Tardigrade

Tardigrade wanda kuma ake kira da bear na ruwa, wani nau'in ƙananan invertebrates ne masu rayuwa kyauta waɗanda ke cikin nau'in arthropod. Wannan zamanin ya dimauta masana kimiyya tsawon shekaru tare da ikon rayuwa a cikin duk abin da ya faru kawo yanzu - har ma a sararin samaniya. Daga farfajiyar teku har zuwa dutsen dazuzzuka, daga tundra na Antarctica zuwa saman dutsen mai fitad da wuta, tardigrades suna ko'ina.

Asalin jinsin da bayanin

Hotuna: Tardigrade

An gano shi a cikin 1773 ta Johann August Ephraim Gose, masanin kimiyyar dabbobin Jamusawa, tardigrades sune micrometazoids na arthropod tare da nau'i biyu na paws (lobopods), musamman sanannun ikonsu na rayuwa a cikin yanayi daban-daban. Tardigrades ana daukar su dangi ne na arthropods (misali kwari, crustaceans).

Zuwa yau, bincike ya gano manyan aji uku na nau'ikan tardigrades. Kowane ɗayan azuzuwan ya ƙunshi umarni da yawa, wanda, bi da bi, ya ƙunshi iyalai da yawa da dangi.

Bidiyo: Tardigrade

Sabili da haka, nau'in tardigrade ya ƙunshi ɗari da yawa (sama da 700) sanannun nau'ikan, waɗanda aka kasafta su cikin rukunan masu zuwa:

• aji Heterotardigrada. Idan aka kwatanta da sauran biyun, wannan ajin shine mafi yawan aji a cikin nau'in tardigrade. An sake raba shi zuwa umarni biyu (Arthrotardigrada da Echiniscoide) sannan kuma cikin iyalai da suka haɗa da Batillipedidae, Oreellidae, Stygarctidae, da Halechiniscidae, da sauransu. Wadannan iyalai sun kasu kashi fiye da hamsin;
• ajin Mesotardigrada. Idan aka kwatanta da sauran azuzuwan, wannan rukunin ya kasu kashi ɗaya ne kawai (Thermozodia), iyali (Thermozodidae) da jinsin daya (Thermozodium esakii). An samo Thermozodium esakii a cikin ruwan bazara mai zafi a Japan, amma babu wani nau'in ajin da aka gano;
• Ajin Eutardigrada ya kasu kashi biyu, wadanda suka hada da Parachela da Apochela. An sake raba umarnin biyu zuwa gida shida, wadanda suka hada da Mineslidae, Macrobiotidae, Hypsibidae, Calohypsibidae, Eohypsibidae, da Eohypsibidae. Wadannan iyalai an kara raba su zuwa sama da mutum 35 da jinsuna daban-daban.

Bayyanar abubuwa da fasali

Hotuna: Yaya fasalin fasalin kama

Abubuwa na yau da kullun na tardigrades sune kamar haka:

• suna da daidaito iri-iri;
• suna da jiki mai motsi (amma sukan daidaita);
• suna da tsawon micrometer 250 zuwa 500 (manya). Koyaya, wasu na iya yin girma zuwa milimita 1.5;
• sun bambanta da launi: ja, rawaya, baƙi, da dai sauransu;
• ana samun numfashi ta hanyar yadawa;
• kwayoyin halitta ne da yawa.

Jikinsu ya kasu kashi da yawa: jiki, ƙafafu, ɓangaren kai. Tardigrades suna da tsarin narkewa, baki, tsarin juyayi (da kuma ingantacciyar kwakwalwa mai girma), tsokoki, da idanu.

Gaskiya mai ban sha'awa: A shekara ta 2007, an ƙaddamar da tardigrades masu bushewa zuwa zagaye kuma an nuna su cikin yanayi da hasken rana na kwanaki 10. Bayan dawowarsu Duniya, fiye da kashi biyu bisa uku an samu nasarar dawo dasu. Yawancinsu sun mutu ba da daɗewa ba, amma har yanzu suna iya haifuwa tukunna.

