Trait completeness | 84% |
Total data | 160 |
References | 34 |
Author: Fabrice Téletchéa
License: All rights reserved
Trait id | Trait | Primary data | Secondary Data | References |
---|---|---|---|---|
4 | Egg adhesiveness | Not sticky | Non-Adhesive | Palstra, 2005 |
4 | Egg adhesiveness | Not sticky | Non-Adhesive | Fishbase, 2006 |
4 | Egg adhesiveness | Non-sticky | Non-Adhesive | Vincent, 2005 |
5 | Incubation time | 2-3.3 [Mass hatching occured after 50-80 hours, being completed after 70-110 hours] | 2.65 days | Prokhorchik, 1988 |
5 | Incubation time | 2-4.5 (mean 2.5) | 3.25 days | Lecompte-finiger, 1994 |
5 | Incubation time | "2-5 [Mass hatching after about 50-60h, range 47-120 [5 days at 20, but ""the surviving embryos had a delayed hatch on day 5 after fertilisation""]" | 3.5 days | Pedersen, 2003 |
5 | Incubation time | 2 [48 hour] | 2.0 days | Pedersen, 2004 |
7 | Degree-days for incubation | Certainly about 40-50 | 45.0 °C * day | Pedersen, 2003 |
7 | Degree-days for incubation | About 40 | 40.0 °C * day | Pedersen, 2004 |
6 | Temperature for incubation | Incubated at 21-23°C | 22.0 °C | Boetius and Boetius, 1980 |
6 | Temperature for incubation | 20 | 20.0 °C | Pedersen, 2003 |
6 | Temperature for incubation | 20 | 20.0 °C | Palstra, 2005 |
6 | Temperature for incubation | 20-21 | 20.5 °C | Pedersen, 2004 |
6 | Temperature for incubation | Incubated at 23°C | 23.0 °C | Amin, 1998 |
2 | Egg size after water-hardening | 2.3-2.9 [Swollen eggs] | 2.6 mm | Deelder, 1970 |
2 | Egg size after water-hardening | Eel eggs during further development will swell to diameters of 2.3 to 2.9 mm | 2.3 mm | Boetius and Boetius, 1980 |
2 | Egg size after water-hardening | Swelling of the eggs completes after 1.5 hour, the diameter of swollen eggs is 1.1-1.2 mm | 1.15 mm | Prokhorchik, 1988 |
2 | Egg size after water-hardening | About 2 mm after fertilization | 2.0 mm | Bruslé and Quignard, 2001 |
3 | Egg Buoyancy | Pelagic | Pelagic | Deelder, 1970 |
3 | Egg Buoyancy | In sea water of 31 °/oo all eggs sink | Semi-Pelagic | Boetius and Boetius, 1980 |
3 | Egg Buoyancy | Under experimental conditions, the fertilized eggs rose toward the surface in a salinity of 35%o [The large fat drop ensures egg buyoancy] | No category | Prokhorchik, 1988 |
3 | Egg Buoyancy | Newly fertilized eggs were at or near the surface | No category | Pedersen, 2003 |
3 | Egg Buoyancy | More than 90% of the eggs from all different batches floated | Pelagic | Palstra, 2005 |
3 | Egg Buoyancy | Pelagic | Pelagic | Coad, 2005 |
3 | Egg Buoyancy | Buoyant (Pelagic) | Pelagic | Fishbase, 2006 |
3 | Egg Buoyancy | Pelagic eggs | Pelagic | Vincent, 2005 |
1 | Oocyte diameter | 1.2 | 1.2 mm | Deelder, 1970 |
1 | Oocyte diameter | Eggs diameters are relatively uniform 1.05 ± 0.15 [Some discrepancy exists between different authors as to size of the European eel egg: 0.93-1.4, 1.0-1.1, 1.2-1.6, 0.9-1.1.3 mm] | 1.05 mm | Boetius and Boetius, 1980 |
1 | Oocyte diameter | Eggs of 1.0-1.3 mm in diameter have been considered to be fully ripened | 1.15 mm | Epler, 1981 |
1 | Oocyte diameter | Average diameter: 1.15 | 1.15 mm | Bruslé and Quignard, 2001 |
1 | Oocyte diameter | 1.1-1.2 [Seems to be fertilized eggs] | 1.15 mm | Bonislawska, 2001 |
1 | Oocyte diameter | 1-1.4 [Unfertilized eggs] | 1.2 mm | Pedersen, 2003 |
1 | Oocyte diameter | 0.829-0.924 [Ovulated egg] | 0.8765 mm | Pedersen, 2004 |
1 | Oocyte diameter | 0.8-0.95 [Stripped oocytes] | 0.875 mm | Palstra, 2005 |
1 | Oocyte diameter | Transparent ripe eggs with average diameter of 1.2 ± 0.06 | 1.2 mm | Amin, 1998 |
1 | Oocyte diameter | Mode 1.14, range 0.9-1.38 | 1.14 mm | Fishbase, 2006 |
1 | Oocyte diameter | 1.2 | 1.2 mm | Coad, 2005 |
Trait id | Trait | Primary Data | Secondary Data | References |
---|---|---|---|---|
