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 ClassesOrdersFamiliesGeneraSpecies Actinopterygii (ray-finned fishes)454674,57327,271 Sarcopterygii (lobe-finned fishes)34411 Elasmobranchii (sharks and rays) Holocephali (chimaeras)13637 Cephalaspidomorphi (lampreys)12942 Myxini (hagfishes)11766

Key Trait: Size smallmediumlargevery large 23,603 species

Size Distribution is Multi-Modal Cumming and Havlicek (2002)

Key Trait: Trophic Level 7,161 species herbi- vore omnivorelow-level predatormid-level predator top- predator

Key Trait: Productivity (modified after Musick 1999) ParameterHighMediumLowVery low r max (1/year)> – – 0.15< 0.05 t d (years)< > 14 Interest rate (%)> 6517 – < 5 K (1/year)> – – 0.15< 0.05 Fecundity (1/year)> 10, – – 100< 10 t m (years)< 12 – 45 – 10> 10 t max (years)1 – 34 – 1011 – 30> 30

Key Traits: Productivity ProductivitySpeciesPercent Very low Low Medium High ,511 species

Productivity is a Proxy for Metabolism

Trait Correlation: Size vs Troph

Trait Correlation: Size vs Productivity

Trait Correlation: Trophic Level vs Productivity

Phylogeny Limits Traits: Size Hagfish Lampreys Chimaeras Sharks & rays Lobe-finned Ray-finned small medium large very large

Phylogeny Limits Traits: Troph Hagfish Lampreys Chimaeras Sharks & rays Lobe-finned Ray-finned

Phylogeny Limits Traits: Productivity ClassProductivitySpeciesPercent MyxiniLow66100 CephalaspidomorphiLow1636 Medium25 HolocephaliLow37100 ElasmobranchiiVery low20621 Low52855 SarcopterygiiVery low1091 ActinopterygiiVery low470.2 Low Medium High3531.3

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 Trophic level of 97 species of Genus Epinephelus as a function of their body length. Top Medium Low

Residuals of Modelled Troph Residual Troph

Expanding the Database: Productivity (K) Von Bertalanffy growth parameter K plotted over maximum length for Family Serranidae High Medium Low Very low

Modelled vs Observed K

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

Occupation of Size-Productivity Space

Occupation of Troph-Productivity Space

Testing of Evolutionary Theories Predictions of nine evolutionary theories (r-K, succession, temperature, area, etc) were tested % 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

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