I-Tuna - uhlobo lwezinhlanzi ezithandanayo, ezidla inyama, ama-mackerel. Udlale indima yesisulu esifiselekayo ngisho nangezikhathi zangaphambi komlando: imidwebo yasendulo, lapho kucatshangelwa khona izinhlaka ze-tuna, yatholakala emihumeni yaseSicily.
Isikhathi eside, njengomthombo wokudla, i-tuna yayiseceleni. Ngokufika kwemfashini yokudla kwezinhlanzi zaseJapan, i-tuna isiyadingeka kuwo wonke amazwekazi. Ukukhiqizwa kweTuna kukhule kaninginingi futhi sekuyimboni enamandla.
Incazelo nezici
I-tuna ithethelela ukuthi ungowomndeni wama-mackerel. Ukubukeka kwazo kufana nokubukeka okujwayelekile kwe-mackerel. Uhlaka olujwayelekile lomzimba nobukhulu balo lukhombisa izimfanelo ezisezingeni eliphezulu zenhlanzi. Izazi zezinto eziphilayo zithi ama-tunas akwazi ukuhamba ngaphansi kwamanzi ngejubane lama-75 km ngehora noma ama-knot angama-40.5. Kepha lokhu akuwona umkhawulo. Ekuphishekeleni inyamazane, i-bluefin tuna ingasheshisa iye kumakhilomitha angama-90 ngehora.
Ukuma kwesifuba kufana nesihlokwana esisikiwe, esikhonjwe kuzo zombili izinhlangothi. Ingxenye yesiphambano iyi-oval ejwayelekile. Engxenyeni engenhla, amaphiko amabili ayalandelana. Owokuqala mude ngemisebe eyehla ngosayizi. Owesibili mfushane, uphakeme, ugobile njengamasikela. Zombili amaphiko anemisebe elukhuni.
Umhambisi oyinhloko we-tuna umsila we-fin. Iyindilinga, inamabhande ahlukaniswe kabanzi, okukhumbuza amaphiko endiza enejubane elikhulu. Ukwakheka okungathuthukisiwe kutholakala ngemuva nasengxenyeni engezansi yomzimba. Lawa amaphiko angeziwe ngaphandle kwemisebe nolwelwesi. Kungaba nezicucu ezi-7 kuye kwezi-10.
I-tuna ngokuvamile i-pelagic ngombala. Phezulu kumnyama, izinhlangothi zilula, ingxenye yesisu icishe imhlophe. Ububanzi bombala ojwayelekile nombala wamaphiko kuncike endaweni yokuhlala kanye nohlobo lwezinhlanzi. Igama elijwayelekile lezinhlobo eziningi ze-tuna lihlotshaniswa nombala womzimba, usayizi we-fin nombala.
Ukuphefumula, ama-tunas kufanele ahambe njalo. Ukushanela komkhawulo we-caudal, ukugoba okuguqukayo kwengxenye yangaphambi kwe-caudal, kusebenza ngendlela efanele kwizembozo ze-gill: ziyavuleka. Amanzi ageleza ngomlomo ovulekile. Ugeza izigaqa. Ulwelwesi lwe-gill luthatha i-oxygen emanzini luyidedele kuma-capillaries. Ngenxa yalokho, i-tuna iyaphefumula. I-tuna emisiwe iyeka ngokuzenzakalela ukuphefumula.
Ama-tuna izinhlanzi ezinegazi elifudumele. Banekhwalithi engavamile. Ngokungafani nezinye izinhlanzi, akuzona izidalwa ezinegazi elibandayo ngokuphelele, ziyakwazi ukukhuphula izinga lokushisa lomzimba wazo. Ekujuleni kwe-1 km, ulwandle lufudumala kuze kufike ku-5 ° С. Imisipha, izitho zangaphakathi ze-bluefin tuna endaweni enjalo zihlala zifudumele - ngaphezulu kuka-20 ° C.
Umzimba wezidalwa ezinegazi elifudumele noma i-homeothermic uyakwazi ukugcina ukushisa kwemisipha nazo zonke izitho cishe kungaguquguquki, noma ngabe kushisa kangakanani emhlabeni wangaphandle. Lezi zilwane zihlanganisa zonke izilwane ezincelisayo nezinyoni.
Ama-Pisces izidalwa ezinegazi elibandayo. Igazi labo liya kuma-capillaries, adlula phakathi kwezigilo futhi abahlanganyeli ngqo ekushintshaneni kwegesi, ukuphefumula kwe-gill. Igazi likhipha isikhutha esingadingekile futhi ligcwele umoya-mpilo odingekayo ngezindonga zama-capillaries. Kuleli qophelo, igazi selipholile ekushiseni kwamanzi.