11 | Temperature during larval development | About 20 | 20.0 °C | Deelder, 1970 |
11 | Temperature during larval development | The smallest (probably just hatched) larvae were found at depths between 50 and 300 m with temperatures of 18-24°C respectively | 21.0 °C | Vincent, 2005 |
12 | Sibling intracohort cannibalism | Present | Present | Hecht and Pienaar, 1993 |
12 | Sibling intracohort cannibalism | A RELIRE :!!! | Absent | Degani and Levanon, 1983 |
13 | Full yolk-sac resorption | After four days, the yok sac is almost completely resorbed, the fat doplet begins to resorb | No data | Prokhorchik, 1987 |
8 | Initial larval size | The prolarvae are 2.5-2.7 mm in the period of mass hatching | 2.6 mm | Prokhorchik, 1987 |
8 | Initial larval size | 2.7 | 2.7 mm | Prokhorchik, 1988 |
8 | Initial larval size | 2.5-2.7 | 2.6 mm | Lecompte-finiger, 1994 |
8 | Initial larval size | 2.9 | 2.9 mm | Bruslé and Quignard, 2001 |
9 | Larvae behaviour | Pelagic | Pelagic | Spilmann, 1961 |
9 | Larvae behaviour | Pelagic | Pelagic | Deelder, 1970 |
9 | Larvae behaviour | The prolarvae on hatching settled at the bottom of the incubation containers and remained lying with the back down, periodically making spiral movements and rising into the water column. The large fat droplet, broad fin border and head sinus ensured buoyancy of the prolarvae | Demersal | Prokhorchik, 1987 |
9 | Larvae behaviour | Pelagic | Pelagic | Bruslé and Quignard, 2001 |
Trait id | Trait | Primary Data | Secondary Data | References |
---|---|---|---|---|
18 | Female sexual dimorphism | Females are larger than males | Absent | Vollestad and Jonsson, 1986 |
24 | Maximum GSI value | Maximum GSI obtained in different studies: 12.6 only, 40 in other previous experiment and 60.7. | 12.6 percent | Boetius and Boetius, 1980 |
24 | Maximum GSI value | Reach 43.8-57.9 before spawning | 50.85 percent | Bezdenezhinykh and Petukhov, 1982 |
24 | Maximum GSI value | About 50% in artificial conditions | 50.0 percent | Vollestad and Jonsson, 1986 |
24 | Maximum GSI value | Up to 32 to 60% in artificial conditions ! | 32.0 percent | Bruslé and Quignard, 2001 |
24 | Maximum GSI value | 31.8 in artificial conditions | 31.8 percent | Pedersen, 2003 |
24 | Maximum GSI value | GSI of 44.8 ± 6.5 (range 36.3-60.0) in artificial conditions | 44.8 percent | Palstra, 2005 |
24 | Maximum GSI value | GSI of 68.4% | 68.4 percent | Amin, 1998 |
24 | Maximum GSI value | GSI equalled from 35.1 to 42.3 | 35.1 percent | Epler, 1981 |
25 | Oogenesis duration | Under artificial conditions, maturation of females took 5-6 months | 5.5 months | Pedersen, 2003 |
19 | Relative fecundity | 3000 | 3000.0 thousand eggs/kg | Deelder, 1970 |
19 | Relative fecundity | The data in the present paper can be converted to average 1.6 million/kg, which is about half of the Russian figure | 1.6 thousand eggs/kg | Boetius and Boetius, 1980 |
19 | Relative fecundity | 700-2600 up to 3000 | 1650.0 thousand eggs/kg | Bruslé and Quignard, 2001 |
19 | Relative fecundity | 3000 | 3000.0 thousand eggs/kg | Coad, 2005 |
27 | Age at sexual maturity | 8-15 | 11.5 years | Spillmann, 1961 |
27 | Age at sexual maturity | 5 [France], 9-13 [Germany], male | 11.0 years | Fishbase, 2006 |
27 | Age at sexual maturity | 2.5-5 [Male] | 3.75 years | Bruslé and Quignard, 2001 |
27 | Age at sexual maturity | Mean age about 5, range 2.5-9.1, means in various locations | 5.8 years | Vollestad and Jonsson, 1986 |
27 | Age at sexual maturity | Males tend to mature at and age of 3-4 years | 3.5 years | Vincent, 2005 |
26 | Resting period | About 0.6 ± 0.28 for the yellow stage and 1.78 ± for the silver stage | 0.6 months | Acou, 2003 |
26 | Resting period | > 1.4% for the silver stage | 1.4 months | Marchelidon, 1999 |
