Tuna - mtundu wa nsomba zochuluka, zodyera, nsomba za mackerel. Adasewera ngati nyama yosilira ngakhale m'mbuyomu: zojambula zakale, momwe malingaliro a tuna amaganiziridwa, adapezeka m'mapanga a Sicily.
Kwa nthawi yayitali, monga chakudya, tuna anali pambali. Pakubwera mafashoni azakudya zaku Japan zansomba, nsomba za tuna zakhala zikufunika kumayiko onse. Kupanga nsomba kwawonjezeka kambirimbiri ndipo kwakhala bizinesi yamphamvu kwambiri.
Kufotokozera ndi mawonekedwe
Tuna imatsimikizira kukhala am'banja la mackerel. Maonekedwe awo amafanana ndi mawonekedwe abulu a mackerel. Kutalika kwa thupi ndi mawonekedwe ake kumawonetsa kuthamanga kwa nsombazo. Akatswiri a zamoyo amati tunas amatha kuyenda pansi pa madzi pa liwiro la 75 km paola kapena mafundo 40.5. Koma awa si malire. Pofunafuna nyama, buluu wa buluu amatha kuthamangira ku 90 km paola.
Maonekedwe a torso amafanana ndi ellse kutalika kwake, kolozera kumapeto onse awiri. Gawo la mtanda ndilowulungika nthawi zonse. Pamwamba pake, zipsepse ziwiri zimatsatizana. Yoyamba ndiyitali motalika ndi cheza chokulirapo. Lachiwiri ndi lalifupi, lokwera, lopindika ngati chikwakwa. Zipsepse zonsezo zimakhala ndi cheza cholimba.
Choyendetsa chachikulu cha tuna ndi mchira kumapeto. Ndiwofanana, wokhala ndi masamba otalikirana, okumbutsa mapiko a ndege yothamanga kwambiri. Mapangidwe osatukuka amapezeka kumbuyo ndi kumapeto kwa thupi. Awa ndi zipsepse zowonjezera popanda kuwala ndi nembanemba. Pakhoza kukhala zidutswa 7 mpaka 10.
Mtundu wa tuna nthawi zambiri umakhala pelagic. Pamwamba pamakhala mdima, mbali zake ndizopepuka, gawo lam'mimba limakhala loyera. Mitundu yonse ya zipsepsezo zimadalira malo okhala ndi mtundu wa nsomba. Dzinalo lodziwika bwino pamitundu yambiri ya tuna limalumikizidwa ndi mtundu wa thupi, kukula kwake ndi utoto.
Kupuma, ma tunas amayenera kusuntha nthawi zonse. Kusesa kwa chimbudzi chakumapeto, kukhotakhota kwa gawo lotsogola, kumachita chimakwirira pazitseko: amatsegula. Madzi amayenda pakamwa potseguka. Amatsuka minyewa. Mimbulu ya gill imatenga mpweya m'madzi ndikuyipititsa ku ma capillaries. Zotsatira zake, tuna amapuma. Kuyimitsidwa kwa tuna kumasiya kupuma.
Tuna ndi nsomba zamagazi ofunda. Ali ndi khalidwe losazolowereka. Mosiyana ndi nsomba zina, sizilombo zopanda magazi, amadziwa momwe angakulitsire kutentha kwa thupi lawo. Pakuya kwa 1 km, nyanja imangotentha mpaka 5 ° С. Minofu, ziwalo zamkati za tuna ya bluefin m'malo otere zimakhala zotentha - pamwamba pa 20 ° C.
Thupi la zolengedwa zamagazi ofunda kapena zakuthambo zimatha kutentha kwa minofu ndi ziwalo zonse pafupifupi mosasinthasintha, mosasamala kanthu kutentha kwa dziko lakunja. Nyama izi zimaphatikizapo zinyama zonse ndi mbalame.
Pisces ndi zolengedwa zamagazi ozizira. Magazi awo amapita kuma capillaries, omwe amadutsa m'mitsempha ndipo amatenga nawo gawo posinthana ndi mpweya, kupuma kwa gill. Mwazi umatulutsa carbon dioxide wosafunikira ndipo umadzaza ndi mpweya wofunikira kudzera m'makoma a capillaries. Pakadali pano, magazi amakhala atakhazikika mpaka kutentha kwamadzi.