Wasu halayen da ke haɗuwa da aji Heterotardigrada sun haɗa da honducts, hanyoyin cephalic, da ƙafafun mutum a ƙafa.

Sauran halaye sun haɗa da masu zuwa:

• kan nonon azanci da kashin baya;
• abin wuya a kafafu na baya;
• yanka mai kauri;
• alamu na pore da suka bambanta tsakanin jinsuna.

Halaye na ajin Mesotardigrada:

• kowane kafa yana da fika shida;
• Thermozodium esakii shine matsakaici tsakanin membobin Heterotardigrada da Eutardigrada;
• spines da fika suna kama da na jinsin Heterotardigrada;
• macroplakoids ɗinsu suna kama da waɗanda aka samu a Eutardigrada.

Wasu daga halayen Eutardigrada sun haɗa da:

• idan aka kwatanta da sauran azuzuwan biyu, membobin ajin Eutardigrada ba su da kayan aiki na gefe;
• suna da yanka mai laushi;
• ba su da faranti na dorsal;
• Bude buhu-buzu a cikin dubura;
• suna da fika biyu.

A ina tardigrade yake rayuwa?

Photo: Dabba tardigrade

A zahiri, tardigrades halittun ruwa ne, kasancewar ruwa yana samar da kyakkyawan yanayi don aiwatarwa kamar musayar gas, haifuwa da haɓaka. A saboda wannan dalili, galibi ana samun tardigrades masu aiki a cikin ruwan teku da ruwa mai kyau, haka kuma a cikin mahalli na ƙasa tare da ƙaramin ruwa.

Kodayake ana la'akari da na cikin ruwa, ana iya samun tardigrades a wasu wurare da yawa, gami da dunes, ƙasa, duwatsu, da rafuffuka, da sauransu. Zasu iya rayuwa a cikin fina-finai na ruwa akan laushi da kankara kuma saboda haka galibi ana samun su a cikin waɗannan ƙwayoyin.

Hakanan ƙwai, kumbura, da ɓarna na tardigrades suma ana iya busa su cikin yanayi daban-daban, wanda ke bawa allowingan Adam damar mallake sabbin mahalli. Dangane da bincike, an gano tardigrades a wurare daban-daban kamar su tsibirai masu aman wuta, wanda hakan shaida ce cewa iska da dabbobi irin su tsuntsaye suna yaduwa da yada kwayoyin halitta.

Gaskiya mai ban sha'awa: Baya ga mahalli da muhallai masu ƙarancin da mara kyau, an kuma gano tardigrades a cikin mawuyacin yanayi, kamar mawuyacin yanayi (ƙasa da -80 digiri Celsius). Dangane da ikon su na rayuwa har ma da haihuwa a karkashin waɗannan yanayi, ana samun tardigrades a kusan dukkanin mahalli a duniya.

An bayyana Tardigrades a matsayin polyextremophiles saboda ikonsu na rayuwa a cikin tsauraran muhalli da dama. Wannan ya zama ɗayan halayen halayen su mafi mahimmanci kuma ɗayan mahimmancin binciken nau'ikan nau'ikan.

Yanzu kun san inda aka samo shi da kuma yadda tardigrade yake a ƙarƙashin microscope. Bari muga me wannan halittar take ci.

Menene tardigrade ke ci?

Photo: Tardigrade halitta

Tardigrades suna ciyar da ruwa mai salula ta hanyar huda ganuwar kwayar halitta tare da salon salon baka. Abincin sun hada da kwayoyin cuta, algae, protozoa, bryophytes, fungi, da kuma lalacewar tsirrai. Suna tsotse ruwan 'ya'yan itace daga algae, lichens da moss. An san cewa manyan nau'ikan suna ciyar da protozoa, nematodes, rotifers da ƙananan tardigrades.

A bakinsu, tardigrades suna da stilettos, waɗanda asalinta ƙananan ƙananan hakora ne masu kaifi waɗanda ake amfani da su don huda tsire-tsire ko ƙananan invertebrates. Suna ba da izinin ruwa ya wuce yayin huda su. Tardigrades suna ciyar da waɗannan ruwan ta hanyar shan su ta amfani da tsokoki na tsotsa na musamman a cikin maƙogwaron su. Ana maye gurbin salo lokacin da suke narkewa.