22 | Onset of oogenesis | Only after the fish begin their migration does further growth and development of gonads and oocytes take place, GSI at about 1.0-1.6 | No data | Bezdenezhinykh and Petukhov, 1982 |
21 | Oocyte development | Synchronous | Synchronous | Rinchard, 1996 |
20 | Absolute fecundity | The estimated fecundity of matured eels ranged from 0.7 to 2.6 million eggs [For immature eel the US authors give records of European specimens having 5-10 millions eggs on average with 15-20 million for the largest specimens] | 7.5 thousand eggs | Boetius and Boetius, 1980 |
20 | Absolute fecundity | Up to 4 000 | 4.0 thousand eggs | Palstra, 2005 |
20 | Absolute fecundity | The absolute fecundity amounted 1.48 millions eggs | 1.48 thousand eggs | Amin, 1998 |
17 | Weight at sexual maturity | Body weight of eels at catch averaged 0.8 Kg (range 0.5 to 1.5 kg) | 0.8 kg | Boetius and Boetius, 1980 |
17 | Weight at sexual maturity | Mean 0.425, range 0.130-2.105 [Female, n=1145] | 1.1175 kg | Vollestad and Jonsson, 1986 |
17 | Weight at sexual maturity | Mean of 0.343-1.242, in various areas | 0.7925 kg | Svedäng, 1996 |
17 | Weight at sexual maturity | Female silver: mean 0.58 ± 0.03, range 30.9-83.0 | 0.58 kg | Beullens, 1997 |
16 | Length at sexual maturity | 40-100 | 70.0 cm | Spillmann, 1961 |
16 | Length at sexual maturity | > 45 [Female] | 45.0 cm | Deelder, 1970 |
16 | Length at sexual maturity | Gonadal sex differentiation in the >European eel is ot age dependent but seems to be partly correlated with body length and begins when the eels reach 14-35 cm in length | 24.5 cm | Bieniarz, 1981 |
16 | Length at sexual maturity | Mean 61, range 39.0-105 [Female, n=1145] | 72.0 cm | Vollestad and Jonsson, 1986 |
16 | Length at sexual maturity | Means of 60.2-86.8, in various areas | 73.5 cm | Svedäng, 1996 |
16 | Length at sexual maturity | Female silver: mean 63.10 ± 1.22, range 53.10-79.50 | 63.1 cm | Beullens, 1997 |
16 | Length at sexual maturity | 45-50 [Female] | 47.5 cm | Bruslé and Quignard, 2001 |
16 | Length at sexual maturity | Metamorphosis occured between 40-75 cm | 57.5 cm | Acou, 2003 |
16 | Length at sexual maturity | Usually begin to mature at 54 cm to longer [38-130, silver age, female] | 84.0 cm | Coad, 2005 |
16 | Length at sexual maturity | 60 [Unsexed] | 60.0 cm | Fishbase, 2006 |
16 | Length at sexual maturity | Females mature at a size of > 60 cm | 60.0 cm | Vincent, 2005 |
15 | Age at sexual maturity | 10-18 | 14.0 year | Spillmann, 1961 |
15 | Age at sexual maturity | Mean age about 7, range 3.4-12.3, means in various locations | 7.85 year | Vollestad and Jonsson, 1986 |
15 | Age at sexual maturity | 12-18, means in different areas | 15.0 year | Svedäng, 1996 |
15 | Age at sexual maturity | 3-12 [Female] | 7.5 year | Bruslé and Quignard, 2001 |
15 | Age at sexual maturity | 8-9 [France], 15-18 [Germany], female | 8.5 year | Fishbase, 2006 |
15 | Age at sexual maturity | Age at maturity is highly variable, ranging from 6 to 50 years in females over a latitudinal gradient. In Northern Europe the mean age at maturity of females can range from 12 to 20 years (or older), while in Southern Europe it is 6-8 years | 7.0 year | Vincent, 2005 |
Trait id | Trait | Primary Data | Secondary Data | References |
---|---|---|---|---|
33 | Maximum GSI value | Gonad weight of mature males only constitutes, at most 14% of the body weight | 14.0 percent | Vollestad and Jonsson, 1986 |
33 | Maximum GSI value | 9.0 ± 1.10% coincide with the onset of spawning migration (treated males) | 9.0 percent | Amin, 1998 |
35 | Resting period | <2.5 | 2.5 months | NO REFERENCE |
35 | Resting period | About 0.1 for the silver stage | 0.1 months | Marchelidon, 1999 |
28 | Length at sexual maturity | 20-50 | 35.0 cm | Spillmann, 1961 |
28 | Length at sexual maturity | 29-40 [Silver age] | 34.5 cm | Coad, 2005 |
