Life-History Strategies of Fishes Rainer Froese IfM-GEOMAR.
-
Upload
colin-austin -
Category
Documents
-
view
225 -
download
0
Transcript of Life-History Strategies of Fishes Rainer Froese IfM-GEOMAR.
Life-History Strategies of Fishes
Rainer Froese
IfM-GEOMAR
Content
• All data from FishBase
• Choice of key traits
• Combinations of traits
• Life history strategies and Phylogeny
• Exploring life-history space
• Testing evolutionary theories
• Success of life-history strategies
Classes of
Fishes
Phylogeny
Classes Orders
Families
Genera Species
Actinopterygii (ray-finned fishes)
45 467 4,573 27,271
Sarcopterygii (lobe-finned fishes)
3 4 4 11
Elasmobranchii (sharks and rays)
11 44 175 961
Holocephali (chimaeras) 1 3 6 37
Cephalaspidomorphi (lampreys)
1 2 9 42
Myxini (hagfishes) 1 1 7 66
Key Trait: Size
0
1000
2000
3000
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Length (log; cm)
Fre
qu
en
cy
small medium large very large
23,603 species
Size Distribution is Multi-ModalCumming and Havlicek (2002)
0
500
1000
1500
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Length (log; cm)
Fre
qu
en
cy
Key Trait: Trophic Level
0
500
1000
1500
2.0 2.5 3.0 3.5 4.0 4.5 5.0
Trophic level
Fre
qu
en
cy
7,161 species
herbi-vore
omnivore low-level predator mid-levelpredator
top-predator
Key Trait: Productivity(modified after Musick 1999)
Parameter High Medium Low Very low
rmax (1/year) > 0.5 0.16 – 0.50 0.05 – 0.15 < 0.05
td (years) <1.4 1.4 - 4.4 4.5 - 14 > 14
Interest rate (%) > 65 17 – 65 5 - 16 < 5
K (1/year) > 0.3 0.16 – 0.30 0.05 – 0.15 < 0.05
Fecundity (1/year) > 10,000 100 – 1000 10 – 100 < 10
tm (years) < 1 2 – 4 5 – 10 > 10
tmax (years) 1 – 3 4 – 10 11 – 30 > 30
Key Traits: Productivity
Productivity Species Percent
Very low 263 10.5
Low 1016 40.5
Medium 879 25.0
High 353 14.0
2,511 species
Productivity is a Proxy for Metabolism
10
100
1000
10000
1 High 2 Medium 3 Low 4 Very low
Productivity
Oxy
ge
n c
on
sum
ptio
n (
mg
/kg
/h)
Trait Correlation: Size vs Troph
1
10
100
1000
10000
1 Herb 2 Omni 3 Low 4 Mid 5 Top
Trophic groups
Le
ng
th (
cm)
Trait Correlation: Size vs Productivity
1
10
100
1000
10000
1 Very low 2 Low 3 Medium 4 High
Productivity groups
Le
ng
th (
cm)
Trait Correlation: Trophic Level vs Productivity
2.0
3.0
4.0
5.0
1 Very low 2 Low 3 Medium 4 High
Productivity groups
Tro
ph
ic le
vel
Phylogeny Limits Traits: Size
HagfishLampreys
ChimaerasSharks & rays
Lobe-finnedRay-finned
1
10
100
1000
10000
1 2 3 4 5 6
Classes
Le
ng
th (
cm)
small
medium
large
very large
Phylogeny Limits Traits: Troph
HagfishLampreys
ChimaerasSharks & rays
Lobe-finnedRay-finned
2.0
3.0
4.0
5.0
1 Myx 2 Cep 3 Hol 4 Ela 5 Sar 6 Act
Classes
Tro
ph
ic le
vel
Phylogeny Limits Traits: Productivity
Class Productivity Species Percent
Myxini Low 66 100
Cephalaspidomorphi Low 16 36
Medium 2 5
Holocephali Low 37 100
Elasmobranchii Very low 206 21
Low 528 55
Sarcopterygii Very low 10 91
Actinopterygii Very low 47 0.2
Low 369 1.4
Medium 877 3.2
High 353 1.3
Available Data are Biased
• Combined available data for 1,880 species are biased towards large, commercial, northern-hemisphere, temperate species
• Solution: Use modelling approach to expand data base
Expanding the Database: Trophic Level
2
2.5
3
3.5
4
4.5
5
1 10 100 1000
Length (cm)
Tro
ph
ic l
evel
Trophic level of 97 species of Genus Epinephelus as a function of their body length.
Top
Medium
Low
Residuals of Modelled Troph
0
500
1000
1500
2000
2500
-2 -1 0 1 2 3
Species (log; n)
Fre
qu
en
cy
Residual Troph
Expanding the Database: Productivity (K)
.01
.1
1
10
1 10 100 1000
Length (cm)
K (
1/y
ea
r)
Von Bertalanffy growth parameter K plotted over maximum length for Family Serranidae
High
Medium
Low
Very low
Modelled vs Observed K
0.0
0.1
1.0
10.0
0.01 0.10 1.00 10.00
K observed (1/year)
K p
red
icte
d (
1/y
ea
r)
Life-History Strategies
• The extended data set contains 20,480 species, nearing a census
• Bias towards large northern species has disappeared
• Of 80 possible combinations of traits only 50 are used
• Three strategies are used by 60% of the species
Occupation of Size-Troph Space
Small Medium LargeVerylarge
Herb
OmniLow
MidTop
0
2000
4000
6000
8000
10000
12000
Occupation of Size-Productivity Space
Small MediumLarge
Verylarge
Very low
Low
MediumHigh
0
2000
4000
6000
8000
10000
Occupation of Troph-Productivity Space
HerbOmni
LowMid
Top
Very low
Low
MediumHigh
0
2000
4000
6000
8000
10000
Testing of Evolutionary Theories
• Predictions of nine evolutionary theories (r-K, succession, temperature, area, etc) were tested
• 88-100% of the predictions were correct
• In case of conflicting predictions temperature theory usually prevailed over r-K and succession theories
Success of Life-History Strategies
• High abundance and wide distribution were taken as indicators of success
• Strategies associated with high abundance or small to medium range had highest species numbers
• Productivity of threatened fishes was significantly lower than that of non-threatened fishes
Thanks to the FishBase Team
Thanks to our Donors
Thank You
• Comments?
• Questions?
• Suggestions?