A wasu yankuna, tardigrades na iya zama babban mabukaci na nematodes, wanda ke tasiri ƙimar yawan al'ummomin su. Wasu nau'ikan zasu iya daukar nau'in kwayar halitta Pyxidium tardigradum. Yawancin jinsuna masu lalacewa waɗanda ke rayuwa a cikin yanayin mossy suna ɗaukar ƙwayoyin fungal.

Gaskiya mai ban sha'awa: Wasu nau'in tardigrades na iya wucewa ba tare da abinci ba sama da shekaru 30. A wannan lokacin, sun bushe kuma sun yi barci, sa'annan za su iya sake shayarwa, su ci wani abu kuma su ninka. Idan tardigrade ya zama mara ruwa kuma ya rasa kashi 99% na abinda yake cikin ruwa, ana iya kusan dakatar da ayyukan rayuwarsa tsawon shekaru kafin ya dawo da rai.

A cikin sel din tardigrades masu bushewar jiki, wani nau'in sunadaran da ake kira "tardigrade-takamaiman aikin rashin aiki" ya maye gurbin ruwa. Wannan yana haifar da wani abu mai gilashi wanda yake kiyaye tsarin kwayar halitta.

Fasali na ɗabi'a da salon rayuwa

Photo: Tardigrade a ƙarƙashin madubin hangen nesa

Yayinda suke aiki a yanayi mai kyau, wadanda suka koma baya sun dauki wasu dabaru da zasu basu damar rayuwa.

Wadannan dabarun sanannun sanannun suna hutawar cryptobiosis kuma sun haɗa da:

• anoxybiosis - yana nufin yanayin yanayin kwayar halitta wanda karancinsa ko kuma rashin isashshen oxygen ya motsa tsakanin tardigrades na cikin ruwa. Lokacin da matakan oxygen ke da ƙasa ƙwarai, abin da ke faruwa a baya zai zama mai ƙarfi, mara motsi, da tsawaitawa. Wannan yana ba su damar rayuwa daga fewan awanni kaɗan (don ƙananan tardigrades na ruwa) zuwa kwanaki da yawa ba tare da iskar oxygen ba kuma ƙarshe suyi aiki lokacin da yanayi ya inganta;
• Cryobiosis wani nau'i ne na cryotobiosis wanda ƙananan yanayin zafi ke shafar shi. Lokacin da yanayin zafin jiki ya daskarewa zuwa daskarewa, sai masu jinkiri suka amsa ta hanyar yin ganga mai kama da ganga don kare membrane;
• osmobiosis - a cikin maganan ruwa mai karfi tare da ionic ƙarfi (kamar yawan gishiri), wasu ƙwayoyin jiki ba za su iya rayuwa ba don haka su mutu. Koyaya, adadi mai yawa na tardigrades da aka samo a cikin ruwa mai kyau da wuraren zama na duniya sun tsira a cikin wani nau'i na cryptobiosis da aka sani da osmobiosis;
• anhydrobiosis amsawa ce ta rayuwa ga asarar ruwa ta hanyar ƙafewa. Ga halittu daban-daban, ruwa yana da mahimmanci don aiwatarwa kamar musayar gas da sauran hanyoyin ciki. Ga yawancin tardigrades na ruwa, rayuwa ba zata yuwu ba lokacin rashin ruwa. Koyaya, don adadi mai yawa na Eutardigrada, rayuwa a ƙarƙashin waɗannan sharuɗɗan ana samun ta ne ta hanyar kwangila da janye kai da ƙafafu. Kwayoyin halitta sun zama ganga wadanda zasu iya rayuwa bayan sun bushe.

Tsarin zamantakewa da haifuwa

Hotuna: Tardigrade

Sake haifuwa da sake zagayowar rayuwa tsakanin masu jujjuyawa sun dogara sosai da mazauninsu. Ganin cewa rayuwar waɗannan ƙwayoyin cuta yawanci yana tattare da rashin aiki da rashin aiki lokaci-lokaci, masu binciken sun ƙarasa da cewa yana da mahimmanci don saurin haifuwa lokacin da yanayi ya dace.

