02945nas a2200217 4500008004100000022001400041245006300055210006200118260001600180300000700196490000700203520232200210653001502532653002502547653001502572100003002587700002202617700002002639700002502659856004302684 2022 eng d a2075-445000aHow Did Seal Lice Turn into the Only Truly Marine Insects?0 aHow Did Seal Lice Turn into the Only Truly Marine Insects cDec-31-2021 a460 v133 a

Simple Summary: Sucking lice are permanent and obligate ectoparasites throughout their whole life cycle. Echinophthiriids escorted their mammal hosts during their passage from fully terrestrial to amphibian life. Seal lice synchronize their reproduction cycle with that of their mammalian hosts. Echinophthiriids tolerate long immersion periods and extreme hydrostatic pressures. Diving lice can reach kilometers under the surface and survive, during the months their hosts remain in the open ocean. In the present work, we describe and discuss how some of these adaptations allow seal lice to cope with the amphibious habits of their hosts and how they can help us to understand why insects are so rare in the ocean

Abstract: Insects are the most evolutionarily and ecologically successful group of living animals, being present in almost all possible mainland habitats; however, they are virtually absent in the ocean, which constitutes more than 99% of the Earth’s biosphere. Only a few insect species can be found in the sea but they remain at the surface, in salt marshes, estuaries, or shallow waters. Remarkably, a group of 13 species manages to endure long immersion periods in the open sea, as well as deep dives, i.e., seal lice. Sucking lice (Phthiraptera: Anoplura) are ectoparasites of mammals, living while attached to the hosts’ skin, into their fur, or among their hairs. Among them, the family Echinophthiriidae is peculiar because it infests amphibious hosts, such as pinnipeds and otters, who make deep dives and spend from weeks to months in the open sea. During the evolutionary transition of pinnipeds from land to the ocean, echinophthiriid lice had to manage the gradual change to an amphibian lifestyle along with their hosts, some of which may spend more than 80% of the time submerged and performing extreme dives, some beyond 2000 m under the surface. These obligate and permanent ectoparasites have adapted to cope with hypoxia, high salinity, low temperature, and, in particular, conditions of huge hydrostatic pressures. We will discuss some of these adaptations allowing seal lice to cope with their hosts’ amphibious habits and how they can help us understand why insects are so rare in the ocean.

10aadaptation10aExtreme environments10aPinnipedia1 aLeonardi, María, Soledad1 aCrespo, José, E.1 aSoto, Florencia1 aLazzari, Claudio, R. uhttps://www.mdpi.com/2075-4450/13/1/4601429nas a2200205 4500008004100000022001500041245008900056210006900145260001400214300000900228490000700237520078200244653003901026653001901065100003001084700002201114700002001136700002501156856004201181 2021 eng d a2504-3900 00aDiving Lice: The Exception to the Rule That There Are No Insects in the (Deep) Ocean0 aDiving Lice The Exception to the Rule That There Are No Insects  cJuly 2021 a6 pp0 v683 a

Insects are present in virtually all possible habitats on the mainland but virtually absent in the ocean which constitutes 90% of the biosphere. Only a few species are present in the sea, but remaining at the surface, salt marshes, estuaries, or shallow waters. Remarkably, a group of species manages to endure long immersion periods in the open sea, as well as deep dives, i.e. seal lice. We discuss here some of the adaptations that allow seal lice to cope with the amphibious habits of their
hosts and how they can help understanding why are insect so rare in the ocean

Paper presented virtually at at the 1st International Electronic Conference on Entomology (IECE 2021), 1–15 July 2021; Available online https://sciforum.net/paper/view/10543

10aAdaptation to extreme environments10aMarine insects1 aLeonardi, María, Soledad1 aCrespo, José, E.1 aSoto, Florencia1 aLazzari, Claudio, R. uhttps://sciforum.net/paper/view/1054303508nas a2200229 4500008004100000022001400041245008400055210006900139260001200208300001500220520277800235653002303013653002503036653001903061100003003080700002203110700002003132700002203152700001903174700002503193856006003218 2020 eng d a0022-094900aUnder pressure: the extraordinary survival of seal lice in the depth of the sea0 aUnder pressure the extraordinary survival of seal lice in the de c07-2020 ajeb.2268113 a

Lice from pinnipeds – sea lions, seals and walruses – are the only insects capable of surviving marine dives. Throughout their evolutionary history, they have adapted to tolerate hypoxia, high salinity, low temperature and, in particular, to tolerate conditions of high hydrostatic pressure. To understand the limits of the capacity of lice to survive during host deep dives, we conducted a series of controlled experiments in the laboratory. We collected lice from elephant seals and submitted the different life stages to high pressure conditions. Lice were first exposed to one of four hydrostatic pressures: 30, 80, 150 or 200 kg cm−2. They were then exposed a second time to higher or lower hydrostatic pressure conditions to test for the impact of the first experience, which could either be deleterious or trigger physiological adaption, allowing them a better tolerance to high pressure. We found that lice from elephant seals can tolerate hydrostatic pressures higher than 200 kg cm−2 (close to 200 atm), which is equivalent to 2000 m depth. Adults exhibited lower recovery times than nymphs after immersion at high hydrostatic pressure. Our findings show that lice have developed unique adaptations to endure extreme marine conditions. We discuss these extreme performances in relation to the morphological characteristics and physiological responses to diving in these insects.

In addition, you can view the media coverage of the research publicaiion in the following media news

El poder de lo minúsculo by CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas) 19-8-2020 edition - https://www.conicet.gov.ar/el-poder-de-lo-minusculo/ and http://phthiraptera.info/node/95123

An exception to the rule that there are no marine insects by The Economist, Science & Technology 6-8-2020 edition - https://www.economist.com/science-and-technology/2020/08/06/an-exception-to-the-rule-that-there-are-no-marine-insects

Des poux sous haute pression by Pour la Science 1-9-2020 edition  - https://www.pourlascience.fr/sd/biologie-animale/des-poux-sous-haute-pression-19974.php and http://phthiraptera.info/node/95122

You Can’t Escape Lice, Even 6,500 Feet Below the Ocean by New Tork Times 26-8-2020 edition - https://www.nytimes.com/2020/08/26/science/lice-elephant-seals.html and http://phthiraptera.info/node/95102

Intrepid lice survive extreme pressure when hitching rides on elephant seals, INSIDE JEB- https://jeb.biologists.org/content/223/17/jeb234260 and http://phthiraptera.info/node/95124

 

 

10aDiving adaptations10aExtreme environments10aMarine insects1 aLeonardi, María, Soledad1 aCrespo, José, E.1 aSoto, Florencia1 aVera, Ricardo, B.1 aRua, Julio, C.1 aLazzari, Claudio, R. uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.226811