کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10818876 1060271 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Some euryhalinity may be more common than expected in marine elasmobranchs: The example of the South American skate Zapteryx brevirostris (Elasmobranchii, Rajiformes, Rhinobatidae)
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Some euryhalinity may be more common than expected in marine elasmobranchs: The example of the South American skate Zapteryx brevirostris (Elasmobranchii, Rajiformes, Rhinobatidae)
چکیده انگلیسی
Elasmobranchs are essentially marine, but ~ 15% of the species occur in brackish or freshwater. The Brazilian marine coastal skate Zapteryx brevirostris, non-reported in nearby estuaries, was submitted to 35, 25, 15, and 5 psu, for 6 or 12 h (n = 6). Plasma was assayed for osmolality, urea, and ions (Na+, Cl−, K+, Mg2 +). Muscle water content was determined, and the rectal gland, kidney and gills were removed for carbonic anhydrase (CA) and Na+,K+-ATPase (NKA) activities. The skate survived to all treatments. Plasma osmolality and urea levels decreased respectively by 27% and 38% after 12 h in 5 psu (with respect to levels when in seawater), but plasma Na+, Cl−, and Mg2 + were well regulated. Plasma K+ showed some conformation after 12 h. Muscle hydration was maintained. Branchial CA and NKA did not respond to salinity. Rectal gland NKA decreased upon seawater dilution, while renal NKA increased. This skate was shown to be partially euryhaline. The analysis of plasma urea of elasmobranchs in brackish and freshwater versus salinity and time-allied to the widespread occurrence of some euryhalinity in the group-led us to revisit the hypothesis of a brackish water habitat for elasmobranch ancestors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 166, Issue 1, September 2013, Pages 36-43
نویسندگان
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