Ndiye kuti, nsomba sizisunga kutentha komwe kumapangidwa ndimphamvu zamagulu. Kukula kwa ma tunas kwakonzanso kuwonongeka kwa kutentha. Njira yamagazi ya nsombazi ili ndi zina zapadera. Choyambirira, tuna tili ndi ziwiya zazing'ono zambiri. Kachiwiri, mitsempha yaying'ono ndi mitsempha imapanga netiweki yolumikizana, yoyandikana kwenikweni. Amapanga china chake ngati chosinthana ndi kutentha.
Mwazi wamagazi, wotenthedwa ndi minofu yogwira ntchito, amatha kupereka kutentha kwake kuti kuziziritsa magazi oyenda m'mitsempha. Izi zimapatsanso thupi la nsomba mpweya wabwino komanso kutentha, komwe kumayamba kugwira ntchito mwamphamvu kwambiri. Mlingo waukulu wa thupi umakwera. Izi zimapangitsa kuti tuna azisambira komanso kudya nyama zabwino kwambiri.
Wopezera njira yosungira kutentha kwa thupi (minofu) mu tuna, wofufuza waku Japan Kishinuye adalimbikitsa kupanga gulu lina la nsombazi. Atakambirana ndikukangana, akatswiri asayansi sanayambe kuwononga dongosolo lomwe lidakhazikitsidwa ndikusiya tuna m'banja la mackerel.
Kusinthasintha kotentha pakati pamitsempha yamagazi ndi magazi kumachitika chifukwa chothana kwa ma capillaries. Izi zinali ndi zoyipa zina. Idawonjezera zinthu zambiri zothandiza ku nyama ya nsomba ndikupangitsa mtundu wa tuna kukhala wofiirira.
Mitundu
Mitundu ya tuna, kuyitanitsa kwawo, mafunso okhudzana ndi makonzedwe adayambitsa kusamvana pakati pa asayansi. Mpaka kumayambiriro kwa zaka za zana lino, ma tunas wamba ndi Pacific adatchulidwa ngati subspecies za nsomba zomwezo. M'ndendemo munali mitundu 7. Koma atakangana kwambiri, ma subspecies omwe adatchulidwayo adapatsidwa gawo lodziyimira palokha. Mtundu wa tuna udayamba kukhala ndi mitundu 8.
- Thunnus thynnus ndi mtundu wosankhidwa. Ali ndi epithet "wamba". Amakonda kutchedwa tuna ya bluefin. Mitundu yotchuka kwambiri. Mukamawonetsedwa tuna pachithunzichi kapena amalankhula za tuna ambiri amatanthauza mtunduwu.
Misa akhoza kupitirira 650 makilogalamu, liniya kukula kwa tuna kuyandikira chizindikiro cha 4.6 m. Ngati asodzi amatha kugwira choyerekeza kangapo katatu, izi zimawonekeranso kukhala zopambana.
Nyanja zam'malo otentha ndi malo okhalamo nsomba za bluefin. Ku Atlantic kuchokera ku Mediterranean mpaka ku Gulf of Mexico, akudya nsomba ndi asodzi amayesa kugwira nsomba imeneyi.
- Thunnus alalunga - omwe amapezeka kwambiri pansi pa dzina loti albacore kapena longfin tuna. Pacific, Indian ndi Atlantic, nyanja zam'madera otentha zimakhala ndi nsomba za longfin. Sukulu za albacores zimasamukira kunyanja kukafuna chakudya chabwino ndi kubereka.
Kulemera kwakukulu kwa albacore kuli pafupifupi makilogalamu 60, kutalika kwa thupi sikupitilira mita 1.4. Longfin tuna imagwira mwamphamvu kunyanja ya Atlantic ndi Pacific. Nsomba iyi ikumenyera ufulu pakati pa tuna mwa kukoma.
- Thunnus maccoyii - chifukwa cholumikizidwa kunyanja zakumwera, ili ndi dzina loti buluu lakumwera kapena lopangidwa ndi buluu kum'mwera, kapena tuna waku Australia. Ponena za kulemera kwake ndi kukula kwake, imakhala pakati pa tuna. Amakula mpaka 2.5 m ndikupeza kulemera mpaka 260 kg.
