Metabolic Recovery and Compensatory Shell Growth of Juvenile Pacific Geoduck Panopea Generosa Following Short-Term Exposure to Acidified Seawater

AbstractWhile acute stressors can be detrimental, environmental stress conditioning can improve performance. To test the hypothesis that physiological status is altered by stress conditioning, we subjected juvenile Pacific geoduck, Panopea generosa, to repeated exposures of elevated pCO2 in a commercial hatchery setting followed by a period in ambient common garden. Respiration rate and shell length were measured for juvenile geoduck periodically throughout short-term repeated reciprocal exposure periods in ambient (~550 µatm) or elevated (~2400 µatm) pCO2 treatments and in common, ambient conditions, five months after exposure. Short-term exposure periods comprised an initial 10-day exposure followed by 14 days in ambient before a secondary 6-day reciprocal exposure. The initial exposure to elevated pCO2 significantly reduced respiration rate by 25% relative to ambient conditions, but no effect on shell growth was detected. Following 14 days in common garden, ambient conditions, reciprocal exposure to elevated or ambient pCO2 did not alter juvenile respiration rates, indicating ability for metabolic recovery under subsequent conditions. Shell growth was negatively affected during the reciprocal treatment in both exposure histories, however clams exposed to the initial elevated pCO2 showed compensatory growth with 5.8% greater shell length (on average between the two secondary exposures) after five months in ambient conditions. Additionally, clams exposed to the secondary elevated pCO2 showed 52.4% increase in respiration rate after five months in ambient conditions. Early exposure to low pH appears to trigger carry-over effects suggesting bioenergetic re-allocation facilitates growth compensation. Life stage-specific exposures to stress can determine when it may be especially detrimental, or advantageous, to apply stress conditioning for commercial production of this long-lived burrowing clam.Lay summaryCommercial shellfish hatcheries provide essential food security, but often production can be hampered by sensitivity of shellfish at early life stages. Repeated short-term exposures can increase tolerance and performance of the geoduck clam with implications for sustainable aquaculture.

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Metabolic recovery and compensatory shell growth of juvenile Pacific geoduck Panopea generosa following short-term exposure to acidified seawater

Conservation Physiology ◽

10.1093/conphys/coaa024 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Samuel J Gurr ◽

Brent Vadopalas ◽

Steven B Roberts ◽

Hollie M Putnam

Keyword(s):

Respiration Rate ◽

Shell Length ◽

Shell Growth ◽

Common Garden ◽

Elevated Pco2 ◽

Ambient Conditions ◽

Short Term ◽

Metabolic Recovery ◽

Short Term Exposure ◽

Stress Conditioning

Abstract While acute stressors can be detrimental, environmental stress conditioning can improve performance. To test the hypothesis that physiological status is altered by stress conditioning, we subjected juvenile Pacific geoduck, Panopea generosa, to repeated exposures of elevated pCO2 in a commercial hatchery setting followed by a period in ambient common garden. Respiration rate and shell length were measured for juvenile geoduck periodically throughout short-term repeated reciprocal exposure periods in ambient (~550 μatm) or elevated (~2400 μatm) pCO2 treatments and in common, ambient conditions, 5 months after exposure. Short-term exposure periods comprised an initial 10-day exposure followed by 14 days in ambient before a secondary 6-day reciprocal exposure. The initial exposure to elevated pCO2 significantly reduced respiration rate by 25% relative to ambient conditions, but no effect on shell growth was detected. Following 14 days in common garden, ambient conditions, reciprocal exposure to elevated or ambient pCO2 did not alter juvenile respiration rates, indicating ability for metabolic recovery under subsequent conditions. Shell growth was negatively affected during the reciprocal treatment in both exposure histories; however, clams exposed to the initial elevated pCO2 showed compensatory growth with 5.8% greater shell length (on average between the two secondary exposures) after 5 months in ambient conditions. Additionally, clams exposed to the secondary elevated pCO2 showed 52.4% increase in respiration rate after 5 months in ambient conditions. Early exposure to low pH appears to trigger carryover effects suggesting bioenergetic re-allocation facilitates growth compensation. Life stage-specific exposures to stress can determine when it may be especially detrimental, or advantageous, to apply stress conditioning for commercial production of this long-lived burrowing clam.

