biotoxin       
noun [ C ] uk/ˈbaɪ.əʊˌtɒk.sɪn/ us/ˌbaɪ.oʊˈtɑːk.sɪn/
 生物毒素
a poisonous substance that is produced inside a living thing
  The batch of mussels was tested and found to have high levels of the marine biotoxin known to cause paralytic shellfish poisoning.  经检测,这批贻贝含有高浓度的海洋生物毒素,这种毒素会导致麻痺性贝类中毒。 
 - More examples
 - She and other scientists determined that domoic acid, a biotoxin that can cause disease and death in humans, caused the sea lions' illnesses and deaths.
 - In the 1970s they developed a biotoxin derived from the castor-bean plant.
 - The edema in the dead birds' lungs might be indicative of exposure to a marine biotoxin.
 - The spike had been filled with ricin – a deadly biotoxin – and punched into his thigh as he walked down the street.