Deakin University
Browse

File(s) under permanent embargo

Heat tolerance, behavioural temperature selection and temperature-dependent respiration in larval Octopus huttoni

journal contribution
posted on 2012-01-01, 00:00 authored by F Higgins, Amanda Bates, M Lamare
This study reports temperature effects on paralarvae from a benthic octopus species, Octopus huttoni, found throughout New Zealand and temperate Australia. We quantified the thermal tolerance, thermal preference and temperature-dependent respiration rates in 1-5 days old paralarvae. Thermal stress (1°C increase h-1) and thermal selection (~10-24°C vertical gradient) experiments were conducted with paralarvae reared for 4 days at 16°C. In addition, measurement of oxygen consumption at 10, 15, 20 and 25°C was made for paralarvae aged 1, 4 and 5 days using microrespirometry. Onset of spasms, rigour (CTmax) and mortality (upper lethal limit) occurred for 50% of experimental animals at, respectively, 26.0±0.2°C, 27.8±0.2°C and 31.4±0.1°C. The upper, 23.1±0.2°C, and lower, 15.0±1.7°C, temperatures actively avoided by paralarvae correspond with the temperature range over which normal behaviours were observed in the thermal stress experiments. Over the temperature range of 10°C-25°C, respiration rates, standardized for an individual larva, increased with age, from 54.0 to 165.2nmol larvae-1h-1 in one-day old larvae to 40.1-99.4nmol h-1 at five days. Older larvae showed a lesser response to increased temperature: the effect of increasing temperature from 20 to 25°C (Q10) on 5 days old larvae (Q10=1.35) was lower when compared with the 1 day old larvae (Q10=1.68). The lower Q10 in older larvae may reflect age-related changes in metabolic processes or a greater scope of older larvae to respond to thermal stress such as by reducing activity. Collectively, our data indicate that temperatures >25°C may be a critical temperature. Further studies on the population-level variation in thermal tolerance in this species are warranted to predict how continued increases in ocean temperature will limit O. huttoni at early larval stages across the range of this species.

History

Journal

Journal of thermal biology

Volume

37

Issue

1

Pagination

83 - 88

Publisher

Elsevier

Location

Amsterdam, The Netherlands

ISSN

0306-4565

eISSN

1879-0992

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2011, Elsevier

Usage metrics

    Research Publications

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC