کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9889590 | 1539024 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ontogeny of salinity tolerance and hyper-osmoregulation by embryos of the intertidal crabs Hemigrapsus edwardsii and Hemigrapsus crenulatus (Decapoda, Grapsidae): Survival of acute hyposaline exposure
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The adults of Hemigrapsus edwardsii and Hemigrapsus crenulatus are euryhaline crabs and strong hyper-osmoregulators. Their embryos are carried externally attached to the abdominal pleopods of female crabs, where they are exposed to temporal and spatial changes in salinity associated with their intertidal and estuarine habitats. Although embryos lack the branchial and excretory organs responsible for adult osmoregulation, post-gastrula embryos were highly tolerant of exposure to hypo-osmotic sea water. Detached eggs (embryos + envelopes), of both species, at all developmental stages between gastrulation and hatching, exhibited 80-100% survival for periods up to 96 h in sea water (osmolality, 1050 mmol kgâ 1) and in dilutions to 50%, 10%, and 1%. Cleavage stages were less tolerant of dilution; H. edwardsii, < 50% survived 24 h in 10% sea water; H. crenulatus < 50% survived 6 h in 10% sea water. Post-gastrulation stages strongly hyper-osmoregulated but cleavage stages were hyper-osmoconformers (maintaining internal osmolality â 150 mmol kgâ 1 above external). Osmoregulatory capacity was reduced just prior hatching, particularly in H. crenulatus, although salinity tolerance remained high. Gastrulation therefore marks a critical stage in the ontogeny of osmoregulation and salinity tolerance. Total Na+/K+-ATPase activity increased greatly during embryogenesis of H. crenulatus (undetectable in blastulae; gastrulae 0.31 ± 0.05 pmol Pi embryoâ 1 minâ 1; pre-hatching 16.4 ± 1.0 pmol Pi embryoâ 1 minâ 1). Na+/K+-ATPase activity increased in embryos exposed to dilute sea water for 24 h implicating regulation of this transporter in a short-term acclimation response.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 140, Issue 4, April 2005, Pages 495-505
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 140, Issue 4, April 2005, Pages 495-505
نویسندگان
H.H. Taylor, Deepani Seneviratna,