Izi tuna amapezeka m'nyanja zotentha zakum'mwera kwa World Ocean. Sukulu za nsombazi zimadya m'mphepete mwa nyanja kumwera kwa Africa ndi New Zealand. Mzere waukulu wamadzi pomwe ma tunas akumwera amayendetsa nyama ndi wosanjikiza pamwamba. Koma samawopanso kutuluka ma mile. Milandu yama tunas aku Australia omwe amakhala mozama mamita 2,774 yajambulidwa.
- Thunnus obesus - m'mitundu yayikulu, m'mimba mwake ndiye kukula kwa msuzi wabwino. Nsomba ya Bigeye ndi dzina lodziwika kwambiri la nsombayi. Nsomba zotalika 2.5 m ndi zolemera makilogalamu opitilira 200 ndi magawo abwino ngakhale a tuna.
Sakulowa ku Mediterranean. M'madera ena omasuka a Pacific, Atlantic ndi Indian, amapezeka. Amakhala pafupi ndi padziko, mpaka kuzama kwa 300m. Nsombazo sizachilendo, ndizophera nsomba.
- Thunnus orientalis - Mtundu ndi malo okhala anapatsa nsomba iyi dzina Pacific Pacific bluefin tuna. Sikuti tuna iyi imangotchula mtundu wabuluu wabuluu, ndiye kuti pangakhale chisokonezo.
- Thunnus albacares - chifukwa cha utoto wa zipsepsezo, idatchedwa yellowfin tuna. Malo otentha ndi madera ozizira a m'nyanja ndizomwe zimakhala ndi tuna iyi. Yellowfin tuna siyimalekerera madzi ozizira kuposa 18 ° C. Imasuntha mopanda tanthauzo, nthawi zambiri mozungulira: kuchokera kuzizira mpaka kumalo otentha.
- Thunnus atlanticus - wakuda kumbuyo ndi Atlantic adapatsa mtundu uwu dzina la Atlantic, darkfin kapena blackfin tuna. Mitunduyi imasiyanitsa ndi enawo ndi kukula kwake. Ali ndi zaka 2, amatha kubereka ana, ali ndi zaka 5, tuna wakuda amadziwika kuti ndi wokalamba.
- Thunnus tonggol - tuna wautali wautali amatchedwa chifukwa chamiyala yoyera. Iyi ndi tuna yaying'ono kwambiri. Kukula kwake kwazitali sikudutsa 1.45 m, kulemera kwa 36 kg ndiye malire. Madzi otentha a m'nyanja ya Indian ndi Pacific ndi malo okhala ndi nsomba zazitali. Nsombazi zimayamba pang'onopang'ono kuposa nsomba zina.
Ndikoyenera kutchula kuti banja la mackerel liri nalo nsomba, ngati tuna - Iyi ndi bonita ya Atlantic kapena bonita. Banja lilinso ndi mitundu yofananira, yofanana osati mizere yamthupi yokha, komanso dzina. Zina mwazo, monga nsomba zamizere, ndizofunika kwambiri pakampani.
Moyo ndi malo okhala
Tuna ndi nsomba zopita kusukulu. Nthawi yayikulu imagwiritsidwa ntchito mdera la pelagic. Ndiye kuti, samafunafuna chakudya pansi ndipo samachisonkhanitsa pamwamba pamadzi. M'mbali yamadzi, nthawi zambiri amayenda mozungulira. Malangizo a mayendedwe amatsimikiziridwa ndi kutentha kwamadzi. Nsomba za tuna zimakonda kukhala m'madzi otentha mpaka 18-25 ° C.
Pamene tikusaka m'magulu, tuna apanga njira yosavuta komanso yothandiza. Amayenda mozungulira sukulu ya nsomba zazing'ono pamphindi, zomwe amapita kukadya. Kenako amaukira mwachangu. Liwiro lakuukira ndi kuyamwa kwa nsombazi ndilopamwamba kwambiri. M'kanthawi kochepa, tuna amadya sukulu yonse yodya nyama.
M'zaka za zana la 19, asodzi anazindikira mphamvu ya tuna zhora. Anazindikira kuti nsombazi ndizopikisana nawo. Kuchokera kugombe lakum'mawa kwa America, komwe kuli nsomba zambiri, adayamba kuwedza nsomba kuti ateteze nsomba. Mpaka pakati pa zaka za zana la 20, nyama ya tuna inali yamtengo wapatali ndipo imagwiritsidwa ntchito popanga chakudya cha nyama.