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The importance of monitoring metabolic recovery in the coral Acropora cervicornis after short-term exposure to drilling muds: Calcification rate and protein concentration

Coral Reefs ◽

10.1007/bf00263575 ◽

1984 ◽

Vol 2 (4) ◽

pp. 215-225 ◽

Cited By ~ 4

Author(s):

J. J. Kendall ◽

E. N. Powell ◽

S. J. Connor ◽

T. J. Bright ◽

C. E. Zastrow

Keyword(s):

Protein Concentration ◽

Acropora Cervicornis ◽

Short Term ◽

Calcification Rate ◽

Metabolic Recovery ◽

Short Term Exposure ◽

Drilling Muds

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The impacts of past, present and future ocean chemistry on predatory planktonic snails

Royal Society Open Science ◽

10.1098/rsos.202265 ◽

2021 ◽

Vol 8 (8) ◽

pp. 202265

Author(s):

Deborah Wall-Palmer ◽

Lisette Mekkes ◽

Paula Ramos-Silva ◽

Linda K. Dämmer ◽

Erica Goetze ◽

...

Keyword(s):

Gene Expression ◽

Shell Thickness ◽

Shell Growth ◽

Ambient Conditions ◽

Carbonate Chemistry ◽

Short Term ◽

Ocean Chemistry ◽

Decreasing Ph ◽

Organismal Development ◽

Shell Production

The atlantid heteropods represent the only predatory, aragonite shelled zooplankton. Atlantid shell production is likely to be sensitive to ocean acidification (OA), and yet we know little about their mechanisms of calcification, or their response to changing ocean chemistry. Here, we present the first study into calcification and gene expression effects of short-term OA exposure on juvenile atlantids across three pH scenarios: mid-1960s, ambient and 2050 conditions. Calcification and gene expression indicate a distinct response to each treatment. Shell extension and shell volume were reduced from the mid-1960s to ambient conditions, suggesting that calcification is already limited in today's South Atlantic. However, shell extension increased from ambient to 2050 conditions. Genes involved in protein synthesis were consistently upregulated, whereas genes involved in organismal development were downregulated with decreasing pH. Biomineralization genes were upregulated in the mid-1960s and 2050 conditions, suggesting that any deviation from ambient carbonate chemistry causes stress, resulting in rapid shell growth. We conclude that atlantid calcification is likely to be negatively affected by future OA. However, we also found that plentiful food increased shell extension and shell thickness, and so synergistic factors are likely to impact the resilience of atlantids in an acidifying ocean.

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The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648027 ◽

1976 ◽

Vol 36 (01) ◽

pp. 221-229 ◽

Cited By ~ 16

Author(s):

Charles A. Schiffer ◽

Caroline L. Whitaker ◽

Morton Schmukler ◽

Joseph Aisner ◽

Steven L. Hilbert

Keyword(s):

Platelet Count ◽

Platelet Aggregation ◽

Dimethyl Sulfoxide ◽

Platelet Function ◽

Platelet Volume ◽

Short Term ◽

Platelet Factor ◽

Short Term Exposure ◽

Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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Validation of On-line Respiration Meter and its Applications by Computer Simulation

Water Science & Technology ◽

10.2166/wst.1992.0578 ◽

1992 ◽

Vol 26 (5-6) ◽

pp. 1355-1363 ◽

Cited By ~ 2

Author(s):

C-W. Kim ◽

H. Spanjers ◽

A. Klapwijk

Keyword(s):

Steady State ◽

Activated Sludge ◽

Respiration Rate ◽

Oxygen Demand ◽

Operating Conditions ◽

Mass Balances ◽

Short Term ◽

Respiration Rates ◽

On Line ◽

Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

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