"King of all fish" - mutuwu udapatsidwa tuna mu 1922 ndi Ernest Hemingway, yemwe adachita chidwi ndi torpedo yonyezimira yomwe idadutsa mafunde am'mbali mwa Spain.
Kufotokozera za tuna
Akatswiri ofufuza zachipatala amazindikira kuti tuna ndi amodzi mwa anthu abwino kwambiri m'nyanja... Nsombazi, zomwe dzina lawo limachokera ku Chigiriki chakale. muzu "thynō" (kuponya), ali m'banja la Scombridae ndipo amapanga genera 5 yokhala ndi mitundu 15. Mitundu yambiri ilibe chikhodzodzo chosambira. Tuna ndiosiyana kwambiri kukula kwake (kutalika ndi kulemera kwake) - nsomba ya mackerel imakula mpaka theka la mita ndipo imalemera makilogalamu 1.8, pomwe tuna ya bluefin imapindula mpaka 300-500 kg yokhala ndi 2 mpaka 4.6 m.
Mtundu wa tuna yaying'ono umaphatikizapo:
- skipjack, aka milozo tuna;
- kum'mwera nsomba;
- nsomba zamadontho;
- nsomba ya mackerel;
- Nsomba ya Atlantic.
Mtundu wa tuna weniweni umaimiridwa ndi mitundu yochititsa chidwi kwambiri, monga:
- longfin nsomba;
- tuna wamaso akulu;
- chikopa tuna;
- wamba (buluu / buluu wonyezimira).
Otsatirawa amasangalatsa asodzi ndi zitsanzo zabwino kwambiri: amadziwika, mwachitsanzo, kuti mu 1979, pafupi ndi Canada, nsomba ya bluefin tunagwidwa, yotambasula pafupifupi 680 kg.
Maonekedwe
Tuna ndi cholengedwa champhamvu modabwitsa chomwe chilengedwe chimapatsa mawonekedwe abwino ndi kusintha kwachilengedwe... Tanasi zonse zimakhala ndi matupi otalikirana, opindika ngati tinthu tomwe timathandiza kuti tikwaniritse kuthamanga komanso kuthana ndi mtunda wautali. Kuphatikiza apo, mawonekedwe abwino am'mbali yam'mbuyo, yakufa ngati chikwakwa, akuyenera kuthokoza chifukwa chothamanga komanso kusambira kwakanthawi.
Ubwino wina wamtundu wa Thunnus ndi monga:
- chiphalaphala cholimba modabwitsa;
- kuchuluka kwa kusinthanitsa kwa gasi;
- zodabwitsa biochemistry / physiology yamtima ndi mitsempha yamagazi;
- kuchuluka kwa hemoglobin;
- mitsempha yambiri yomwe imasefa madzi kotero kuti tuna imalandira 50% ya mpweya wake (mu nsomba zina - 25-33%);
- Njira yabwino kwambiri yopezera kutentha m'maso, muubongo, minofu ndi pamimba.
Chifukwa chakumapeto kwake, thupi la tuna limakhala lotentha nthawi zonse (pofika 9-14 ° C) wachilengedwe, pomwe kutentha kwake kwa nsomba zambiri kumafanana ndi kutentha kwamadzi. Malongosoledwe ake ndiosavuta - amataya kutentha pantchito yamphamvu, chifukwa magazi amapitilira m'mitsempha yamagetsi: apa sikuti imangopindulitsa ndi mpweya, komanso imazizira mpaka kutentha kwamadzi.
Zofunika! Chowonjezera chowonjezera chowonjezera cha kutentha (countercurrent) chomwe chili pakati pamitsempha ndi ziwalo zina zonse chimatha kuwonjezera kutentha kwa thupi. Tona zonse zimakhala ndi kutentha kwachilengedwe.
Chifukwa cha iye, bluefin tuna amasunga kutentha kwa thupi mozungulira + 27 + 28 ° С, ngakhale pamtunda wakilomita imodzi, pomwe madzi satenthetsa pamwamba +5 ° С. Kufunda kwamagazi ndi komwe kumapangitsa kuti minofu ikhale yolimba yomwe imapatsa tuna liwiro labwino kwambiri. Wosakanikirana ndi kutentha kwa tuna ndi netiweki yazombo zazing'onozing'ono zomwe zimapereka magazi kumtundu wotsatira, pomwe gawo lalikulu limaperekedwa ku minofu yofiira (ulusi wa minofu yapadera yapafupi ndi msana).