28 | Length at sexual maturity | 60 [Unsexed] | 60.0 cm | Fishbase, 2006 |
28 | Length at sexual maturity | < 45 [Male] | 45.0 cm | Deelder, 1970 |
28 | Length at sexual maturity | 30-45 [Male] | 37.5 cm | Bruslé and Quignard, 2001 |
28 | Length at sexual maturity | Mean 41, range 32.5-45 [Female, n=75] | 38.75 cm | Vollestad and Jonsson, 1986 |
28 | Length at sexual maturity | On average less than 45-50 cm | 47.5 cm | Colombo and Grandi, 1996 |
28 | Length at sexual maturity | Male silver: mean 42.03 ± 0.29, range 35.10-58.20 | 42.03 cm | Beullens, 1997 |
28 | Length at sexual maturity | Male silver eels about 38 cm were brought to the laboratory | 38.0 cm | Boetius and Boetius, 1980 |
28 | Length at sexual maturity | Males tend to mature at a size of around 40 cm | 40.0 cm | Vincent, 2005 |
29 | Weight at sexual maturity | Mean 0.107, range 0.028-0.162 [Female, n=75] | 0.095 kg | Vollestad and Jonsson, 1986 |
29 | Weight at sexual maturity | Male silver: mean 0.168 ± 0.004, range 0.077-0.409 | 0.168 kg | Beullens, 1997 |
29 | Weight at sexual maturity | Male silver eels about 80 g were brought to the laboratory | 80.0 kg | Boetius and Boetius, 1980 |
Trait id | Trait | Primary Data | Secondary Data | References |
---|---|---|---|---|
47 | Mating system | Under articificial conditions, eels are promiscuous | Promiscuity | Coad, 2005 |
47 | Mating system | In articificial conditions, apparently promiscuous | Promiscuity | Deelder, 1970 |
47 | Mating system | The number of participating males was 1-3 per female. During the first 15 minutes or so the male will swim around as if he were searching for someting while the female will remain almost quiet. When finally the male has detected the female he starts rubbing her belly with his head. He is especially attracted by her abdominal apertures. The female is thereby pushed slowly forwards through the water and starts a slow swimming. Still while the couple is moving, the stimulated male will try to obtain maximum contact between the bodies and is often seen to cling on the female with his back against her belly. When two or three males were placed together with one female they all tok part in the initial courtship. In every case, however, only one of the participating males released sperm during the experiment | No category | Boetius and Boetius, 1980 |
47 | Mating system | Mating began with the males which gently touched the females very often, followed by moving together with bodies in contact near the surface | No category | Amin, 1998 |
46 | Nycthemeral period of oviposition | Only a few of our eels were direclty observed to spawn a significant amount of eggs. But no doubt several other eels at intervals (especially by night) have releaseed small amount of eggs | Night | Boetius and Boetius, 1980 |
50 | Parental care | Nonguarders | No care | Fishbase, 2006 |
50 | Parental care | The parents showed absence of parental care so their behaviour can be classified as non-guarding | No care | Vincent, 2005 |
44 | Spawning substrate | Pelagophilous | Pelagophils | Balon, 1975 |
44 | Spawning substrate | Pelagophilous | Pelagophils | Boëtius and Boëtius, 1980 |
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 | Balon, 1975 |
41 | Spawning temperature | 17 | 17.0 °C | Coad, 2005 |
41 | Spawning temperature | About 20 | 20.0 °C | Deelder, 1970 |
41 | Spawning temperature | 16-17 | 16.5 °C | Bruslé and Quignard, 2001 |
41 | Spawning temperature | Water temperature ranged from 20 to 24°C | 20.0 °C | Amin, 1998 |
41 | Spawning temperature | Releasing hormone treated mature female adults tagged with radio transmitters in the Sargasso Sea demonstrated a preference for the upper zone of the ocean at depths of 18.7-18.8°C | 18.75 °C | Vincent, 2005 |
40 | Spawning period duration | Lengthly spawning season | No data | Wang and Tzeng, 2000 |
