.52 to 4.29] 3.85 mm Bonislawska, 2004
8 Initial larval size Standard length of larvae of freswater : meanSL range from 2.05 and 2.23 and brackishwater range from 2.32-3.03 2.675 mm Albert, 2006
9 Larvae behaviour Embryo remains sedentary on the bottom for 3 to 7 days until reaching a size of 4.5-5.0 Demersal Ogle, 1998
9 Larvae behaviour Remain sedentary for 3-7 days Demersal Crosier, 2005
9 Larvae behaviour Most to the time they stay at the bottom Demersal Kovac, 1998
9 Larvae behaviour Immediate dispersion after hatching Demersal Urho, 2002
9 Larvae behaviour The larvae easily stayed in the water column and were fully prepapred for independent living in external environment Demersal Bonislawska, 2004
9 Larvae behaviour Larval ruffe hatch and become pelagic within 1 to 2 weeks after egg deposition and could possibly be netrained in ballast water duting the pelagic period Pelagic Brown, 1998

Female (83%)


Trait id Trait Primary Data Secondary Data References
24 Maximum GSI value 7.1-15.6 [Average spawning GSI] 11.35 percent Ogle, 1998
24 Maximum GSI value 9-11 [May] 10.0 percent Brown, 1998
24 Maximum GSI value 8-11 [April] 9.5 percent Leino and McCormick, 1997
24 Maximum GSI value Gonad in stage VI, meaN: 13.81, range 9.52-24.29 [In other study, the coefficient in females migrating to spawn to average 15.6 (9.0-22.0)] 16.905 percent Neja, 1988
19 Relative fecundity 352-1540 946.0 thousand eggs/kg Ogle, 1998
19 Relative fecundity 585-1540 1062.5 thousand eggs/kg Kovac, 1998
19 Relative fecundity 305-1540 922.5 thousand eggs/kg Crivelli and Rosecchi, 2001
19 Relative fecundity Mean 1066.3, range 585-1540 eggs/g 1062.5 thousand eggs/kg Neja, 1988
27 Age at sexual maturity 2-3 but sometimes 1 [Sex not specified] 2.5 years Ogle, 1998
27 Age at sexual maturity 2 [ sex not specified] 2.0 years Bruslé and Quignard, 2001
27 Age at sexual maturity 2 [Part of the population at 1] 2.0 years Kovac, 1998
27 Age at sexual maturity 1-3 [Sex not specified] 2.0 years Crivelli and Rosecchi, 2001
27 Age at sexual maturity 1 [Male] 1.0 years Fishbase, 2006
27 Age at sexual maturity 2 [Not specified] 2.0 years Environment agency, 1996
26 Resting period 2-3 [June, July and August] 2.5 months Leino and McCormick, 1997
22 Onset of oogenesis Oocytes mature in 165 days in winter and 30 days during summer ['March', 'January', 'September', 'August', 'July', 'February'] Ogle, 1998
22 Onset of oogenesis Between September and March, gonad weight increases slowly ['March', 'September'] Kovac, 1998
22 Onset of oogenesis September slight increase ['September'] Leino and McCormick, 1997
22 Onset of oogenesis In September, most females (64.1%) had ovaries at stage 2. No stage 4 gonads were found at that time ['September'] Neja, 1988
23 Intensifying oogenesis activity March-April ['April', 'March'] Leino and McCormick, 1997
21 Oocyte development Group- synchronous, multiple clutches [ovaries may contain several oocytes stages simultaneously] Synchronous Leino and McCormick, 1997
21 Oocyte development Polycyclic, with asynchrous ripening of eggs and protracted spawning Asynchronous Kovac, 1998
21 Oocyte development A mature ruffe ovary contains three types of eggs: 1) small, hyaline, and clorless, 2) larger, opaque, white and orange in color, and 3) large, partly hyaline, and yellow-orange and ornage in color. Only the latter two types will be released during the next spawing season No category Ogle, 1998
21 Oocyte development Asynchronous development Asynchronous Luksiene, 2000
20 Absolute fecundity 10-150 80.0 thousand eggs Crosier, 2005
20 Absolute fecundity 4-200 for the first batch and 0.352-6 for the second 102.0 thousand eggs Ogle, 1998