Zakudya zabwino
Mitundu ya tuna amadyetsa zooplankton, amadya mphutsi ndi mwachangu za nsomba zina zomwe zapezeka mosazindikira m'dera la pelagic. Akamakula, nsomba za tuna zimasankha nyama zikuluzikulu ngati nyama. Makanema akuluakulu amaukira masukulu a herring, mackerel, ndikuwononga magulu onse a squid.
Kubereka ndi kutalika kwa moyo
Ma tunas onse ali ndi njira yosavuta yopulumutsira zamoyo: zimapanga mazira ochulukirapo. Mkazi mmodzi wamkulu amatha kutulutsa mazira okwana 10 miliyoni. Ma tunas aku Australia amatha kupanga mazira okwana 15 miliyoni.
Nsomba zam'nyanja za Tunayemwe amakula mochedwa. Mitundu ina imakwanitsa kubereka ana zaka 10 kapena kupitilira apo. Zaka za moyo za nsombazi sizikhala zazifupi, mpaka zaka 35. Akatswiri a sayansi ya zamoyo amati nsomba ya tuna yomwe imakhalapo kwa nthawi yayitali imatha kukhala zaka 50.
Mtengo
Tuna ndi nsomba yathanzi... Nyama yake imakondedwa kwambiri ku Japan. Kuchokera mdziko muno kumabwera nkhani za anthu okwera kumwamba omwe amafika mtengo wa tuna pamsika wogulitsa zinthu. Atolankhani nthawi ndi nthawi amafotokoza zamitengo yotsatirayi. Kuchuluka kwa US $ 900-1000 pa kg ya tuna sikuwonanso kosangalatsa.
M'masitolo ogulitsa nsomba ku Russia, mitengo ya tuna ndiyochepa. Mwachitsanzo, okwana nsomba atha kugulidwa ma ruble 150. Chidebe cha mazana awiri a nsomba zamzitini sichovuta kugula ma ruble 250 kapena kupitilira apo, kutengera mtundu wa tuna ndi dziko lopangira.
Kupha nsomba
Nsomba za Tuna anagwidwa chifukwa cha malonda. Kuphatikiza apo, ndi mutu wamasewera osodza ndi zikho. Kusodza nsomba m'mafakitale kwapita patsogolo kwambiri. M'zaka zapitazi, zombo za nsomba zinakonzedwanso.
M'zaka za m'ma 80, adayamba kupanga zida zamphamvu zopangira nsomba. Chida chachikulu pazombozi ndi chikwama cham'manja, chomwe chimadziwika ndikuthekera kwakumira kwamamita mazana ambiri ndikutha kukweza gulu laling'ono la tuna nthawi imodzi.
Mitundu yayikulu kwambiri ya tuna imagwidwa pogwiritsa ntchito ma longline. Iyi ndi ndowe, osati yolumikizidwa mochenjera. Osati kale kwambiri, kulumikizana kwa mbedza kunkagwiritsidwa ntchito m'mafamu ang'onoang'ono osodza. Tsopano akumanga zotengera zapadera - ma longliners.
Matayala - zingwe zingapo zolunjika (mizere), pomwe ma leashes ali ndi zingwe. Zidutswa za mnofu wa nsomba zimagwiritsidwa ntchito ngati nyambo yachilengedwe. Nthawi zambiri amapatsidwa ulusi wamitundumitundu kapena zofananira zina. Njira zophunzitsira nsomba za tuna zimathandizira kwambiri ntchito za asodzi.
Pogwira tuna, vuto lalikulu limabuka - nsombazi zimakhwima mochedwa. Mitundu ina imayenera kukhala ndi moyo zaka 10 isanabereke ana a tuna. Mgwirizano wapadziko lonse lapansi umakhazikitsa malire pa nsomba zazing'ono za tuna.
M'mayiko ambiri, ana saloledwa pansi pa mpeni kuti ateteze anthu a tuna ndikupanga ndalama. Amapita nawo kumafamu am'mphepete mwa nyanja komwe nsomba zimakulira mpaka kukula. Ntchito zachilengedwe komanso zamakampani zikuphatikizidwa kuti ziwonjezere nsomba.