Mitsempha yomwe imathirira minofu yofiyira yofiira ndi magazi imapindidwa kukhala njira yovuta kwambiri yamitsempha yolumikizana ndi mitsempha, kudzera momwe magazi amayendera mbali zosiyana. Magazi oyipa a tuna (otenthedwa ndi ntchito ya minofu ndikutulutsidwa ndi mtima ventricle) amasamutsira kutentha kwake osati madzi, koma magazi owerengeka (owerengera) opsinjika ndi mitsempha. Ndipo minofu ya nsombayo imatsukidwa ndikutuluka kwamagazi kofunda kale.
Woyamba kuzindikira ndi kufotokoza za mawonekedwe amtundu wa Thunnus anali wofufuza waku Japan K. Kissinuye. Adafunsanso kuti ayike ma tunas onse pagulu lodziyimira pawokha, koma mwatsoka sanalandire chithandizo cha anzawo.
Khalidwe ndi moyo
Tuna amatengedwa ngati nyama zomwe zimakonda kucheza - zimasonkhana m'magulu akulu ndikusaka m'magulu. Pofunafuna chakudya, nsomba za pelagiczi ndizokonzekera kuponyera patali kwambiri, makamaka chifukwa amatha kudalira maluso awo okhala.
Ndizosangalatsa! Ma buluu wamba (wamba) amakhala ndi gawo lawo mkango pazolemba zothamanga za World Ocean. Mtunda waufupi bluefin tuna imatha kupitilira pafupifupi 90 km / h.
Kupita kukasaka, ma tunas amafika pamzere wopindika (wofanana ndi chingwe cha uta wotambasulidwa) ndikuyamba kuyendetsa nyama yawo mwachangu kwambiri. Mwa njira, kusambira kwamuyaya kumachokera mu biology ya mtundu wa Thunnus. Kuyimitsa kumawopseza ndi imfa, chifukwa njira yopumira imayambitsidwa ndi kupindika kwa thupi, kuchokera kumapeto kwa caudal. Kupita patsogolo kumathandizanso kuti madzi azituluka mosadumphadutsa pakamwa ndikulowera m'mitsempha.
Utali wamoyo
Kutalika kwa moyo wa nyama zodabwitsa za m'nyanjazi kumadalira mitundu - makamaka oimira ake, amatalikitsa moyo... Mndandanda wazaka zana limodzi umaphatikizapo tuna wamba (zaka 35-50), tuna waku Australia (20-40) ndi Pacific bluefin tuna (zaka 15-26). Yellowfin tuna (5-9) ndi mackerel tuna (zaka 5) ndizocheperako padziko lapansi.
Malo okhala, malo okhala
Tuna adadzipatula okha kuchokera ku mackerel ena opitilira 40 miliyoni zaka zapitazo, akukhazikika mu Nyanja Yadziko Lonse (kupatula nyanja zam'madzi).
Ndizosangalatsa! Kale mu Stone Age, zithunzi mwatsatanetsatane za nsomba zidapezeka m'mapanga a Sicily, ndipo mu Bronze ndi Iron Ages, asodzi aku Mediterranean (Agiriki, Afoinike, Aroma, Aturuki ndi a Moroccans) adawerengera masiku asanafike nsomba.
Osati kale kwambiri, tuna wamba wamba anali wokulirapo kwambiri ndipo adakuta Nyanja yonse ya Atlantic, kuyambira ku Canary Islands mpaka ku North Sea, komanso ku Norway (komwe adasambira mchilimwe). Bluefin tuna anali chizolowezi chokhala mu Nyanja ya Mediterranean, nthawi zina amalowa ku Black Sea. Adakumananso pagombe la Atlantic ku America, komanso m'madzi a East Africa, Australia, Chile, New Zealand ndi Peru. Pakadali pano, mtundu wa tuna wa bluefin wachepa kwambiri. Malo okhala nsomba zazing'ono amagawidwa motere:
- Southern tuna - madzi otentha a kum'mwera kwa dziko lapansi (New Zealand, South Africa, Tasmania ndi Uruguay);
- nsomba ya mackerel - madera a m'mphepete mwa nyanja ofunda;
- nsomba zamadontho - Indian Ocean ndi Western Pacific;
- Atlantic tuna - Africa, America ndi Mediterranean;
- skipjack (mitsinje ya tuna) - madera otentha ndi otentha a Pacific Ocean.
