Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?

Benni Winding Hansen, Guillaume Drillet, Morten Foldager Pedersen, Kristian P. Sjøgren, Bent Vismann

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3 at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity. In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect osmometer in the salinity range of 5–35 psu. We hypothesize further that the embryo is able to keep its volume and osmolality constant due to the impermeability of the inner plasma membrane of the egg or by a combination of osmoregulation and reduced permeability of the inner plasma membrane.
OriginalsprogEngelsk
TidsskriftJournal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
Vol/bind182
Udgave nummer5
Sider (fra-til)613-623
Antal sider11
ISSN0174-1578
DOI
StatusUdgivet - jul. 2012

Citer dette

@article{1680a852b66a439dac2023105aef5499,
title = "Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?",
abstract = "Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3 at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity. In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect osmometer in the salinity range of 5–35 psu. We hypothesize further that the embryo is able to keep its volume and osmolality constant due to the impermeability of the inner plasma membrane of the egg or by a combination of osmoregulation and reduced permeability of the inner plasma membrane.",
author = "Hansen, {Benni Winding} and Guillaume Drillet and Pedersen, {Morten Foldager} and Sj{\o}gren, {Kristian P.} and Bent Vismann",
year = "2012",
month = "7",
doi = "10.1007/s00360-012-0646-y",
language = "English",
volume = "182",
pages = "613--623",
journal = "Journal of Comparative Physiology B: Biochemical, Systems, and Environmental Physiology",
issn = "0174-1578",
publisher = "Physica-Verlag",
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Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes? / Hansen, Benni Winding; Drillet, Guillaume; Pedersen, Morten Foldager; Sjøgren, Kristian P.; Vismann, Bent.

I: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, Bind 182, Nr. 5, 07.2012, s. 613-623.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?

AU - Hansen, Benni Winding

AU - Drillet, Guillaume

AU - Pedersen, Morten Foldager

AU - Sjøgren, Kristian P.

AU - Vismann, Bent

PY - 2012/7

Y1 - 2012/7

N2 - Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3 at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity. In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect osmometer in the salinity range of 5–35 psu. We hypothesize further that the embryo is able to keep its volume and osmolality constant due to the impermeability of the inner plasma membrane of the egg or by a combination of osmoregulation and reduced permeability of the inner plasma membrane.

AB - Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3 at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity. In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect osmometer in the salinity range of 5–35 psu. We hypothesize further that the embryo is able to keep its volume and osmolality constant due to the impermeability of the inner plasma membrane of the egg or by a combination of osmoregulation and reduced permeability of the inner plasma membrane.

U2 - 10.1007/s00360-012-0646-y

DO - 10.1007/s00360-012-0646-y

M3 - Journal article

VL - 182

SP - 613

EP - 623

JO - Journal of Comparative Physiology B: Biochemical, Systems, and Environmental Physiology

JF - Journal of Comparative Physiology B: Biochemical, Systems, and Environmental Physiology

SN - 0174-1578

IS - 5

ER -