title: Physiological responses and scope for growth upon medium-term exposure to the combined effects of ocean acidification and temperature in a subtidal scavenger Nassarius conoidalis.
abstract: Physiological responses (ingestion rate, absorption rate and efficiency, respiration, rate, excretion rate) and scope for growth of a subtidal scavenging gastropod Nassarius conoidalis under the combined effects of ocean acidification (pCO2 levels: 380, 950, 1250 μatm) and temperature (15, 30 °C) were investigated for 31 days. There was a significant reduction in all the physiological rates and scope for growth following short-term exposure (1-3 days) to elevated pCO2 except absorption efficiency at 15 °C and 30 °C, and respiration rate and excretion rate at 15 °C. The percentage change in the physiological rates ranged from 0% to 90% at 15 °C and from 0% to 73% at 30 °C when pCO2 was increased from 380 μatm to 1250 μatm. The effect of pCO2 on the physiological rates was enhanced at high temperature for ingestion, absorption, respiration and excretion. When the exposure period was extended to 31 days, the effect of pCO2 was significant on the ingestion rate only. All the physiological rates remained unchanged when temperature increased from 24 °C to 30 °C but the rates at 15 °C were significantly lower, irrespective of the duration of exposure. Our data suggested that a medium-term exposure to ocean acidification has no effect on the energetics of N. conoidalis. Nevertheless, the situation may be complicated by a longer term of exposure and/or a reduction in salinity in a warming world.
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China.
authors.forename: Haoyu
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China.
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Shin
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, Hong Kong, China; State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China. Electronic address: bhsgche@cityu.edu.hk.
authors.forename: S G
authors.initials: SG
authors.lastname: Cheung
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004734:Energy Metabolism; D004781:Environmental Exposure; D049851:Gastropoda / Q000254:growth & development / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*; D013696:Temperature
keywords: Gastropods; Nassarius conoidalis; Ocean acidification; Physiological energetics; Temperature