20 Absolute fecundity 40-1000 520.0 thousand eggs Bruslé and Quignard, 2001
20 Absolute fecundity 100-150 125.0 thousand eggs Spillmann, 1961
20 Absolute fecundity 17.8 is the average [13-82] 47.5 thousand eggs Craig, 2000
20 Absolute fecundity 4-100 52.0 thousand eggs Environment agency, 1996
20 Absolute fecundity 4-105 54.5 thousand eggs Maitland, 1977
20 Absolute fecundity 13.338-82.233 47.7855 thousand eggs Neja, 1988
17 Weight at sexual maturity 20-30 g ! [Different class studied strating at 11.0-20.9 g !] 25.0 kg Neja, 1988
16 Length at sexual maturity 11-12 [Sex not specified] 11.5 cm Ogle, 1998
16 Length at sexual maturity 11-12 [Sex not specified] but sometimes 6.5-7.0 11.5 cm Craig, 2000
16 Length at sexual maturity 5.7-9 SL [All female exceeding 9 cm were mature] 7.35 cm Kovac, 1998
16 Length at sexual maturity Described as 11-12, but also at 6.5-7.0 [sex not specified] 11.5 cm Neja, 1988
15 Age at sexual maturity 2-3 but sometimes 1 [Sex not specified] 2.5 year Ogle, 1998
15 Age at sexual maturity 2 [Sex not specified] 2.0 year Bruslé and Quignard, 2001
15 Age at sexual maturity 2 [Part of the population at 1] 2.0 year Kovac, 1998
15 Age at sexual maturity 1-3 [Sex not specified] 2.0 year Crivelli and Rosecchi, 2001
15 Age at sexual maturity 1-2 1.5 year Fishbase, 2006
15 Age at sexual maturity 2 [Not specified] 2.0 year Environment agency, 1996
15 Age at sexual maturity 2-3 [Not specified] 2.5 year Maitland, 1977
15 Age at sexual maturity All the individuals caught before spawning and belonging to age group 2 and older groups had their gonads at stage 4 or 5, that is they were ready to the nearest spawning. One may infer that some individuals spawn as early as at age 1+. In Poland, it marres at the end of its second year of life. In the river Nadym drainage, it matures at age 2 (usually hower, 3+ or 4+) 2.0 year Neja, 1988

Male (78%)


Trait id Trait Primary Data Secondary Data References
31 Onset of spermatogenesis Male gonadal activity occurs during spring and autumn ['April', 'May', 'December', 'June', 'October', 'November'] Crosier, 2005
31 Onset of spermatogenesis Two periods of gonad activity are observed in males in the course of the year, spring and autumn wves of spermatogenesis occur [Winter conditions provoke a considerable slowing down of spermatogenesis, ending in most specimens (81%) with its cessation in the phase of reprodcution of spermatogonia ['April', 'May', 'December', 'June', 'October', 'November'] Butskaya, 1981
31 Onset of spermatogenesis In September, male gonads were more advanced in development (23.5% and 76.5% at stage 2 and 3, respectively). No stage 4 gonads were found at that time ['September'] Neja, 1988
33 Maximum GSI value 7-10 [Average spawning male GSI] 8.5 percent Ogle, 1998
33 Maximum GSI value In 3 test fish, the coefficient of maturity was 3.74, 4.18 and 4.80 3.0 percent Butskaya, 1981
33 Maximum GSI value Male in VI stage, were on average 7.11, range 5.26-12.18 8.72 percent Neja, 1988
32 Main spermatogenesis activity The peak of the spring wave of spermatogenesis, is observed annually under natural conditions, in late May, when all phases of spermatogenesis, from the reprodcution of spermatogonia to the formationof new ripe spermatozoids, are found in cysts of the testes. ['April', 'May', 'June'] Butskaya, 1981
35 Resting period Periods in which gametogensis is absent occuring between spring and autumn [The coefficients of maturity after discharge of the spermatozoids (in the absence of spermatogensis) is on average 0.8% (range 0.5-1.2%), and after completion of the rearrangement of the somatic elements of the testes less than 0.25% 0.85 months Butskaya, 1981