Zakudya, zakudya
Tuna, makamaka yayikulu kwambiri (yamtambo), imadya pafupifupi chilichonse chomwe chili pakulimba kwa nyanja - kusambira kapena kugona pansi.
Chakudya choyenera cha tuna ndi awa:
- nsomba zophunzitsira, kuphatikiza hering'i, mackerel, hake ndi pollock;
- fulonda;
- nyamayi ndi octopus;
- sardine ndi anchovy;
- mitundu yaing'ono ya shark;
- nkhanu, kuphatikizapo nkhanu;
- ziphuphu;
- milomo yongokhala.
Asodzi ndi akatswiri azachthyologists amatha kuzindikira mosavuta malo omwe tuna stranglehold herring - mamba awo owala amapindika kukhala ming'alu yomwe pang'onopang'ono imatha msanga ndipo imasungunuka pang'onopang'ono. Ndipo mamba okhaokha omwe analibe nthawi yakumira pansi amakumbutsa kuti tuna adya kumene kuno.
Nsomba zobereketsa
M'mbuyomu, akatswiri a zachthyologists anali otsimikiza kuti kuzama kwa North Atlantic kunkakhala magulu awiri a tuna wamba - m'modzi amakhala ku Western Atlantic ndipo amabwera ku Gulf of Mexico, ndipo wachiwiri amakhala ku East Atlantic, kusiya kukabereka Nyanja ya Mediterranean.
Zofunika! Zinachokera ku lingaliro ili pomwe International Commission for Conservation of Atlantic Tuna idapitilira, ndikuyika magawo azomwe adzagwire. Kusodza kunali kochepa ku Western Atlantic, koma kumaloledwa (kwakukulu) Kum'mawa.
Popita nthawi, lingaliro la ziweto ziwiri za Atlantic lidazindikirika kuti silolondola, lomwe makamaka limathandizidwa ndikulemba nsomba (komwe kudayamba mkatikati mwa zaka zapitazi) ndikugwiritsa ntchito njira zamagulu am'maselo. Kwa zaka zopitilira 60, zinali zotheka kudziwa kuti tuna imaberekadi m'magulu awiri (Gulf of Mexico ndi Nyanja ya Mediterranean), koma nsomba iliyonse imasamukira kumalo osiyanasiyana kupita kwina, zomwe zikutanthauza kuti anthu onse ndi amodzi.
Chigawo chilichonse chimakhala ndi nyengo yake yoswana. Ku Gulf of Mexico, tuna timayamba kubala kuyambira pakati pa Epulo mpaka Juni, pomwe madzi amatentha mpaka + 22.6 + 27.5 ° C. Kwa tuna ambiri, kubala koyamba kumachitika osapitilira zaka 12, ngakhale kutha msinkhu kumachitika zaka 8-10, nsomba zikakula mpaka mamita 2. Mu Nyanja ya Mediterranean, kubereka kumachitika kale kwambiri - atakwanitsa zaka zitatu. Kutulutsa kumachitika mchilimwe, mu Juni - Julayi.
Tuna ndi yachonde kwambiri.... Anthu akuluakulu amabereka pafupifupi mazira 10 miliyoni (1.0-1.1 masentimita kukula). Pakapita kanthawi, mphutsi ya 1-1.5 cm imaswa kuchokera dzira lililonse lokhala ndi mafuta. Mphutsi zonse zimakhamukira m'magulu apamadzi.
Adani achilengedwe
Tuna ili ndi adani achilengedwe ochepa: chifukwa cha kuthamanga kwake, imathawa molondola omwe amawatsata. Komabe, tuna nthawi zina amalimbana ndi mitundu ina ya nsombazi, komanso amatengeka ndi nsomba zam'madzi.
Mtengo wamalonda
Anthu akhala akudziwa nsomba za tuna kwanthawi yayitali - mwachitsanzo, nzika zaku Japan zakhala zikukolola buluu wa tuna kwa zaka zopitilira 5 zikwi. Barbara Block, pulofesa ku yunivesite ya Stanford, ali wotsimikiza kuti mtundu wa Thunnus udathandizira kumanga chitukuko chakumadzulo. Barbara akutsimikizira kumaliza kwake ndi mfundo zodziwika bwino: tuna adagwetsedwa pamtengo wachi Greek ndi Celtic, ndipo asodzi a Bosphorus adagwiritsa ntchito ma 30 (!) Mayina osiyanasiyana kutchula tuna.
