I-Ectotherm ye-Thermoregulating

Ibhalwe ngu-Jake Zadik, owayengumfundi wezokuxhumana e-The Ocean Foundation manje ofunda eCuba.

Ngakho-ke, uyabuza, iyini i-ectotherm ye-thermoregulating? Igama elithi “ectotherm” libhekisela ezilwaneni ngokuvamile ezinezinga lokushisa lomzimba eliqhathaniswa nendawo ezizungezile. Abakwazi ukulawula ngaphakathi izinga lokushisa lomzimba wabo. Abantu bavame ukubhekisela kubo ngokuthi "igazi elibandayo", kodwa leli gama livame ukukhohlisa abantu kaningi. Ama-ectotherm ahlanganisa izilwane ezihuquzelayo, eziphila emanzini nasezweni, nezinhlanzi. Lezi zilwane zivame ukuchuma ezindaweni ezifudumele. Ukukhipha amandla okuqhubekayo kwesilwane esinegazi elifudumele (isilwane esincelisayo) kanye nesilwane esinegazi elibandayo (isilwane esihuquzelayo) njengomsebenzi wokushisa okuyisisekelo.

Igama elithi “thermoregulating,” libhekisela ekhonweni lezilwane lokulondoloza izinga lokushisa langaphakathi, ngaphandle kokunaka izinga lokushisa. Uma kubanda ngaphandle, lezi zinambuzane ziyakwazi ukuhlala zifudumele. Uma kushisa ngaphandle, lezi zilwane zinamandla okuzipholisa futhi zingashisi ngokweqile. Lawa “ama-endotherm,” njengezinyoni nezilwane ezincelisayo. Ama-Endotherm anamandla okugcina izinga lokushisa lomzimba elingashintshi futhi abizwa nangokuthi ama-homeotherm.

Ngakho-ke, ngalesi sikhathi ungase ubone ukuthi isihloko sale bhulogi empeleni siwukuphikisana—into ephilayo engakwazi ukulawula izinga lokushisa lomzimba wayo kodwa empeleni inamandla okulawula ngokukhuthele izinga lokushisa lomzimba wayo? Yebo, futhi iyisidalwa esikhetheke kakhulu ngempela.

Le yinyanga yofudu lwasolwandle e-The Ocean Foundation, yingakho ngikhethe ukubhala ngofudu lwasolwandle oluyi-leatherback kanye ne-thermoregulation yalo ekhethekile. Ucwaningo lokulandela ngomkhondo lubonise lolu fudu ukuthi lunemizila yokufuduka lunqamula izilwandle, futhi lube izivakashi ezihlala njalo ezindaweni eziningi zokuhlala. Zifudukela emanzini acebile, kodwa abandayo kakhulu enyakatho njengeNova Scotia, eCanada, futhi zinezindawo zokuzalela emanzini ashisayo kulo lonke elaseCaribbean. Asikho esinye isilwane esihuquzelayo esibekezelela ngenkuthalo ububanzi obunjalo bezimo zokushisa—ngisho ngenkuthalo ngoba kunezilwane ezihuquzelayo ezibekezelela amazinga okushisa angaphansi kweqhwa, kodwa zenza kanjalo esimweni sokulala. Lokhu kuye kwabathakazelisa izazi zezifo zezilwane kanye nezazi zezinto eziphilayo zasolwandle iminyaka eminingi, kodwa kusanda kutholwa ukuthi lezi zilwane ezinkulu ezihuquzelayo zilawula izinga lokushisa kwazo ngokomzimba.

…Kodwa ama-ectotherm, akwenza kanjani lokhu??…

Naphezu kokuqhathaniswa ngosayizi nemoto encane ehlangene, abanayo isistimu yokushisa eyakhelwe ngaphakathi efika ejwayelekile. Nokho ubukhulu bazo budlala indima ebalulekile ekulawuleni izinga lokushisa kwazo. Ngenxa yokuthi zinkulu kakhulu, izimfudu zasolwandle zinendawo ephansi nesilinganiso somthamo wevolumu, ngaleyo ndlela izinga lokushisa eliwumgogodla wofudu liyashintsha ngenani eliphansi kakhulu. Lesi simo sibizwa ngokuthi "gigantothermy." Ososayensi abaningi bakholelwa ukuthi lokhu futhi kwakuyisici sezilwane eziningi ezinkulu zangaphambi komlando ngesikhathi somvuthwandaba weqhwa futhi kwagcina kuholele ekushabalaleni kwazo njengoba amazinga okushisa eqala ukwenyuka (ngoba ayengakwazi ukuphola ngokushesha ngokwanele).

