We in Telegram
Add news
March 2010 April 2010 May 2010 June 2010 July 2010
August 2010
September 2010 October 2010
November 2010
December 2010
January 2011
February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 July 2012 August 2012 September 2012 October 2012 November 2012 December 2012 January 2013 February 2013 March 2013 April 2013 May 2013 June 2013 July 2013 August 2013 September 2013 October 2013 November 2013 December 2013 January 2014 February 2014 March 2014 April 2014 May 2014 June 2014 July 2014 August 2014 September 2014 October 2014 November 2014 December 2014 January 2015 February 2015 March 2015 April 2015 May 2015 June 2015 July 2015 August 2015 September 2015 October 2015 November 2015 December 2015 January 2016 February 2016 March 2016 April 2016 May 2016 June 2016 July 2016 August 2016 September 2016 October 2016 November 2016 December 2016 January 2017 February 2017 March 2017 April 2017 May 2017 June 2017 July 2017 August 2017 September 2017 October 2017 November 2017 December 2017 January 2018 February 2018 March 2018 April 2018 May 2018 June 2018 July 2018 August 2018 September 2018 October 2018 November 2018 December 2018 January 2019 February 2019 March 2019 April 2019 May 2019 June 2019 July 2019 August 2019 September 2019 October 2019 November 2019 December 2019 January 2020 February 2020 March 2020 April 2020 May 2020 June 2020 July 2020 August 2020 September 2020 October 2020 November 2020 December 2020 January 2021 February 2021 March 2021 April 2021 May 2021 June 2021 July 2021 August 2021 September 2021 October 2021 November 2021 December 2021 January 2022 February 2022 March 2022 April 2022 May 2022 June 2022 July 2022 August 2022 September 2022 October 2022 November 2022 December 2022 January 2023 February 2023 March 2023 April 2023 May 2023 June 2023 July 2023 August 2023 September 2023 October 2023 November 2023 December 2023 January 2024 February 2024 March 2024 April 2024 May 2024
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
22
23
24
25
26
27
28
29
30
31
News Every Day |

Oh Great, Spiders Can Swim

This article was originally published in Knowable Magazine.

Shrubbery, toolsheds, basements—these are places one might expect to find spiders. But what about the beach? Or in a stream? Some spiders make their homes near or, more rarely, in water: tucking into the base of kelp stalks, spinning watertight cocoons in ponds or lakes, hiding under pebbles at the seaside or along a creek bank.

“Spiders are surprisingly adaptable, which is one of the reasons they can inhabit this environment,” says Ximena Nelson, a behavioral biologist at the University of Canterbury in Christchurch, New Zealand.

Finding aquatic or semiaquatic spiders is difficult work, Nelson says: She and a student have spent four years chasing a jumping spider known as Marpissa marina around the pebbly seaside beaches it likes, but too often, as soon as they manage to find one, it disappears under rocks. And sadly, some aquatic spiders may disappear altogether before they come to scientists’ attention, as their watery habitats shrivel because of climate change and other human activities.

What scientists do know is that dozens of described spider species spend at least some of their time in or near the water, and more are almost surely awaiting discovery, says Sarah Crews, an arachnologist at the California Academy of Sciences, in San Francisco. It also appears that spiders evolved aquatic preferences on several distinct occasions throughout the history of this arthropod order. Crews and colleagues surveyed spiders and reported in 2019 that 21 taxonomic families are associated with aquatic habitats, suggesting that the evolutionary event occurred multiple independent times. Only a swashbuckling few—not even 0.3 percent of described spider species—are seashore spiders; many more have been found near fresh water, Nelson says.

It’s not clear what would induce successful land-dwelling critters to move to watery habitats. Spiders, as a group, probably evolved about 400 million years ago from chunkier creatures that had recently left the water. These arthropods lacked the skinny waist sported by modern spiders. Presumably, the spiders that later returned to a life aquatic were strongly drawn by something to eat there, or driven by unsafe conditions on land, says Geerat Vermeij, a paleobiologist and distinguished professor at UC Davis—because water would have presented major survival challenges.

“Since they depend on air so much, they are severely limited in whether they can do anything at all when they are submerged, other than just toughing it out,” Vermeij says. Newly aquatic spiders would have had to compete with predators better adapted to watery conditions, such as crustaceans, with competition particularly fierce in the oceans, Vermeij says. And if water floods a spider’s air-circulation system, it will die, so adaptations were obviously needed.