28 Length at sexual maturity 11-12 [Sex not specified] 11.5 cm Ogle, 1998
28 Length at sexual maturity 11-12 [Sex not specified] but sometimes 65-70 11.5 cm Craig, 2000
28 Length at sexual maturity 3.2-8 SL [All male exceeding 8 cm were mature] 5.6 cm Kovac, 1998

Spawning conditions (80%)


Trait id Trait Primary Data Secondary Data References
50 Parental care Non-guarding No care Ogle, 1998
50 Parental care Non-guarders No care Fishbase, 2006
50 Parental care Non-guarders No care Mann, 1996
44 Spawning substrate Spawn on occurs on a variety of substrates : open-substrate, phytolithophil, submerged plants, logs, branches, or gravel or rocks but also hard bottoms, sand, clay, or gravel Ambiguous Ogle, 1998
44 Spawning substrate Ribbons are winded up aquatic plants Phytophils Bruslé and Quignard, 2001
44 Spawning substrate Submerged plants, logs, branches, rocks Ambiguous Crosier, 2005
44 Spawning substrate Stones and vegetation Ambiguous Craig, 2000
44 Spawning substrate Plants, or gravel Ambiguous Crivelli and Rosecchi, 2001
44 Spawning substrate Eggs adhere to sumerged plants, bit other substrata are utilised if suitable plants are absent, <5 cm in diameter Phytophils Mann, 1996
44 Spawning substrate Stones and weed Ambiguous Environment agency, 1996
44 Spawning substrate Phytolithophil Lithophils Wolter and Vilcinskas, 1997
44 Spawning substrate Phyto-lithophils Lithophils Balon, 1975
44 Spawning substrate Stones and plants Ambiguous Maitland, 1977
45 Spawning site preparation Eggs are deposited on plants or rocks Susbtrate chooser Billard, 1997
45 Spawning site preparation Open water/ substratum egg scatterers Open water/substratum scatter Fishbase, 2006
45 Spawning site preparation Open substratum spawner Open water/substratum scatter Mann, 1996
45 Spawning site preparation Open substratum spawner Open water/substratum scatter Balon, 1975
41 Spawning temperature 6-18 12.0 °C Ogle, 1998
41 Spawning temperature 5-18 [mainly between 12-14] 11.5 °C Brown, 1998
41 Spawning temperature 10-15 12.5 °C Bruslé and Quignard, 2001
41 Spawning temperature Spawning begins when temperature reach 6°C 6.0 °C Crosier, 2005
41 Spawning temperature 11.6-18.0 is the normal range but could start at 6-8 14.8 °C Craig, 2000
41 Spawning temperature 7.1-20.2 13.65 °C Kovac, 1998
41 Spawning temperature 12-18 15.0 °C Crivelli and Rosecchi, 2001
41 Spawning temperature 11.6-18 14.8 °C Saat and Veersalu, 1996
41 Spawning temperature 6-12 9.0 °C Mann, 1996
40 Spawning period duration 8 8.0 weeks Brown, 1998
40 Spawning period duration 8 8.0 weeks Leino and McCormick, 1997
40 Spawning period duration 7-8 7.5 weeks Terver, 1984
40 Spawning period duration Started spawning in early May, the spawning lasting no longer than until early June No data Neja, 1988
42 Spawning water type Where the current is fairly rapid Flowing or turbulent water Craig, 2000
42 Spawning water type Spawning of Eurasian ruffe in the the Baka side-arm system of the River Danube, in the Orava Reservoir, Lipno reservoir No category Kovac, 1998
43 Spawning depth Shallow water with aquatic macrophytes No data Craig, 2000
43 Spawning depth Shallow water No data Bruslé and Quignard, 2001
43 Spawning depth Often moves from deep to shallow areas to spawn No data Crosier, 2005
43 Spawning depth Shallow waters, usually less than 3 meters 3.0 m Ogle, 1998
43 Spawning depth Most spawning occurs at a depth of less than 1 m 1.0 m Leino and McCormick, 1997
43 Spawning depth Shallow water No data Environment agency, 1996
43 Spawning depth Shallow waters No data Maitland, 1977
36 Spawning migration distance Ruffe do not make long migrations, however short diurnal and seasonal movements are common No data Kovac, 1998
