Scientists Learn What Killed Caribbean Sea Urchins

Scientists say a small parasite¹ is the cause of death of many sea urchins³ in the Caribbean Sea.

Sea urchins are simple animals that have long spines⁵.

Last year, the long-spined sea urchins, also known as Diadema antillarum, started getting sick. They were losing their spines and their sticky feet were losing their grip on the coral reefs.

The loss of so many sea urchins, which eat algae⁶ that grow on the corals, affected⁷ the undersea environment from the Virgin⁸ Islands to Puerto Rico to Florida.

Mya Breitbart led a team of scientists who investigated the sickness. She is a marine⁹ microbiologist at the University of South Florida.

The team presented their study recently in the scientific publication Science Advances.

"The case is closed," Breitbart said.

The scientists compared the sick urchins to healthy ones and determined¹⁰ a single-celled parasite was to blame.

Ian Hewson is a marine disease researcher at Cornell University in the state of New York. He said the team ruled out bacteria or viruses. But the team did see single-celled organisms called ciliates in the sick urchins.

The scientists then put a group of healthy sea urchins grown in a laboratory in a tank with some of the parasites¹¹. Six of the 10 urchins in the tank later died.

The scientists are now working to find a way to prevent future losses. They do not have a treatment for the sea urchins, but they are hoping to learn how the parasites spread so they can stop them.

Breitbart noted¹² another time that many sea urchins died in the 1980s. She did not know if the same parasites caused that problem.

Don Levitan is a marine scientist at Florida State University who was not involved in the study. He said the two urchin² die-offs, or widespread losses of the animals, have changed the coral reefs in the Caribbean Sea. He said at one time, they were covered with spiny¹³ urchins, but now they are covered in algae, sick from disease and stressed by rising water temperatures.

"Coral reefs in the Caribbean are in trouble," he said. "We are at a different place than we were 30, 40 years ago."

Words in This Story

parasite –n. a plant or animal that lives by taking food or shelter from another living thing

spine⁴ –n. a sharp, pointy part of an animal or plant

sticky –adj. a quality of being easily stuck to

marine –adj. related to the sea

stressed –adj. feeling worried or tired; showing the effects of disease or difficulty

1 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

2 urchin   

n.顽童；海胆

参考例句：

• You should sheer off the urchin.你应该躲避这顽童。
• He is a most wicked urchin.他是个非常调皮的顽童。

3 urchins   

n.顽童( urchin的名词复数 )；淘气鬼；猬；海胆

参考例句：

• Some dozen barefooted urchins ganged in from the riverside. 几十个赤足的顽童从河边成群结队而来。 来自《简明英汉词典》
• People said that he had jaundice and urchins nicknamed him "Yellow Fellow." 别人说他是黄胆病，孩子们也就叫他“黄胖”了。 来自汉英文学 - 中国现代小说

4 spine   

n.脊柱，脊椎；(动植物的)刺；书脊

参考例句：

• He broke his spine in a fall from a horse.他从马上跌下摔断了脊梁骨。
• His spine developed a slight curve.他的脊柱有点弯曲。

5 spines   

n.脊柱( spine的名词复数 )；脊椎；（动植物的）刺；书脊

参考例句：

• Porcupines use their spines to protect themselves. 豪猪用身上的刺毛来自卫。
• The cactus has spines. 仙人掌有刺。 来自《现代英汉综合大词典》

6 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

7 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

8 virgin   

n.处女，未婚女子；adj.未经使用的；未经开发的

参考例句：

• Have you ever been to a virgin forest?你去过原始森林吗？
• There are vast expanses of virgin land in the remote regions.在边远地区有大片大片未开垦的土地。

9 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

10 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

11 parasites   

寄生物( parasite的名词复数 )； 靠他人为生的人； 诸虫

参考例句：

• These symptoms may be referable to virus infection rather than parasites. 这些症状也许是由病毒感染引起的，而与寄生虫无关。
• Kangaroos harbor a vast range of parasites. 袋鼠身上有各种各样的寄生虫。

12 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

13 spiny   

adj.多刺的，刺状的；n.多刺的东西

参考例句：

• This is the Asiatic ornamental shrub with spiny branches and pink blossoms.这就是亚洲的一种观赏灌木，具有多刺的枝和粉红色的花。
• Stay away from a spiny cactus.远离多刺仙人掌。