But spiders as a group already possess several water-friendly features, Crews suggests. They have waxy, water-repellent exteriors, often covered in hairs that conveniently trap air bubbles. Even having eight legs is helpful, Nelson says: Spiders can distribute their weight nicely while they skitter across a water surface, or use their octet of appendages to row along.

[Read: The spiders that choose death]

Some spiders take their aquatic adaptations to the next level, though. Consider the diving-bell spider, Argyroneta aquatica, an overachieving arachnid that is the only one known to do it all underwater: breathe, hunt, dine on insects and their larvae, and make spiderlings. Found in fresh water in Europe and parts of Asia, it spins a silken underwater canopy and brings air bubbles from the surface to its submerged home via its body hairs. When it goes out, it carries a smaller air bubble, like a little scuba tank, on its back.

Seashore spiders face particularly daunting conditions, says Nelson, who co-authored an article about adaptations of marine spiders for the 2024 Annual Review of Entomology. “There’s a splash zone,” she says. “It’s kind of a wild environment.” A spider might be baking in the hot sun one minute and drenched in chilly salt water the next. Some spiders migrate up and down their beaches with the tides; Nelson speculates that they monitor lunar cycles to anticipate when to move.

Other seashore spiders spin watertight nests where they hide out for hours while the tide is in. M. marina, for example, seeks seashells with nice, concave spaces in which to spin safe tents. Another spider, Desis marina, hides in holdfasts where bull kelp attaches to rocks, lining the holdfast’s interior with silk to create an air-filled pocket and staying submerged for as long as 19 days. D. marina emerges only when the tide is going out, to hunt for invertebrates like shrimp.

A spider that’s even occasionally submerged in salt water or that eats briny seafood will also have to maintain proper internal salt levels. “Presumably, they will be able to concentrate the salt somehow and then poo it out,” Nelson says. Scientists don’t know how marine spiders pull this off. And at least one intertidal-zone spider, Desis formidabilis of South Africa’s cape, comfortably maintains an interior salt concentration much like the crustaceans it eats, according to a 1984 study. (Freshwater species also probably require adaptations because their insides must stay saltier than their surroundings or food, Vermeij speculates.)

When a spider hides out with a limited air supply for days or weeks at a time, oxygen levels also may become a crucial issue. Intriguingly, researchers have identified gene variants within the oxygen-guzzling, energy-making mitochondria of aquatic spiders that may help them cope with low-oxygen environments. These changes mirror beneficial changes to mitochondrial genes in birds that live in high-altitude, low-oxygen environments.

In another study, researchers investigated the genes used in the silk glands of aquatic and land spiders. They found that water-spider silk seems to have a high proportion of water-repelling amino acids—which might also be an adaptation, they suggest.

But all the adaptations in the world might not be enough to save some water spiders. Nelson’s M. marina, for example, seems to be very particular about the beaches it occupies. The pebbles must be just right, not too big or small. If sea-level rise inundates M. marina’s beaches, it’s possible the spiders will have nowhere else to go, Nelson says. “So those spiders will be lost.”

Marco Isaia, an arachnologist at the University of Turin, in Italy, investigated the wetland habitats of the diving-bell spider and the fen raft spider, Dolomedes plantarius. As wetlands continue to disappear, the habitats available to each species will contract by more than 25 percent over a decade, and their ideal ranges will move northward, Isaia and colleagues predicted in a 2022 study. It would be difficult for the spiders to cross dry land for new wetlands, and Northern European winters might prove too cold anyway. “The loss and degradation of wetland habitats is expected to have serious impacts on their survival,” Isaia says, “and an increase in their extinction risk.”

Given these risks, some aquatic spiders might go the way of the dodo before science gets a handle on them. “I suspect in every rocky bed of beach or river, there are probably spiders that we just don’t know exist there,” Nelson says. “Because they’re hiding.”