Dogaro da mahalli, tardigrades na iya hayayyafa ba tare da wani lokaci ba (takin kai) a cikin wani tsari da aka sani da parthenogenesis, ko kuma jima'i, lokacin da maza ke yin ƙwai (amphimixis).

Samun jima'i a cikin tardigrades ya zama ruwan dare tsakanin jinsunan dioecious (maza da mata tare da al'aurarsu). Mafi yawan waɗannan kwayoyin ana samun su a cikin yanayin ruwa don haka suke ninkawa a cikin yanayin ruwan.

Kodayake fasali da girma (ilimin halittar jikin mutum) na tardigrade gonads sun dogara ne da jinsi, jinsi, shekaru, da dai sauransu na ƙwayoyin halitta, nazarin microscopic ya bayyana abubuwan al'aura masu zuwa a cikin maza da mata:

Namiji:

• ofarƙwarar vas deferens buɗe cikin cloaca (hind gut);
• ƙwayoyin ciki na ciki.

Mace da hermaphrodite:

• vidunƙun duwatsu biyu waɗanda suka buɗe cikin cloaca;
• seminal tasoshin (a cikin Heterotardigrada);
• spermatheca na ciki (a cikin Eutardigrada).

Yayinda akeyin jima'i tsakanin wasu membobin aji Heterotardigrada da Eutardigrada, kwan mace suna haduwa kai tsaye ko kuma kai tsaye. Yayin da ake yin shigar da kai tsaye ta hanyar jima'i, jinkirin namiji ya sanya maniyyi a cikin kwayar halittar mace, wanda ke ba da damar daukar maniyyin zuwa cikin kwan don yin takin.

Yayin da ake hada mace kai tsaye, namiji yana sanya maniyyi a jikin mace yayin da mace ta narke. Lokacin da mace ta zubar da abin yanka, ƙwai sun riga sun haɗu kuma suna haɓaka cikin lokaci. Yayin narkar da kwalliyar, mace tana zubar da yankan ka, da kuma wasu sassa kamar ƙafafu.

Dogaro da jinsin, ƙwai ko dai sun haɗu a ciki (alal misali, a cikin L. granulifer, inda kwanciya ke faruwa), a waje (a yawancin Heterotardigrada), ko kuma kawai a sake su a waje, inda suke ci gaba ba tare da hadi ba.

Kodayake kulawar kwai na iyaye ba safai ba, an lura da shi a cikin nau'ikan da yawa. Kwanansu suna kasancewa a haɗe da jelar mace, don haka tabbatar da cewa mace tana kula da ƙwan kafin su ƙyanƙyashe.

Abokan gaba na tardigrades

Hotuna: Yaya fasalin fasalin kama

Ana iya ɗaukar masu farautar tardigrades nematodes, wasu tardigrades, kaska, gizo-gizo, wutsiyoyi da larvae na kwari. Parasitic protozoa da fungi galibi suna cutar da tardigrades. Har ila yau, masu lalata halittu kamar su ruwan kwandon ruwa, tsutsotsi na duniya da kuma cututtukan mahaifa suna kashe yawan wadannan dabbobin.

Hakanan, tardigrades suna amfani da kayan aikinsu don ciyarwa akan ƙwayoyin cuta ko ƙwayoyin cuta, ciki har da ƙwayoyin cuta, algae, protozoa, da sauran meiofauna.

Kayan aikin buccal ya kunshi bututun buccal, kayan salo na huda, da kuma pharynx masu tsotsan jijiyoyin jiki. Abubuwan da ke cikin hanji galibi suna ɗauke da chloroplasts ko wasu ƙwayoyin ƙwayoyin algae, mosses ko lichens.