Lokho wukuthi, izinhlanzi azigcini ukushisa okwenziwa umsebenzi wemisipha. Ukuthuthuka kwama-tunas kulungise ukulahleka kokushisa kwemfucuza. Uhlelo lokunikezwa kwegazi lwalezi zinhlanzi lunezici ezithile. Okokuqala, i-tuna inemikhumbi eminingi emincane. Okwesibili, imithambo emincane nemithambo yegazi yakha inethiwekhi ehlangene, ngokwezwi nezwi. Bakha into efana ne-heat exchanger.
Igazi le-venous, elifudunyezwa yimisipha esebenzayo, liyakwazi ukunikeza ukufudumala kwalo ukupholisa igazi eligijima emithanjeni. Lokhu, nakho, kunikeza umzimba wezinhlanzi umoya-mpilo nokushisa, okuqala ukusebenza ngamandla amakhulu. Izinga elijwayelekile lomzimba liyakhuphuka. Lokhu kwenza i-tuna ibhukude ngokuphelele futhi iyisilwane esinenhlanhla kunazo zonke.
Umvunduli wendlela yokugcina izinga lokushisa lomzimba (imisipha) ku-tuna, umcwaningi waseJapan uKishinuye uhlongoze ukudala ithimba elihlukile lalezi zinhlanzi. Sebexoxile futhi baphikisana, izazi zebhayoloji azange ziqale ukubhubhisa uhlelo olusungulwe futhi zashiya i-tuna emndenini we-mackerel.
Ukushintshaniswa okushisayo okusebenzayo phakathi kwegazi elinemithambo yegazi kwenziwa ngenxa yokuhlangana kwama-capillaries. Lokhu kube nomphumela ohlangothini. Ingeze izinto eziningi eziwusizo enyameni yenhlanzi futhi yenze umbala wenyama ye-tuna wabomvu tebhu.
Izinhlobo
Izinhlobo ze-tuna, ukuhleleka kwazo, imibuzo yokwenza uhlelo lwenze ukuthi kube nokungezwani phakathi kososayensi. Kuze kube sekuqaleni kwaleli khulu leminyaka, ama-tunas ajwayelekile nawasePacific ayefakwa ohlwini lwama-subspecies enhlanzi efanayo. Kwakunezinhlobo eziyi-7 kuphela kuhlobo lo Ngemuva kokuphikisana okuningi, ama-subspecies aqanjwa abelwa isikhundla sohlobo oluzimele. Uhlobo lwe-tuna lwaqala ukuba nezinhlobo ezi-8.
- I-Thunnus thynnus iyinhlobo yokuqokwa. Ine-epithet "ejwayelekile". Imvamisa ibizwa nge-bluefin tuna. Izinhlobonhlobo ezidume kakhulu. Lapho kukhonjiswa tuna esithombeni noma bakhuluma ngetuna ngokujwayelekile basho lolu hlobo oluthile.
IMisa ingadlula u-650 kg, eqondile osayizi be-tuna esondela kumaki we-4.6 m. Uma abadobi bekwazi ukubamba isampuli izikhathi eziphindwe kathathu, lokhu kubhekwa njengempumelelo enkulu.
Izilwandle zaseTropical yindawo yokuhlala eyinhloko ye-tuna ye- bluefin. E-Atlantic kusuka eMedithera kuya eGulf of Mexico, amafolishi e-tuna nabadobi bazama ukubamba le nhlanzi.
- I-Thunnus alalunga - etholakala kakhulu ngaphansi kwegama elithi albacore noma i-longfin tuna. I-Pacific, i-Indian ne-Atlantic, izilwandle zasendaweni eshisayo zihlala ekhaya le-longfin tuna. Izikole zama-albacores zenza ukufuduka kwe-transoceanic zifuna ukudla okungcono nokuzala kabusha.
Isisindo esiphezulu se-albacore cishe singama-60 kg, ubude bomzimba abudluli kumamitha ayi-1,4. ILongfin tuna ibanjwa ngentshiseko olwandle i-Atlantic nePacific. Le nhlanzi ilwela ubukhulu phakathi kwe-tuna ngokunambitheka.
- I-Thunnus maccoyii - ngenxa yokunamathela kwayo olwandle oluseningizimu, inegama elibizwa ngokuthi i-blue southern noma i-blue finned eningizimu, noma i-tuna yase-Australia. Ngokwesisindo nobukhulu, ithatha isikhundla esimaphakathi phakathi kwe-tuna. Ikhula ize ifike ku-2,5 m bese izuza isisindo esifinyelela ku-260 kg.