Ufudu luphinde lugoqwe ngesicubu se-adipose esinsundu, ungqimba oluqinile lwamafutha avame ukutholakala ezilwaneni ezincelisayo. Le sistimu inamandla okugcina ukushisa okungaphezu kuka-90% enkabeni yesilwane, inciphisa ukulahlekelwa ukushisa ezindaweni eziveziwe. Lapho emanzini okushisa okuphezulu, kwenzeka okuphambene. Imvamisa ye-Flipper stroke yehla kakhulu, futhi igazi lihamba ngokukhululekile emaphethelweni futhi lixosha ukushisa ezindaweni ezingamboziwe kusicubu se-insulating.

Izimfudu zasolwandle ze-leatherback ziphumelela kakhulu ekulawuleni izinga lokushisa lomzimba wazo kangangokuthi zinamandla okugcina izinga lokushisa lomzimba elingashintshi libe ngu-18 degrees ngaphezu noma ngaphansi kwezinga lokushisa elizungezile. Kuyamangaza lokho kangangokuba abanye abacwaningi bayaphikisana ngoba le nqubo ifinyelelwa ngokusebenza kwe-metabolism ye-leatherback yasolwandle empeleni i-endothermic. Kodwa-ke, le nqubo ayenziwa ngokuzenzakalelayo, ngakho-ke abacwaningi abaningi baphakamisa ukuthi lena inguqulo encane ye-endothermy.

Izimfudu ze-Leatherback akuzona kuphela ama-ectotherm olwandle angaba naleli khono. I-Bluefin tuna inomklamo womzimba oyingqayizivele ogcina igazi layo lisemnyombweni womzimba wayo futhi inesistimu yesishintshi sokushisa yamanje ephikisayo efana ne-leatherback. I-Swordfish igcina ukushisa ekhanda layo ngokusebenzisa ungqimba lwethishu ye-adipose ensundu efanayo evikelayo ukuze yandise ukubona kwayo lapho ibhukuda emanzini ajulile noma abandayo. Kukhona nezinye iziqhwaga zasolwandle ezilahlekelwa ukushisa lapho zihamba kancane, njengoshaka omhlophe.

Ngicabanga ukuthi i-thermoregulation iyisici esisodwa esithakazelisa ngokumangalisayo salezi zidalwa ezinhle ngokubabazekayo ezinokuningi kakhulu kunalokho okubonwa ngamehlo. Kusukela emazinyaneni amancanyana aya emanzini kuya kweyeduna ehlala njalo kanye nasezinsikazini ezizalela ezibuyayo, okuningi ngawo akukaziwa. Abacwaningi abaqiniseki ukuthi lezi zimfudu zichitha kuphi iminyaka embalwa yokuqala yokuphila kwazo. Kuseyindida ukuthi lezi zilwane ezihamba ibanga elide zihamba kanjani ngendlela enembe kangaka. Ngeshwa sifunda ngezimfudu zasolwandle ngezinga elihamba kancane kunezinga lokuncipha kwenani labantu bazo.

Ekugcineni kuzofanele kube ukuzimisela kwethu ukuvikela esikwaziyo, kanye nelukuluku lethu mayelana nezimfudu zasolwandle ezingaqondakali eziholela emizamweni eqinile yokongiwa kwemvelo. Kuningi okungaziwa ngalezi zilwane ezithakazelisayo futhi ukusinda kwazo kusongelwa ukulahlekelwa amabhishi afulela izidleke, ipulasitiki nokunye ukungcola olwandle, nokubanjwa ngengozi amanetha okudoba nezintambo ezinde. Sisize ku I-Ocean Foundation ukusekela labo abazinikele ocwaningweni lofudu lwasolwandle kanye nemizamo yokongiwa kwemvelo ngeSikhwama sethu Sofudu Lwasolwandle.

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