I-Ectotherm ye-Thermoregulating

NguJake Zadik, owayesakuba ngumfundi wonxibelelwano kunye neThe Ocean Foundation ngoku ofunda eCuba.

Ke, uyabuza, yintoni i-ectotherm ye-thermoregulating? Igama elithi “ectotherm” libhekisa kwizilwanyana ezinobushushu bomzimba obunokuthelekiswa nendawo ezingqongileyo. Abakwazi ukulawula ngaphakathi ubushushu bomzimba wabo. Abantu bahlala bebhekisa kubo “njengegazi elibandayo”, kodwa eli gama lidla ngokulahlekisa abantu rhoqo. Ii-ectotherms ziquka ezirhubuluzayo, eziphila emhlabeni nasemanzini, kunye neentlanzi. Ezi zilwanyana zidla ngokuphumelela kwiindawo ezifudumeleyo. Imveliso yamandla ezinzileyo yegazi elishushu (isilwanyana esanyisayo) kunye nesilwanyana esinegazi elibandayo (isilwanyana esirhubuluzayo) njengomsebenzi wobushushu obuphakathi.

“I-Thermoregulating,” ibhekisela kumandla ezilwanyana ukugcina ubushushu bangaphakathi, kungajongwanga kangako ubushushu. Xa kubanda ngaphandle, ezi zinto ziphilayo ziyakwazi ukuhlala zishushu. Xa kushushu phandle, ezi zilwanyana ziyakwazi ukuzipholisa kwaye zingatshisi kakhulu. Ezi “zii-endotherm,” njengeentaka nezilwanyana ezanyisayo. Ii-Endotherms ziyakwazi ukugcina ubushushu bomzimba obungaguqukiyo kwaye zikwabizwa ngokuba zii-homeotherms.

Ke, ngeli xesha unokuqonda ukuba isihloko sale bhlog ngokwenene sichasa-into ephilayo engakwaziyo ukulawula ubushushu bomzimba wayo kodwa eneneni inamandla okulawula ubushushu bomzimba wayo? Ewe, yaye sisidalwa esikhethekileyo ngokwenene.

Le yinyanga yofudo lwaselwandle e-Ocean Foundation, yiyo loo nto ndikhethe ukubhala ngofudo lwaselwandle olune-leatherback kunye ne-thermoregulation yalo ekhethekileyo. Uphando lokulandela umkhondo lubonise olufudo ukuba luneendlela zokufuduka ukunqumla iilwandlekazi, kwaye lube lundwendwe olungaguqukiyo kuluhlu olubanzi lweendawo zokuhlala. Bafudukela kwisondlo esityebileyo, kodwa kumanzi abandayo kakhulu ukuya emantla njengeNova Scotia, eKhanada, kwaye baneendawo zokuhlala kumanzi ashushu kwiCaribbean. Ayikho enye i-reptile inyamezela ngokunyanisekileyo uluhlu olubanzi lweemeko zeqondo lokushisa-nditsho ngenkuthalo ngenxa yokuba kukho izirhubuluzi ezinyamezela ngaphantsi kwamaqondo okushisa angaphantsi kweqhwa, kodwa zenze njalo kwimeko yokulala. Oku kuye kwabangela umdla kwiingcali zezilwanyana kunye neengcali zebhayoloji yaselwandle iminyaka emininzi, kodwa kuye kwafunyaniswa kutshanje ukuba ezi zirhubuluzi zikhulu zilawula ngokwasemzimbeni ubushushu bazo.

…Kodwa zii-ectotherm, ziyenza njani le nto??…

Nangona ithelekiswa nobukhulu kwimoto encinci edibeneyo, ayinayo inkqubo yokufudumala eyakhiwe ngokusemgangathweni. Nangona kunjalo ubukhulu bazo budlala indima ebalulekileyo kulawulo lwazo lobushushu. Ngenxa yokuba makhulu kakhulu, ufudo lwaselwandle lunomhlaba ophantsi ukuya kutsho kumlinganiselo womthamo, ngoko ke ubushushu obuphambili bofudo butshintsha ngesantya esicotha kakhulu. Le nto ibizwa ngokuba yi-gigantothermy. Izazinzulu ezininzi zikholelwa ukuba oku kwakukwaluphawu lwezilwanyana ezininzi ezikhulu zangaphambili ngexesha lencopho yexesha lomkhenkce kwaye ekugqibeleni kwakhokelela ekubhangisweni kwazo njengoko amaqondo obushushu aqala ukunyuka (kuba ayengakwazi ukuphola ngokukhawuleza ngokwaneleyo).

Ufudo luphinde lisongelwe kumqolo omdaka we-adipose tissue, umaleko owomeleleyo okhuselayo wamafutha adla ngokufumaneka kwizilwanyana ezanyisayo. Le nkqubo inamandla okugcina ngaphezu kwe-90% yobushushu kumbindi wesilwanyana, ukunciphisa ilahleko yobushushu ngokusebenzisa iindawo ezivulekileyo. Xa kumanzi obushushu obuphezulu, kwenzeka into eyahlukileyo. I-Flipper stroke frequency iyancipha kakhulu, kwaye igazi lihamba ngokukhululekileyo ukuya emaphethelweni kwaye likhuphe ubushushu kwiindawo ezingagqunywanga kwizicubu ezikhuselayo.