“Kunyanja ya Mediterranean, maukonde ankakhazikitsidwira ma tunas akuluakulu omwe ankadutsa m'mphepete mwa nyanja ya Gibraltar chaka chilichonse, ndipo msodzi aliyense m'mbali mwa nyanja ankadziwa nthawi yomwe asodzi ayambira. Migodi inali yopindulitsa, popeza katundu wamoyo adagulitsa mwachangu, "asayansi akukumbukira.
Kenako malingaliro aku nsombazi adasintha: adayamba kunena monyoza kuti "horse mackerel" ndikuzichotsa pamasewera, kenako nkuzisiya kuti zikapange umuna kapena kuziponyera amphaka. Komabe, mpaka kumayambiriro kwa zaka zana zapitazo pafupi ndi New Jersey ndi Nova Scotia, mtundu wa tuna (monga mpikisano wamkulu pakusodza) udagwidwa ndi makampani angapo osodza. Koma chingwe cholimba chakuda chidayamba kwa tuna zaka 50-60 zapitazo, pomwe sushi / sashimi yopangidwa kuchokera ku nyama yake idalowa m'mafashoni.
Ndizosangalatsa! Tuna ya Bluefin ikufunidwa kwambiri ku Land of the Rising Sun, pomwe 1 kg ya nsomba imawononga $ 900. Ku States komwe, nsomba ya bluefin imangodyetsedwa m'malesitilanti apamwamba, pogwiritsa ntchito yellowfin kapena bigeye tuna m'malo opepuka.
Kusaka tuna ya bluefin kumawerengedwa kuti ndi ulemu wapadera kwa magulu aliwonse osodza, koma sikuti aliyense amatenga tuna wonenepa kwambiri komanso wofunika kwambiri. Ogula nsomba za ma gourmets aku Japan asintha kale tuna kupita kumpoto kwa Atlantic, chifukwa ndiosangalatsa kuposa anzawo aku Japan.
Chiwerengero cha anthu komanso mtundu wa mitunduyi
Pakukula kwa mitundu ya tuna, m'pamenenso zimawopsa kwambiri posamalira zachilengedwe.... Pakadali pano, nsomba yabuluu (wamba) amadziwika kuti ndi nyama yomwe ili pangozi, ndipo tuna waku Australia watsala pang'ono kutha. Mitundu iwiri idatchedwa yotetezeka - bigeye ndi Pacific bluefin tuna. Longfin ndi Yellowfin tuna amadziwika kuti ali pafupi ndi omwe ali pachiwopsezo, pomwe mitundu ina ili ndi nkhawa yayikulu (kuphatikiza Atlantic tuna).
Pofuna kusunga ndikubwezeretsa kuchuluka kwa anthu, tsopano ndizosatheka (malinga ndi mgwirizano wapadziko lonse lapansi) kugwira nsomba zomwe sizinakule kufika pa 2 mita. Kusunga uku kumagwiritsidwa ntchito ndi mayiko onse apanyanja kupatula Israeli: asodzi azungulira tuna wachinyamata ndi maukonde, ndikuwakokera kumakola ena apadera kuti amanenepa. Mwanjira imeneyi, nsomba ya mita imodzi ndi mita imodzi ndi theka imagwidwa - mochulukira kangapo kuposa nsomba zazikulu.
Zofunika! Poganizira kuti "minda ya nsomba" sikubwezeretsanso, koma kuchepetsa kuchuluka kwa anthu, WWF yapempha kuti nsomba za tuna ziziyenda mu Nyanja ya Mediterranean. Kuyitana kwa 2006 kudakanidwa ndi malo olandirira asodzi.
Lingaliro linanso (lomwe lidakhazikitsidwa mu 2009 ndi a Principality of Monaco) silinaphatikizenso mtundu wa tuna wa bluefin mu Convention on International Trade in Endangered Flora / Fauna (Zowonjezera I). Izi zitha kuletsa malonda apadziko lonse a tuna, nthumwi zodandaula za CITES zidaletsa njira yomwe inali yovutitsa mayiko awo.
