Original Paper

Evolutionary Ecology

, Volume 24, Issue 4, pp 749-759

An acquisition trade-off with fast growth in a fish, the medaka Oryzias latipes: why do low-latitude ectotherms grow more slowly?

  • Yuya SuzukiAffiliated withGraduate School of Science and Technology, Niigata University Email author 
  • , Takashi MiyakeAffiliated withGraduate School of Science and Technology, Niigata University
  • , Kazunori YamahiraAffiliated withGraduate School of Science and Technology, Niigata University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

In various ectotherms, it is well-known that high-latitude individuals grow faster at any temperature than do low-latitude individuals as an adaptation to shorter growing seasons. The submaximal growth of low-latitude ectotherms implies that there exist trade-offs with fast growth. Although there is accumulating evidence for latitudinal variation in growth capacity, however, few studies have demonstrated these trade-offs. In this study, using a freshwater fish Oryzias latipes as a model organism, we tested whether there is an acquisition trade-off in which the higher growth capacity of high-latitude individuals is realized by foraging more intensively, despite the risk of predation. Foraging experiments revealed that higher-latitude O. latipes juveniles captured more prey per unit time than lower-latitude juveniles at any temperature. In addition, predation experiments revealed that higher-latitude juveniles were more frequently killed by dragonfly larvae. Observations of swimming behaviors demonstrated that the higher vulnerability to predation in high-latitude O. latipes is probably caused by lower steady- and burst-swimming performances due to the larger meal size, and partially by reduced caution due to a greater willingness to forage. We conclude that acquisition trade-offs may be the primary constraint on growth evolution across latitudes among fishes. This implies that growth capacity evolves in response not only to the length of the growing season but also to predation pressures.

Keywords

Growth Latitude Oryzias latipes Predation Resource acquisition Trade-off