The Research in Fish Base Rainer Froese If

The Research in Fish. Base Rainer Froese If. M-GEOMAR

Classes of Fishes

There are Six Classes of Fishes Classes Common Orders Families Genera ancestor (n) (n) (million y) Species (n, %) Myxini (hagfishes) 600 1 1 6 71 0. 2 Cephalaspidomorphi (lampreys) 450 1 1 9 42 0. 1 Holocephali (chimaeras) 420 1 3 6 38 0. 1 Elasmobranchii (sharks and rays) 420 11 45 175 975 3. 4 Sarcopterygii (lobe-finned fishes) 420 3 4 4 11 0. 04 Actinopterygii (ray-finned fishes) 400 45 470 4, 640 28, 363 96. 1 62 524 4, 840 29, 500 100 Total Source: Fish. Base 09/2006

Key Trait: Size small medium large very large 23, 603 species

What You Eat You Are (+1) Trophic level 4 Top predators 3 Prey fish 2 Zooplankton 1 Phytoplankton 10%. . *. . * *. *. *. . .

Key Trait: Trophic Level herbivore omnivore low-level predator mid-level predator toppredator 7, 161 species

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 - 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 > 10, 000 100 – 1000 10 – 100 < 10 <1 2– 4 5 – 10 > 10 1– 3 4 – 10 11 – 30 > 30 Fecundity (1/year) tm (years) tmax (years)

Productivity is a Proxy for Metabolism

Trait Correlation: Size vs Troph

Predators are Larger than Prey

Trait Correlation: Size vs Productivity

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

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

Occupation of Size-Troph Space

Occupation of Size-Productivity Space

Occupation of Troph-Productivity Space

Occupation of size–productivity– troph-space for 20, 480 species of fishes. Full cell width is 1000 species. Source: Fish. Base 11/2004

Occupation of size–productivity– troph-space for 620 species of sharks and rays. Full cell width is 1000 species. Source: Fish. Base 11/2004

Life Span and Growth Taylor 1958 Age at 0. 95 L∞ tmax = 3/K

Life Span and Size

The Most Important Point in Life • where growth rate is maximum • where gonad growth rate is maximum • where likely reproductive effort is maximum (ltmt function) • where reproductive biomass of the cohort is maximum topt = 1. 65 E

The Most Important Point in Life topt = 1. 65 E Lopt = 0. 67 L∞ Wopt = 0. 3 W∞

Evolution Does Not Miss… survivallive of bearers offspring Related to parent sharks & rays size low fecundity high of offspring survival 0. 67 L∞ = topt fecundity indepenent of 0. 35 L∞ = topt - E parent size

But Fishing Does… • • Start before first maturity Double mortality (if not more) E = 1/M • • Reduce reproductive phase by half Undermine the productivity on which it depends

Thanks to the Fish. Base Team

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