Москва

Светлану Немоляеву госпитализировали с COVID-19 в Москве

Gunmen open fire and kill 4 people, including 3 foreigners, in Afghanistan's central Bamyan province

Glen Powell’s parents crash Texas movie screening to troll him

AML check crypto

Ballroom culture coming to the Long Beach Pride Festival

Ria.city






Read also

Wenceel Perez Player Props: May 21, Tigers vs. Royals

NY v Trump: Judge to consider defense motion to dismiss after prosecution rests case

Hellenic Bank champions green transition at Nicosia summit

News, articles, comments, with a minute-by-minute update, now on Today24.pro

News Every Day

$90,000 settlement approved in teen’s bullying lawsuit against LAUSD

Today24.pro — latest news 24/7. You can add your news instantly now — here


News Every Day

$90,000 settlement approved in teen’s bullying lawsuit against LAUSD



Sports today


Новости тенниса
WTA

Рахимова прошла во второй круг турнира WTA в Рабате на отказе Таунсенд



Спорт в России и мире
Москва

Футболисты ФК «Динамо Пушкино» заняли второе место в межрегиональном турнире Laffy Cup 2024



All sports news today





Sports in Russia today

Москва

Охрана и безопасность. Как роботы и дроны работают на спортивных объектах?


Новости России

Game News

Шапки женские на Wildberries — скидки от 398 руб. (на новые оттенки)


Russian.city


РПЛ

Проводы Джикии, дубль Сулейманова и парады голов в Нижнем Новгороде и Екатеринбурге: чем запомнился 29-й тур РПЛ


Губернаторы России
Спартак

Легенда "Спартака" Ловчев: немного перестал уважать Галицкого за отставку Ивича


«СВЯТОЙ ЛЕНИН» помогает В.В. Путину улучшить либо отменить налоги в обществе.

Поможет ли Кремль? Жене главного союзника Путина на Ближнем Востоке поставили страшный диагноз

Жители Люберец высадили кусты сирени на ул Мира в честь героев ВОВ

Шапки женские вязаные на Wildberries, 2024 — новый цвет от 392 руб. (модель 466)


Шнуров и Киркоров устроили перепалку из-за "Евровидения" на съёмках "Новой Фабрики звёзд"

«Считают каждую копейку»: Юрий Лоза рассказал о трудностях Максима Галкина* и Аллы Пугачевой в Израиле

Анастасия Волочкова рассказала в шоу Анфисы Чеховой на ТВ-3 о своём детстве

Пианист Мацуев о Станковиче в "Спартаке": опять тонко, опять иностранец


Экс‑теннисистка Джорджи обвиняется в краже мебели и ковров на €100 тысяч — СМИ

Теннисиста Медведева выбили из топ-4 ATP

Сумасшедший матч «Реала», Медведев опустился в рейтинге ATP. Главное к утру

Шнайдер вышла в финал турнира WTA-125 в Париже, обыграв Грачёву



«СВЯТОЙ ЛЕНИН» помогает В.В. Путину улучшить либо отменить налоги в обществе.

«СВЯТОЙ ЛЕНИН» УЛУЧШАЕТ ЗАКОНЫ, управляет патентами и улучшает командное планирование в целях учёта интереса всего народа.

В РМАТ ПРОШЕЛ I БИЗНЕС-ФОРУМ ВЫПУСКНИКОВ РМАТ 1999-2023 ГОДА ВЫПУСКА, ПОСВЯЩЕННЫЙ 55-ЛЕТНЕМУ ЮБИЛЕЮ АКАДЕМИИ

Творческие способы использования мозаики из стекла в дизайне интерьера


Лукашенко лоббирует интересы Алиева по изоляции Армении

Россия, Культура, Теат, Дети, ПДД: кукольным языком о дорожной безопасности детям показали в Ульгэре

«СВЯТОЙ ЛЕНИН» помогает В.В. Путину улучшить либо отменить налоги в обществе.

Маркетологи рассказали, что влияет на популярность компании в 2ГИС


Новый полноприводный Geely Atlas уже едет в Россию, названа цена

Сингл "Старик и воля" от СЭЙН и WIMMORTAL разорвал все чарты. Таких показателей не было с 2014 года в музыкальной индустрии

Йеллен: Минфин США продолжает изучать новые способы сокращения доходов России

С любовью к Родине: на Международной выставке-форуме “Россия” назвали имена лучших экскурсоводов-волонтеров



Путин в России и мире






Персональные новости Russian.city
Певец

Певец Эмин Агаларов дал первый концерт в России после трагедии в "Крокусе"



News Every Day

Ballroom culture coming to the Long Beach Pride Festival




Friends of Today24

Музыкальные новости

Персональные новости