کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9465843 | 1622778 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Intermittent exposure to reduced oxygen levels affects prey size selection and consumption in swimming crab Thalamita danae Stimpson
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
اقیانوس شناسی
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چکیده انگلیسی
Portunid crabs Thalamita danae (carapace width: 46-56 mm) were exposed to low oxygen level (4.0 mg O2 lâ1) and hypoxia (1.5 mg O2 lâ1) for 6 h each day with three size classes (large: 15.0-19.9 mm, medium: 10.0-14.9 mm, small: 5.0-9.9 mm) of mussels Brachidontes variabilis offered as food. Consumption rate, prey size preference, and prey handling including breaking time, handling time, eating time and prey value, were studied during the time the crabs were exposed to reduced oxygen levels and results were compared with the crabs maintained at high oxygen level (8.0 mg O2 lâ1) throughout the experiment. Consumption of mussels from all size classes was significantly higher at high oxygen level than at reduced oxygen levels. No mussel size preference was observed for crabs exposed to 4.0 or 8.0 mg O2 lâ1 but those crabs exposed to 1.5 mg O2 lâ1 preferred medium mussels. Both breaking time and handling time increased with mussel size but did not vary with oxygen level. Prey value of each mussel consumed (mg dry wt eaten crabâ1 sâ1) was calculated by dividing the estimated dry weight of the mussel by the observed handling time. Mean prey value varied significantly with mussel size, with values obtained for large mussels being higher than small mussels at 4.0 and 8.0 mg O2 lâ1; the effect of oxygen level, however, was insignificant. In view of portunid crabs as major predators of mussels, results may help explain dominance of mussels in eutrophic harbours in Hong Kong.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Marine Pollution Bulletin - Volume 51, Issues 8â12, 2005, Pages 1003-1009
Journal: Marine Pollution Bulletin - Volume 51, Issues 8â12, 2005, Pages 1003-1009
نویسندگان
P.K.S. Shin, P.H. Cheung, F.Y. Yang, S.G. Cheung,