University of Tasmania

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Latitudinal diversity gradients for five taxonomic levels of marine fish in depth zones

journal contribution
posted on 2023-05-20, 19:34 authored by Lin, H-Y, Stephen CorkreyStephen Corkrey, Kaschner, K, Garilao, C, Costello, MJ
Latitudinal diversity gradients (LDGs) of species richness in most marine taxa appear to be bimodal with a dip at the equator. We compared LDGs for modeled ranges of 5,619 marine fish species, and distinguished between: all, pelagic, demersal, bony and cartilaginous fish groups; five taxonomic levels of class, order, family, genus and species; and four depth zones namely whole water column, 0–200 m, 200–1,000 m, and 1,000–6,000 m; at 5° latitudinal intervals. The modality of 88 LDGs was examined visually and using Hartigan's dip statistic. We found 80 LDGs were bimodal (or not unimodal), two gradients were unimodal and six gradients were ambiguous. All species and genera, and 19 families among fish groups and depth zones had bimodal or not unimodal LDGs. The northern hemisphere mode had 2–6% greater richness from species to order richness. Overall fish, the peak of richness shifted poleward across taxonomic levels, from 25°N for species to median 48°N for class and from 10°S for genus to 35°S for class. Temperature and salinity were significantly correlated with the LDG. Our findings using fish species ranges support previous analyses using species' occurrences, namely that the LDG of marine species is bimodal, by generalizing this to all taxonomic levels and depth zones. That the LDG with a dip near the equator supports the hypothesis that it is primarily temperature driven, and that the equator is already too hot for some species.


Publication title

Ecological Research






Tasmanian Institute of Agriculture (TIA)


Blackwell Publishing Asia

Place of publication

54 University St, P O Box 378, Carlton, Australia, Victoria, 3053

Rights statement

Copyright 2020 The Ecological Society of Japan

Repository Status

  • Restricted

Socio-economic Objectives

Marine biodiversity

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