Crimesolving technique maps the underground lair of the Slovenian dragon

first_img Click to view the privacy policy. Required fields are indicated by an asterisk (*) Sign up for our daily newsletter Get more great content like this delivered right to you! Country Email FAYETTEVILLE, ARKANSAS—Although the blind cave salamander Proteus anguinus is one of the national animals of Slovenia, it’s so shy that there have been only about 300 sightings in 300 years. Now, molecular biologists have learned how to keep track of these elusive animals without having to see them: by using a new probe that detects their DNA in the springs in which they swim. Already the probe—described here last week at the 2016 International Conference on Subterranean Biology—has detected Proteus in places it’s never been known to go. The approach has also provided tantalizing evidence that a rare black subspecies of the typically white creature might actually be a bona fide species of its own.The work opens up new possibilities for the salamander’s conservation and also for using so-called environmental DNA (eDNA) to monitor animals that live where humans just can’t go. “It has fantastic utility because so many aquatic cave habitats are unavailable to us,” says Rick Olson, an ecologist at Mammoth Cave National Park in Kentucky who was not involved with the work.Cave animals are among the most bizarre and understudied creatures on this planet. And Proteus tops the list, as the world’s biggest cave animal and Europe’s only cave vertebrate. It lives in underground aquifers in Slovenia, surfacing only when floodwaters sweep it from its lair. At 30 centimeters, Proteus is a giant among salamanders, and—like most cave creatures—it has lost its eyes and its color. Lab-raised specimens show that the amphibian can live for more than a century. It becomes sexually mature about the same time as humans (age 14), but it can reproduce only once every 7 years. And it can go years without eating a thing and survive just fine. Four hundred years ago, locals thought the salamanders were baby dragons, with mythical protective powers.center_img Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe But little has been done to ensure the animals’ survival, despite its status as a European “priority” species—one that deserves the government’s protection. The rare, black Proteus may be even more endangered than the white Proteus, the more common form of the species. Since it was first discovered in 1986, it has only been sighted at four springs in southeastern Slovenia.Frustrated that biologists don’t know the first thing about how big or widespread the salamander populations are, Špela Goricki, a molecular biologist at the Tular Cave Laboratory in Kranj, Slovenia, decided to borrow a forensic technique more commonly used in law enforcement: eDNA. The method, which detects DNA from skin cells, hair, and other cells released into the environment, has already been used to track surface organisms like invasive fish and snakes. But it had never before been used to track cave creatures.By analyzing Proteus DNA from previously collected specimens, Goric​ki designed genetic probes, short stretches of genetic material that differentially link to its DNA but bypass that of other organisms. Further, the team has designed the probes so they can differentiate white Proteus DNA from black. Goric​ki and her colleagues then systematically surveyed dozens of springs and caves in Slovenia known or suspected to have Proteus residents. They also checked underground water in nearby Montenegro and Herzegovina.Black Proteus DNA showed up in five new places all within a few kilometers of each other. The team also found evidence for white Proteus in new spots, including Herzegovina and Montenegro. What’s more, the team found the first evidence that these two groups might sometimes live side by side, suggesting that they are two separate species. If they were a single species, such side-by-side living would lead to interbreeding. But that doesn’t seem to have happened, Goric​ki says.But the wider range doesn’t mean that the salamanders are any safer than they were. More agriculture in the area means more nitrogen and phosphorous in the aquifers where they live, which could be toxic to the animals, Goric​ki says. “I hope the conservation authorities will fulfill their promise” to develop more effective ways to protect this species, she adds.Even if that plan is slow in coming, Goric​ki thinks her success will pave the way for other eDNA monitoring programs. “In 10 years, this will be the method of choice for rare and endangered species, as well as invasive species,” she predicts. Olson agrees. At Mammoth Cave National Park, researchers have already begun to use eDNA to keep track of the endangered Kentucky cave shrimp, Palaemonias ganteri. “Environmental DNA gives us a way of not only knowing if it’s present, but also the concentration of DNA can give an idea of relative abundance,” Olson says. And that will go a long way in helping conserve these species.last_img read more