The cause of death of Caribbean sea urchins加勒比海胆的死因

关军红

海膽是一种表面长着许多长刺的动物。去年，加勒比的海胆开始生病，是什么导致的呢？

Scientists say a small parasite （寄生虫） is the cause of death of many seaurchins in the Caribbean Sea. Sea urchinsare simple animals that have long spines（脊柱）.

Last year， the long?spined sea ur?chins， also known as Diadema antillarum，started getting sick. They were losing theirspines and their sticky feet were losingtheir grip on the coral reefs. The loss of somany sea urchins， which eat algae （海藻）that grow on the coral， affected the under?sea environment from the Virgin Islands toPuerto Rico to Florida.

Mya Breitbart led a team of scientistswho investigated the sickness. She is amarine microbiologist at the University ofSouth Florida. The team presented theirstudy recently in the scientific publicationScience Advances. “The case is closed，”Breitbart said.

The scientists compared the sick urchins to healthy ones and determined a single?celled parasite was to blame. IanHewson is a marine disease researcher atCornell University in the state of NewYork. He said the team ruled out bacteriaor viruses.

But the team did see single?celledorganisms called ciliates in the sick ur?chins. The scientists then put a group ofhealthy sea urchins grown in a laboratoryin a tank with some of the parasites. Six ofthe 10 urchins in the tank later died. Thescientists are now working to find a way toprevent future losses. They do not have atreatment for the sea urchins， but they arehoping to learn how the parasites spread sothey can stop them.

Reading Check

What causes the death of many seaurchins in the Caribbean Sea according tothe text？

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