日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

   

Tropical fish can live for months out of water

(Agencies)
Updated: 2007-11-15 07:23

GUATEMALA CITY -- A tropical fish that lives in mangrove swamps across the Americas can survive out of water for months at a time, similar to how animals adapted to land millions of years ago, a new study shows.


A tropical fish meanders through the sea waters of Kurumba island in the Maldives, 12 November, 2007. [Agencies]

The Mangrove Rivulus, a type of small tropical killifish, seeks refuge in shallow pools of water in crab burrows, coconut shells or even old beer cans in the tropical mangrove swamps of Belize, the United States and Brazil.

When their habitat dries up, they live on the land in logs, said Scott Taylor, a researcher at the Brevard County Environmentally Endangered Lands Program in central Florida.

The fish, whose scientific name is Rivulus marmoratus, can grow as large as three inches. They group together in logs hollowed out by insects and breathe air through their skin instead of their gills until they can find water again.

The scientific breakthrough came after a trip to Belize.

"We kicked over a log and the fish just came tumbling out," Taylor told Reuters in neighboring Guatemala by telephone. He said he will publish his study on the fish in The American Naturalist journal early next year.

In lab tests, Taylor said he found the fish can survive for up to 66 days out of water without eating, and their metabolism keeps functioning.

Clue to Evolution

Some other fish can survive briefly out of water. The walking catfish found in Southeast Asia can wriggle over land for hours at a time, while lungfish found in Australia, Africa and South America can survive out of water, but only in a dormant state.

No other known fish can be out of water as long as the Mangrove Rivulus and remain active, according to Patricia Wright, a biologist at Canada's University of Guelph.

"They can survive for weeks without really dropping their metabolic rate. They remain relatively responsive and active for weeks in air," she said.

The fish may hold clues to how animals evolved over time.

"These animals live in an environment that is similar to conditions that existed millions of year ago, when animals began making the transition from water onto land," she added.

Surviving on land is not the only unusual behavior exhibited by the fish. They have both testes and ovaries and essentially clone themselves by laying their own, already fertilized eggs.

"This is probably the coolest fish around, not only do they have a very bizarre sex life, but they really don't meet standard behavioral criteria for fishes," said Taylor in a summary of his paper.



Top World News  
Today's Top News  
Most Commented/Read Stories in 48 Hours
主站蜘蛛池模板: 国外黄色片 | 天天操综合 | 日韩色av| xxxxx在线| 亚洲第一区在线 | 狠狠操网 | 日韩精品极品视频在线观看免费 | xxxx77hd国产| 日本片网址 | 激情综合激情五月 | 日韩免费视频网站 | 大伊人久久| 国产国语性生话播放 | 国产精品情侣呻吟对白视频 | 成人夜间视频 | 亚洲婷婷网 | 4444在线观看| 日产av在线| 亚洲爱爱网 | 最新国产在线视频 | 亚洲区小说区图片区qvod | 可以在线看的av | 亚洲精品女人 | 免费av在线播放 | 大黄网站在线观看 | 天天干天天干天天操 | 亚洲精品无吗 | 麻豆久久久久久久 | 在线看成人片 | 日本高清视频一区二区 | 国产精品免费在线视频 | 亚洲天堂中文字幕在线观看 | 激情网五月 | 91精品国产91久久久久青草 | 成人在线三级 | 欧美野战| 三级福利视频 | 国产综合第一页 | 精品免费久久久 | 亚洲欧美国产高清va在线播放 | 天天色天天 |