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| The Causative Survey of Sudden Death of Manila Clam Ruditapes philippinarum Cultured in Hangu,Tianjin |
| LI Yong-ren,GUO Yong-jun,XING Ke-zhi |
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Abstract Manila clam Ruditapes philip pinarum ,sowing in Hangu shallow sea ,occurred serious death with the mortality as high as 86 .2% ,and the grow th was slow from September to October in 2012 .The survey showed that (1)mortality of clams increased with increase in stocking density ;(2)heavy metals , petroleum hydrocarbons and other chemical factors in the seawater and sediments were not excessive ;(3) chlorophyll concentration and primary production were significantly lower from June to August .A large number of mussels Musculus senhousei occurred in mid-June ,and disappeared from September to October , when clams death seriously .The cause of this death in clams was speculated that :the M .senhousei existed in surface sediments competed for food and dissolved oxygen with clams ;mass byssus network impacted clams for feeding and breathing .In addition ,the lower primary production exacerbated the death of the clams .
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Received: 25 July 2013
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