Yawancin nau'ikan microbiota na duniya sun yi kokarin cin ganyayyaki, nematodes, rotifers, da ƙananan Eutardigrades (kamar su Diphascon da Hypsibius), har ma suna tsotsa a cikin jikin duka. A cikin muƙamuƙin waɗannan ƙarshen tardigrades masu ƙarancin ƙarfi, an sami rotifer, ƙafafun tardigrades da bakinsu na magana. An ɗauka cewa nau'in kayan masarufin yana da alaƙa da nau'in abincin da aka cinye, duk da haka, ba a san komai game da takamaiman buƙatun abinci mai gina jiki na halittun ruwa ko tsirrai.

Gaskiya mai ban sha'awa: Duk da cewa tardigrades suna iya tsayayya da yanayin sararin samaniya, yanayin ƙarancin yanayin zafi da kuma babban yanayin da aka rufe shi, zasu iya rayuwa kusan aƙalla shekaru 2.5.

Yawan jama'a da matsayin jinsin

Photo: Dabba tardigrade

Yawan tardigrades yana da matukar canzawa, amma ba a san mafi ƙarancin yanayi ko yanayin da ya dace don haɓaka yawan jama'a ba. Canje-canje a cikin yawan adadin tardigrades an danganta su da yanayin mahalli daban-daban, gami da yanayin zafi da zafi, gurɓatar iska, da wadatar abinci. Mahimmancin bambance-bambance a cikin yawan yawan jama'a da bambancin jinsuna na faruwa a kusa da juna, da alama microbits iri ɗaya ne.

Daidaita yanayin yanayi na waje da yawa, yawan jinsi da nau'ikan tardigrades sun bayyana. Zasu iya rayuwa cikin ganga har tsawon shekaru ko ma shekarun da suka gabata don rayuwa cikin yanayin bushewa. Bugu da kari, samfurorin da aka gudanar na tsawon kwanaki takwas a cikin yanayi, aka sauya su na tsawon kwanaki uku a cikin sinadarin helium a yanayin zafin dakin, sa’annan a gudanar da su na wasu awanni a -272 ° C, sun farfado lokacin da aka kawo su cikin yanayin dakin. ... 60% na samfuran da aka adana na watanni 21 a cikin iska mai iska a -190 ° C suma sun rayu. Hakanan Tardigrades ana iya yada su ta iska da ruwa.

Gaskiya mai ban sha'awa: Tardigrades suna rayuwa cikin yanayin da zasu iya lalata yawancin sauran kwayoyin. Suna yin hakan ta hanyar cire ruwa daga jikinsu da kuma samar da mahaɗan da ke rufewa da kare tsarin kwayar halittarsu. Halittu na iya kasancewa a cikin wannan yanayin da ake kira da tuna tsawon watanni da yawa kuma har yanzu suna rayarwa a gaban ruwa.

Shekaru aru-aru, tardigrades sun rikita masana kimiyya kuma suna ci gaba da yin hakan. A shekarar 2016, masana kimiyya sun yi nasarar dawo da dusar kankara wacce ta daskarewa fiye da shekaru talatin, kuma suka gano sabbin ka'idojin rayuwar dabbobi dangane da yanayin zafi.

A matsayinka na jinsin duniya, babu wata damuwa da cewa yan tardigrad na cikin hatsari, kuma a yanzu haka babu wasu tsare tsaren kiyayewa wadanda suka ta'allaka kan kowane takamaiman jinsin da bai dace ba. Koyaya, akwai shaidar cewa gurbatar yanayi na iya yin mummunan tasiri ga al'ummominsu, kamar yadda rashin iska mai kyau, ruwan sama na ruwa da kuma ƙarfe mai ƙarfi a cikin ƙauyukan bryophyte sun haifar da raguwa a wasu alumomin.

Tardigrade - wataƙila mafi kyawun halitta a duniya. Babu wata halitta a doran kasa, ko wataqila a cikin sararin samaniya, da ta shude tsawonta. Ba za a iya isa ga tafiye-tafiye na sararin samaniya ba kuma mai wadatar rai don rayuwa shekaru da yawa a cikin hibernation, tardigrade na iya wuce mu duka da sauƙi.

Ranar bugawa: 09/30/2019

Ranar da aka sabunta: 11.11.2019 a 12:15