Lokhu tuna kutholakala olwandle olufudumele lwengxenye eseningizimu yeWorld Ocean. Izikole zalezi zinhlanzi zondla ngasogwini oluseningizimu ye-Afrika naseNew Zealand. Isendlalelo esikhulu samanzi lapho ama-tunas aseningizimu aphishekela inyamazane ungqimba lwaphezulu. Kepha futhi abesabi ukuntywila ngamamayela. Amacala ama-tunas ase-Australia ahlala ekujuleni kwe-2,774 m aqoshwe.
- I-Thunnus obesus - kuma-specimens amakhulu, ubukhulu beso bungosososo omuhle. IBigeye tuna yigama elivame kakhulu kule nhlanzi. Inhlanzi enobude obungu-2.5 m nesisindo esingaphezu kwama-200 kg ngamapharamitha amahle ngisho nasetuna.
Ayingeni eMedithera. Kwezinye izindawo ezivulekile zasePacific, e-Atlantic naseNdiya, iyatholakala. Izindlu zokuhlala ngaphezulu, kuze kufike ekujuleni okungama-300m. Inhlanzi ayivamile kakhulu, iyinto yokudoba i-tuna.
- I-Thunnus orientalis - Umbala nendawo okuhlala kuyo yanikeza le nhlanzi igama elithi Pacific bluefin tuna. Akuyona le tuna kuphela ebhekise kumbala womzimba ohlaza okwesibhakabhaka, ngakho-ke ukudideka kungenzeka.
- AmaThunnus albacares - ngenxa yombala wamaphiko, athola igama elithi yellowfin tuna. Izindawo ezishisayo nezindawo eziphakeme zasolwandle ziyindawo okuhlala kuyo le tuna. I-tuna ye-yellowfin ayikubekezeleli ukubanda kwamanzi kune-18 ° C. Ifuduka ngokunganaki, ivame ukuma mpo: kusuka ekujuleni kwamakhaza kuya endaweni efudumele.
- I-Thunnus atlanticus - i-black back ne-Atlantic yanikeza lolu hlobo igama i-Atlantic, i-darkfin noma i-blackfin tuna. Lezi zinhlobo zigqama kwezinye izinhlobo ngesilinganiso sazo sokuvuthwa. Eminyakeni emi-2 ubudala, angazala inzalo, eneminyaka engu-5 ubudala i-tuna emnyama ibhekwa njengendala.
- I-Thunnus tonggol - I-tuna enomsila omude ibizwa ngenxa ye-foretail elicwengekile. Le tuna encane. Ubukhulu obukhulu bomugqa abudluli ku-1.45 m, ubukhulu be-36 kg ngumkhawulo. Amanzi ashubisa phansi asolwandle e-Indian nasePacific Ocean ayindawo yokuhlala i-tuna enomsila omude. Le nhlanzi ikhula kancane kunenye i-tuna.
Kufanele kushiwo ukuthi umndeni wama-mackerel unawo inhlanzi, efana ne-tuna - Lona yi-Atlantic bonita noma i-bonita. Umndeni uqukethe nezinhlobo ezihlobene, ezifanayo hhayi kuphela emigqeni yomzimba, kodwa nasegama. Ezinye zazo, njenge-tuna enemigqa, zibaluleke kakhulu kwezohwebo.
Indlela yokuphila nendawo yokuhlala
Ama-tuna izinhlanzi ezifundayo. Bachitha isikhathi sabo esiningi endaweni ye-pelagic. Okusho ukuthi, ababheki ukudla ezansi futhi abakuqoqi ebusweni bamanzi. Ohlwini lwamanzi, bavame ukuhamba ngendiza ebheke phezulu. Ukuqondiswa kokuhamba kunqunywa ukushisa kwamanzi. Izinhlanzi ze-tuna zivame ukungena ezingxenyeni zamanzi ezifudumele kuze kufike ku-18-25 ° C.
Ngenkathi izingela ngemihlambi, i-tuna ithuthukise indlela elula nephumelelayo. Bazungeza isikole sezinhlanzi ezincane ezinesikwele, abazokudla. Bese behlasela ngokushesha. Ijubane lokuhlaselwa nokumuncwa kwezinhlanzi liphezulu kakhulu. Ngesikhathi esifushane, i-tuna idla isikole sonke sokudla.
Ngekhulu le-19, abadobi bakuqaphela ukusebenza kwe-tuna zhora. Babona lezi zinhlanzi njengabancintisana nabo. Ngasogwini olusempumalanga neMelika, olunothile ngezinhlanzi, baqala ukudoba ithuna ukuvikela izinhlanzi. Kuze kube maphakathi nekhulu lama-20, inyama ye-tuna yayinganakwa kangako futhi yayivame ukusetshenziselwa ukukhiqizwa kokudla kwezilwane.