36 Spawning migration distance Limited home range No data Environment agency, 1996
37 Spawning migration period Undergoes spawning migrations from winter habitats which are deep areas in river or lakes to shallow areas which are stony and covered with aquatic macrophytes ['February', 'March', 'January'] Craig, 2000
39 Spawning season March to May ['March', 'May'] Spillmann, 1961
39 Spawning season May-July ['May', 'July', 'June'] Brown, 1998
39 Spawning season April-May but June in Nothern Region ['April', 'May', 'June'] Bruslé and Quignard, 2001
39 Spawning season Usually during April-July ['April', 'July'] Crosier, 2005
39 Spawning season Mid-April to July ['April', 'July'] Ogle, 1998
39 Spawning season April-June ['April', 'May', 'June'] Craig, 2000
39 Spawning season Mid-April to Mid-June ['April', 'June'] Kovac, 1998
39 Spawning season Late April to Mid-June ['April', 'June'] Leino and McCormick, 1997
39 Spawning season March to May ['March', 'May'] Billard, 1997
39 Spawning season March to August ['August', 'March'] Crivelli and Rosecchi, 2001
39 Spawning season April-May but also March to up to August ['April', 'August', 'March', 'May'] Fishbase, 2006
39 Spawning season March-July ['April', 'March', 'May', 'June', 'July'] Mann, 1996
39 Spawning season March-May ['April', 'March', 'May'] Environment agency, 1996
39 Spawning season March to early May ['March', 'May'] Terver, 1984
39 Spawning season April-May ['April', 'May'] Maitland, 1977
39 Spawning season In Polish waters typically from mid-April through end of May ['April', 'May'] Neja, 1988
48 Spawning release More than one clutches of eggs per spawning season, intermittent spawner Fractional Leino and McCormick, 1997
48 Spawning release Eggs are extruted in long adhesive and 'accordion folded' strands No category Billard, 1997
48 Spawning release Female spawn several batches during the spawning season Mutliple Crivelli and Rosecchi, 2001
48 Spawning release Intermittent spawner with prolonged spawning season Fractional Saat and Veersalu, 1996
48 Spawning release Eggs are extruted in long adhesive and 'accordion folded' strands like perch ??? No category Spillmann, 1961
48 Spawning release "Ruffle eggs are extruded in ""strands"" ? Never observed anywhere else" No category Ogle, 1998
48 Spawning release 1000-6000 by batch, in a form of a ribbon Mutliple Bruslé and Quignard, 2001
48 Spawning release Females may spawn two or more batches of eggs in a season, one in winter-spring and one later in summer. Spawnings occurs intermittently, with eggs being laid in two or more batches per year Ambiguous Crosier, 2005
48 Spawning release Intermittent spawners: eggs are laid in two or more batches Ambiguous Craig, 2000
48 Spawning release Spawing is prolonged and portional, the eggs being laid in two or three portions No category Neja, 1988
48 Spawning release The analysis indicated that an average ruffe in all heated areas produced three mature portions of eggs during the spawing season, compard with two in the reference area No category Luksiene, 2000
48 Spawning release In asynchronous spawners like ruffe, egg size in consecutive batches is found to be smaller, which is associated with the diminishing resources of the female Mutliple Albert, 2006
49 Parity Female ruffe may reach age 11, but male ruffe generally do not exceed age 7 No category Ogle, 1998
49 Parity The prolonged spawning period is possibly due to different rates of development of the ovaries among females of different ages No category Brown, 1998
49 Parity Most individuals atain a maximum age of 6 years, excepeionally 7 or 8 years No category Kovac, 1998