40 | Spawning period duration | Reproduction from February to April or March to July | No data | Bruslé and Quignard, 2001 |
42 | Spawning water type | Sargasso Sea | No category | Deelder, 1970 |
42 | Spawning water type | Sargasso Sea [Larvae hatch in region with low current] | Flowing or turbulent water | Bruslé and Quignard, 2001 |
42 | Spawning water type | Sargasso sea | No category | Vollestad and Jonsson, 1986 |
42 | Spawning water type | Fish spawning out of the tributary area: carp, pikeperch, catfish Silurus glanis and eel | No category | Hladik and Kubecka, 2003 |
43 | Spawning depth | Spawning grounds are about 400 meters | 400.0 m | Coad, 2005 |
43 | Spawning depth | Around 100-200 m deep | 150.0 m | Deelder, 1970 |
43 | Spawning depth | Spawning probably occurs at great depths | No data | Vollestad and Jonsson, 1986 |
43 | Spawning depth | Releasing hormone treated mature female adults tagged with radio transmitters in the Sargasso Sea demonstrated a preference for the upper zone of the ocean at depths of 250-270 m | 260.0 m | Vincent, 2005 |
36 | Spawning migration distance | Distance of 5000-6000 km is covered by mature adult | 5500.0 km | Fishbase, 2006 |
36 | Spawning migration distance | Spawning phase to reach the Sargasso Sea 7000 km from Europe | 7000.0 km | Coad, 2005 |
36 | Spawning migration distance | 6000-8000 km | 7000.0 km | Bruslé and Quignard, 2001 |
37 | Spawning migration period | In France in fall: October to December | ['October', 'December'] | Bruslé and Quignard, 2001 |
37 | Spawning migration period | Spawning migration that extend from November to February | ['February', 'November'] | Amin, 1998 |
37 | Spawning migration period | The mature silver eel leaves the rivers of Europe and North Africa in the autumn and swims accross the North Atlantic Ocean (navigating by an unknown process) to spawn in the Sargasso sea in the first half of the following year. Although the spawning process has never been observed, the small eel larvae (leptocephali) appear in the Sargasso Sea between February and July and drift on the ocean currents | ['December', 'July', 'February', 'October', 'November'] | Keetle and Haines, 2006 |
39 | Spawning season | January-July | ['April', 'March', 'January', 'May', 'June', 'July', 'February'] | McCleave, 1987 |
39 | Spawning season | March until May [Also January-February] | ['February', 'March', 'January', 'May'] | Fishbase, 2006 |
39 | Spawning season | Spawning takes place at the beginning of March | ['March'] | Coad, 2005 |
39 | Spawning season | During winter | ['February', 'March', 'January'] | Deelder, 1970 |
39 | Spawning season | November-July, peaking in January | ['November', 'January', 'July'] | Wang and Tzeng, 2000 |
39 | Spawning season | Based on all these observations, we now know that the European eel spawn primarily from March to June within a narrow ellipse whose long axis extends east-west from approximately 48° to 74°W longitude between 23° and 30° N latitude | ['March', 'June'] | Vincent, 2005 |
48 | Spawning release | Total spawner, only once | Total | Rinchard, 1996 |
48 | Spawning release | It seems that female eel undergoing artificial maturation function as batch spawners | Mutliple | Pedersen, 2003 |
48 | Spawning release | Each female probably spawns intermittently with several males each time | Ambiguous | Vollestad and Jonsson, 1986 |
48 | Spawning release | Most eels ovulated more than once over periods up to several days | Mutliple | Palstra, 2005 |
49 | Parity | Semelparous | Semelparous | Rinchard, 1996 |
49 | Parity | Mirgating to sea to spawn and die | Semelparous | Coad, 2005 |
49 | Parity | Spawing once and die | Semelparous | Palstra, 2005 |
49 | Parity | Spawn and then die | Semelparous | Vincent, 2005 |