Ukudla okunomsoco
Izinhlobo zezinhlanzi zondla nge-zooplankton, zidle izibungu kanye nefry yezinye izinhlanzi ezitholakale zingacabangi endaweni ye-pelagic. Njengoba zikhula, izinhlanzi ze-tuna zikhetha izinhloso ezinkulu njengezisulu. I-tuna yabantu abadala ihlasela imihlambi ye-herring, i-mackerel, futhi ibhubhise yonke imiphakathi yama-squid.
Ukuzala kanye nesikhathi sokuphila
Onke ama-tunas anecebo elilula lokusinda lezinhlobo: akhiqiza amaqanda amakhulu kakhulu. Owesifazane othile omdala angazala amaqanda afinyelela ezigidini eziyishumi. Ama-tunas ase-Australia angakhiqiza amaqanda angafika ezigidini eziyi-15.
Izinhlanzi zasolwandle ze-tunaokhula sekwedlule isikhathi. Ezinye izinhlobo zithola ikhono lokukhiqiza inzalo eminyakeni eyi-10 noma ngaphezulu. Isikhathi sokuphila salezi zinhlanzi naso asisifushane, sifinyelela eminyakeni engama-35. Izazi zezinto eziphilayo zithi i-tuna ehlala isikhathi eside ingaphila kuze kube yiminyaka engama-50.
Intengo
I-tuna iyinhlanzi enempilo... Inyama yayo yaziswa kakhulu eJapan. Kuleli zwe kuza izindaba zabantu abafinyelela phezulu intengo ye-tuna endalini yezitolo. Abezindaba ngezikhathi ezithile babika ngamarekhodi entengo alandelayo. Inani le-US $ 900-1000 kg nge-tuna ngayinye alisabonakali lihle.
Ezitolo zezinhlanzi zaseRussia, amanani entengo e-tuna aphakathi nendawo. Isibonelo, isitaki se-tuna singathengwa ngama-ruble ayi-150. Ithini elingamakhulu amabili-gamu le-tuna elisethinini akunzima ukuthenga ngama-ruble angama-250 noma ngaphezulu, kuya ngohlobo lwe-tuna nezwe lokukhiqiza.
Ukudoba iTuna
Izinhlanzi ze-tuna abanjwe ngezinjongo zokuhweba. Ngaphezu kwalokho, kuyindaba yokudoba imidlalo nezindebe. Ukudoba ama-tuna ezimbonini kube nenqubekela phambili emangalisayo. Ekhulwini elidlule, imikhumbi yokudoba ithuna yahlonyiswa kabusha.
Ngama-80s, baqala ukwakha amatilosi anamandla agxile kuphela ekubambeni i-tuna. Ithuluzi eliyinhloko lale mikhumbi i-purse seine, ehlukaniswa ngokwazi ukucwila kumamitha amaningi amakhulu kanye nokukwazi ukuphakamisa umhlambi omncane we-tuna ngasikhathi sinye.
Izinhlobo ezinkulu ze-tuna zibanjwa zisebenzisa ama-longline. Le yingwegwe, ayilungiswanga ngobuhlakani. Esikhathini esingengakanani esidlule, ukubanjwa kwamahhuku kwakusetshenziswa kuphela emapulazini amancane okudoba. Manje bakha imikhumbi ekhethekile - ama-longliners.
Amathayi - izintambo eziningana eziqonde mpo (imigqa), lapho kutholakala khona izingwegwe ngezingwegwe. Iziqu zenyama yenhlanzi zisetshenziswa njengesithiyelo semvelo. Imvamisa zikhishwa ngenqwaba yezintambo ezinemibala noma ezinye izifanisi zezilwane. Indlela yesikole yokudla kwe-tuna yenza imisebenzi yabadobi ibe lula kakhulu.
Lapho kubanjwa i-tuna, kuvela inkinga enkulu - lezi zinhlanzi zivuthwa sekwedlule isikhathi. Ezinye izinhlobo zidinga ukuba ziphile iminyaka eyi-10 ngaphambi kokuba zikhiqize inzalo ye-tuna. Izivumelwano zomhlaba wonke zibeka imingcele ekubanjweni kwe-tuna encane.
Emazweni amaningi, ngomzamo wokulondoloza inani le-tuna futhi lenze imali, izingane azivunyelwe ngaphansi kommese. Ziyiswa emapulazini ezinhlanzi asogwini lapho izinhlanzi zikhuliselwa khona ukuze zibe zindala. Imizamo yemvelo neyezezimboni iyahlanganiswa ukwandisa ukukhiqizwa kwezinhlanzi.
