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

Citation

Higgins, FA and Bates, AE and Lamare, MD, Heat tolerance, behavioural temperature selection and temperature-dependent respiration in larval Octopus huttoni, Journal of Thermal Biology, 37 pp. 83-88. ISSN 0306-4565 (2012) [Refereed Article]


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DOI: doi:10.1016/j.jtherbio.2011.11.004

Abstract

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 165.2 nmol larvae−1 h−1 in one-day old larvae to 40.1–99.4 nmol 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.

Item Details

Item Type:Refereed Article
Keywords:lethal thermal limit, critical thermal maximum, selected temperature, Octopus huttoni, Robsonbella huttoni, paralarvae
Research Division:Environmental Sciences
Research Group:Ecological Applications
Research Field:Ecological Impacts of Climate Change
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Marine Flora, Fauna and Biodiversity
Author:Bates, AE (Dr Amanda Bates)
ID Code:76413
Year Published:2012
Web of Science® Times Cited:11
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2012-03-06
Last Modified:2014-03-26
Downloads:1 View Download Statistics

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