Iifudo zaselwandle ze-leatherback ziphumelele kakhulu ekulawuleni ubushushu bomzimba wazo kangangokuba ziyakwazi ukugcina ubushushu bomzimba obungaguqukiyo obuyi-18 degrees ngaphezulu okanye ngaphantsi kweqondo lobushushu lendawo. Yinto engakholelekiyo leyo kangangokuba abanye abaphandi bayaphikisana kuba le nkqubo iphunyezwe ngokwe-metabolism, iifudo zaselwandle zaselwandle zineendothermic. Nangona kunjalo, le nkqubo ayiqhutywa ngokwe-anatomically, ke ngoko uninzi lwabaphandi bacebisa ukuba olu luguqulelo olunciphayo lwe-endothermy.

Iimfudo ze-Leatherback ayizizo zodwa ii-ectotherm zaselwandle ezinokuthi zibe nobu buchule. ityhuna yeBluefin inoyilo lomzimba olwahlukileyo olugcina igazi labo kumbindi wemizimba yazo kwaye zinenkqubo efanayo yokutshintshisa ubushushu yangoku kwi-leatherback. I-Swordfish igcina ubushushu entlokweni yayo ngokusebenzisa i-adipose emdaka efana ne-brown ukuze yandise umbono wabo xa iqubha kumanzi anzulu okanye abandayo. Zikwakho nezinye iingxilimbela zaselwandle eziphelelwa bubushushu xa zicotha, ezinjengokrebe omkhulu.

Ndicinga ukuba i-thermoregulation yinto nje enye enomdla kakhulu kwezi zidalwa zihle kakhulu ezinokungaphezulu kunokubona. Ukususela kumantshontsho amancinane aqanduselayo ukuya emanzini ukuya kutsho kwiinkunzi ezisoloko zixhakaxhaka, nakwiimazi ezalelayo ezibuyayo, kuninzi okungaziwayo ngazo. Abaphandi abaqinisekanga ukuba la mafudo ayichitha phi iminyaka embalwa yokuqala yobomi bawo. Iseyinto engaqondakaliyo ukuba ezi zilwanyana zihamba umgama zihamba njani ngendlela echane ngolo hlobo. Ngelishwa sifunda ngofudo lwaselwandle ngesantya esicotha kakhulu kunesantya sokuhla kwabemi bazo.

Ekugqibeleni kuya kufuneka ibe kukuzimisela kwethu ukukhusela into esiyaziyo, kunye nomdla wethu malunga nofudo lolwandle olungaqondakaliyo olukhokelela kwiinzame ezinamandla zolondolozo. Kuninzi okungaziwayo ngezi zilwanyana zibangel’ umdla yaye ukusinda kwazo kusongelwa kukulahlekelwa ziindlwane ezihlala elwandle, iplastiki nolunye ungcoliso elwandle, nokubanjiswa ngempazamo kwiminatha yokuloba neentambo ezinde. Sincede ku Isiseko soLwandle baxhase abo bazinikele kuphando ngofudo lwaselwandle kunye neenzame zolondolozo ngeNgxowa-mali yethu yoFudo lwaseLwandle.

Iingxelo:

1. Bostrom, uBrian L., kunye noDavid R. Jones. “Ukuzilolonga okufudumeleyo kwabadala be-Leatherback
2. Ufudo.”Uthelekiso lweBiyochemistry kunye neFiziyoloji Icandelo A: IMolekyuli kunye neFiziyoloji eDityanisiweyo 147.2 (2007): 323-31. Shicilela.
3. UBostrom, uBrian L., T. Todd Jones, uMervin Hastings, kunye noDavid R. Jones. "Ukuziphatha kunye nePhysiology: iSicwangciso soThermal seLeatherback Turtles." U-Ed. Lewis George Halsey. PLoS ONE 5.11 (2010): E13925. Shicilela.
4. UGoff, uGregory P., kunye noGarry B. Stenson. "I-Brown Adipose Tissue kwi-Leatherback Sea Turtles: I-Thermogenic Organ kwi-Endothermic Reptile?" eCopeia 1988.4 (1988): 1071. Shicilela.
5. UDavenport, J., J. Fraher, E. Fitzgerald, P. Mclaughlin, T. Doyle, L. Harman, T. Cuffe, kunye noP. Dockery. "Utshintsho lwe-Ontogenetic kuLwakhiwo lweTracheal luququzelela ukuntywila ngokunzulu kunye naManzi abandayo ekuFundeni kwiiFudo zaseLwandle eziDala ze-Leatherback." Ijenali ye-Biology yovavanyo 212.21 (2009): 3440-447. Shicilela
6. UPenick, uDavid N., uJames R. Spotila, uMichael P. O'Connor, u-Anthony C. Steyermark, uRobert H. George, uChristopher J. Salice, noFrank V. Paladino. "Ukuzimela kwe-Thermal ye-Muscle Tissue Metabolism kwi-Leatherback Turtle, i-Dermochelys Coriacea." Uthelekiso lweBiyochemistry kunye neFiziyoloji Icandelo A: IMolekyuli kunye neFiziyoloji eDityanisiweyo 120.3 (1998): 399-403. Shicilela.