Transcript t max - FishBase

Biodiversity of Fishes
Understanding Longevity
Rainer Froese
09.01.2014
Longevity in Fish
• Maximum age on record for a species
• Maximum time available for growth and
reproduction
• Used as
– proxy for natural mortality M ~ 4.5/tmax
– 1 of 5 criteria to estimate resilience
Taylor (1958)
Longevity as age at 95% of L∞
ln( 1 
t L0 .9 5  
0 . 95 L 
L
K
)
 t0  
ln( 0 . 05 )
K
 t0 
2 . 996
K
Longevity (years) = 3 / K
where t is age, L∞ is the asymptotic body length, K indicates how fast L∞
is approached, and t0 is the hypothetical age at zero length.
Taylor, C.C., 1958, Cod growth and temperature., J. Cons. Int. Explor. Mer. 23:366-370.
Longevity vs Taylor’s 3/K
1000
Observed maximum age (years)
1:1
100
10
1
0.1
0.1
1
10
100
1000
Age at 95% L∞ (years)
353 species, FishBase 11/2006
Longevity vs Temperature
2.5
Observed longevity (log; years)
y = -0.0142x + 1.3505
R2 = 0.0702
2.0
1.5
1.0
0.5
0.0
-0.5
0
5
10
15
20
Mean annual temperature (degree Celsius)
25
30
Longevity vs Maximum Length
1000
Maximum age (years)
100
10
1
0.1
1
10
100
1000
Maximum length (cm)
Maximum age and length known for 1036 species of fishes, FishBase 11/2006
Maximum Length vs Longevity
Maximum length (cm)
1000
100
10
1
0.1
1
10
100
1000
Maximum age (years)
Maximum length and age known for 1036 species of fishes, FishBase 11/2006
(Slope = 0.80, 95% CL = 0.76-0.84, r2 = 0.6124)
L∞ vs tmax within Species
Asymptotic length (L∞ ; cm)
10000
1000
100
10
6410 growth studies
FishBase 11/2006
1
0.1
1
10
100
1000
Age at 95% L∞ (years)
Carcharhinus acronotus
Pleuronectes platessa
Stolephorus indicus
Median slope for populations within 141 species = 0.42 (95% CL = 0.39-0.46)
Longevity vs Age at Maturity
2.5
Observed longevity (log; years)
2.0
1.5
1.0
0.5
y = x + 0.61
R2 = 0.674
0.0
-0.5
-0.5
0.0
0.5
Age at maturity (log; years)
1.0
tmax ~ 4 * tm
1.5
Empirical Equations for Longevity
Equation Intercept
Nr
n
R2
C.V.
353
0.653
0.2093
353
0.371
0.2814
229
0.680
0.1726
353
0.070
0.3423
353
0.671
0.2039
229
0.752
0.1523
353
0.654
0.2084
229
0.707
0.1655
353
0.466
0.2597
229
0.760
0.1501
353
0.683
0.2005
0.5158
281
0.748
0.1488
0.5513
313
0.744
0.1517
log
log
log
3/K
Lmax
tm
1
0.1983
4
0.0252
5
0.6608
6
1.3505
7
0.0096
0.7455
8
0.3930
0.4163
9
0.2731
0.8434
10
0.3832
0.1893
11
0.2543
0.6371
12
0.2611
0.3740
0.1085
13
0.0980
0.6849
0.2195
14
0.2834
0.3411
0.1126
15
0.4136
0.4089
T
0.8608
0.6153
0.9277
-0.0142
0.1754
0.5593
-0.0035
0.7891
-0.0166
0.5173
-0.0063
Longevity vs Environment
L o n g e v ity (lo g ; y e a r)
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
Freshwater
Diadromous
Brackish
Environment
Marine
Longevity vs Habitat
L o n g e v ity (lo g ; y e a r)
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
Deep
Demersal
Pelagic
Habitat
Reef
Longevity vs Trophic Level
Observed longevity (log; years)
2.5
2
1.5
1
0.5
0
-0.5
1.5
2.5
3.5
Trophic level
4.5
Facts
• Relative size at maturity (Lm / Lmax)
– Fish 0.44 (n=530, 95% LCL =0.421, UCL=0.451)
– Marine mammals 0.76 (n=9, LCL=0.716, UCL=0.803)
– Birds 1.0
• Relative age at maturity (tm / tmax)
– Fish 0.24 (n=229, LCL=0.224, UCL=0.253)
– Marine mammals 0.13 (LCL= 0.0913, UCL = 0.198)
– Birds 0.05 (LCL=0.0364, UCL=0.0695)
Whale shark vs Fin whale
• The largest fish, the Whale shark (Rhincodon
typus) needs about 9 years to reach maturity at
about 5.5 m and 750 kg, and about 60 years to
reach a maximum length of 14 m and 12 tons.
• The fin whale (Balaenoptera physalus) needs
about 7 years to reach maturity at a size of
about 20 m and about 36 tons, with a maximum
size of about 25 m and 70 tons.
Whale shark vs Fin whale
2500
Fin whale
Length (cm)
2000
1500
1000
Whale shark
500
0
0
10
20
30
Age (years)
40
50
60
White shark vs Killer whale
• Great white shark females take about 12
years to reach maturity at 4.5-5 m and
about 0.8 tons; they need 36 years to
reach a maximum size of 7.2 m and 3.4
tons;
• Killer whales (Orcinus orca) reach maturity
in 6-10 years at 5-6 m length and about
1.8 tons, with the typical size of about 7 m
and 3.8 tons reached a few years later.
Great white shark vs Killer whale
800
Killer whale
700
600
Length (cm)
Great white shark
500
400
300
200
100
0
0
5
10
15
20
Age (years)
25
30
35
40
Conclusion
• Because of physics (e.g. gravity), organisms have a
‘bauplan’ optimized for a certain adult size; they
maximize their fitness if they reach that size as fast as
possible
• Fish growth is limited by the oxygen-temperature
window, and thus they need all their life to reach
maximum size
• Birds and mammals do not have this limitation (air
breathers with constant body temperature) and reach
maximum size early in life
• Gills suck, but they last: bowhead whales reach 130
years, cockatoos 60 years, humans 121 years, turtoise
180 years, fish (kois) > 200 years
Exercises
• Select one of these species:
–
–
–
–
Orange roughy (Hoplostethus atlanticus)
Beluga (Huso huso)
Anchoveta (Engraulis ringens)
Transparent goby (Aphia minuta)
• Discuss age (tmax, tm), habitat, food, growth,
reproduction, suitability to fishing
• Use the graphs in FishBase to make your point