Mkango wa m'nyanja Ndi membala wamkulu kwambiri wabanja la Otariidae, "zisindikizo zowoneka", zomwe zimaphatikizapo mikango yam'madzi ndi zisindikizo zaubweya. Ndi yekhayo membala wa mtundu wa Eumetopias. Zisindikizo zowoneka mosiyanasiyana zimasiyana ndi ma molluscs, "zisindikizo zowona," pamaso pa mavavu akunja amakutu, mikono yayitali, yakutsogolo ngati mapiko yomwe imagwiritsidwa ntchito poyendetsera, ndikuzunguliza zipsepse zakumbuyo zomwe zimalola kuti mapazi anayi apite kumtunda.
Chiyambi cha mitundu ndi kufotokozera
Chithunzi: Sivuch
Mikango yam'nyanja, kapena zisindikizo zamakhungu, ndi amodzi mwamagulu atatu azinyama pagulu la taxonomic la pinnipeds. Pinnipeds ndi nyama zam'madzi (makamaka zam'madzi) zomwe zimadziwika ndi kupezeka kwa miyendo yakutsogolo ndi yakumbuyo ngati zipsepse. Kuphatikiza pa mikango yam'nyanja, ma pinniped ena amaphatikizanso ma walrus ndi zisindikizo.
Mikango yam'nyanja ndi amodzi mwamagulu awiri azisindikizo (pinnipeds zilizonse, kupatula ma walrusi): zisindikizo zopanda kanthu, zomwe zimaphatikizapo banja la taxonomic la zisindikizo zowona (Phocidae), ndi zisindikizo zamakutu, zomwe zimaphatikizaponso banja la zisindikizo zamakutu (Otariidae). Ma Walrus amadziwika kuti ndi banja losiyana la pinnipeds, Obobenidae, ngakhale nthawi zina amaphatikizidwa ndi ma molluscs.
Kanema: Sivuch
Njira imodzi yosiyanitsira magulu awiri azisindikizo ndi kudzera mu kupezeka kwa pinna, khutu laling'ono lamakutu (khutu lakunja) lomwe limapezeka mumikango yam'nyanja ndipo silimapezeka muzisindikizo zowona. Zisindikizo zenizeni zimatchedwa "zisindikizo zopanda makutu" chifukwa makutu awo ndi ovuta kuwona, ndipo mikango yam'nyanja imatchedwa "zisindikizo zamakhungu". Dzinalo otariid limachokera ku Greek otarion, kutanthauza khutu laling'ono, ponena za makutu ang'onoang'ono koma owoneka akunja (auricles).
Kuphatikiza pa kukhala ndi kaphalaphala, pali zosiyana zina zowonekera pakati pa mikango yam'nyanja ndi zisindikizo zowona. Mikango yam'nyanja ya Steller ili ndi zipsepse zakumbuyo zomwe zimatha kuzunguliridwa pansi pa thupi, kuwathandiza kuti ayende pansi, pomwe zipsepse zam'mbuyo zamatumba enieni sizingayendetsedwe pansi pamtembo, zomwe zimabweretsa kuyenda kwawo pang'onopang'ono komanso kovuta pansi.
Mikango yam'nyanja imasambiranso pogwiritsa ntchito zipsepse zawo zazitali zakutsogolo poyenda m'madzi, pomwe zisindikizo zenizeni zimasambira pogwiritsa ntchito ziboliboli zawo zam'mbuyo ndi thupi lawo pansi mozungulira. Palinso kusiyana kwamakhalidwe, kuphatikiza njira zoswana.
Maonekedwe ndi mawonekedwe
Chithunzi: Momwe mkango wam'madzi umawonekera
Mkango wam'madzi wa Steller wokhala ndi khungu lowala umatchedwa "mkango wanyanja" chifukwa cha kuwala kowala kwa tsitsi lolimba lomwe limapezeka pakhosi ndi pachifuwa champhongo, chofanana ndi mane a mkango. Nthawi zina imasokonezedwa ndi chidindo, koma ndikosavuta kudziwa kusiyana kwake. Mosiyana ndi zisindikizo, mphete zakunja kwa mkango wam'madzi zimatseka makutu awo kuziteteza kumadzi. Mikango yam'nyanja ya Steller ilinso ndi mawonekedwe olimba omwe amawalola kuti aziyenda pazipsepse zonse kwinaku akuzilemera kwathunthu.
Chosangalatsa ndichakuti: Monga mkango waukulu kwambiri panyanja, mkango wam'nyanja wachikulire umatha kutalika kwa mita ziwiri kapena zitatu. Amayi amalemera pakati pa 200 ndi 300 kilogalamu, pomwe amuna amapezeka kuti akulemera makilogalamu 800. Mkango umodzi waukulu wam'nyanja unkalemera pafupifupi tani imodzi.
Mwana wagalu wamkango wamba amakhala wolemera pafupifupi makilogalamu 20 akabadwa. Pakubadwa, ana agalu a mkango wa Steller amakhala ndi ubweya wakuda, wakhakula, pafupifupi wakuda wakuda ndi mawonekedwe achisanu, chifukwa malekezero a tsitsi alibe mtundu. Mtundu umawala pambuyo pa molt woyamba kumapeto kwa chilimwe. Amayi achikulire ambiri amakhala obiriwira kumbuyo. Pafupifupi amuna onse amakhalabe akuda kutsogolo kwa khosi ndi chifuwa, ena amakhala ofiira. Amuna akuluakulu amakhala ndi mphumi komanso khosi lalikulu.
Chosangalatsa ndichakuti: M'madzi, mkango wam'nyanja umasambira ndi bere ndipo umatha kufika pafupifupi 27 km / h.
Phokoso la mkango wapanyanja ndi gulu la "kubangula" kwanthawi yayitali kwa okalamba, kuphatikiza ndi "mwanawankhosa" wololera ana agalu. Mikango yam'nyanja yaku California imamveka nthawi zambiri pakati pa mikango yam'mwera chakum'mawa chakum'mawa kwa Alaska, ndipo kulira kwawo kodziwikirako ndikudziwitsa za mikango yaying'ono yakuda iyi.
Kodi mkango wam'madzi umakhala kuti?
Chithunzi: Kamchatka sea lion
Mikango yam'nyanja imakonda nyengo yozizira, yotentha kuposa madzi akumwera kwa Nyanja ya Pacific Pacific. Amafuna malo okhala kumtunda ndi m'madzi. Zimakumanirana ndi kuberekana pamtunda, m'malo achikhalidwe omwe amatchedwa malo achinyama. Zipinda zamphesa nthawi zambiri zimakhala ndi magombe (miyala, miyala kapena mchenga), zingwe, ndi miyala yamiyala. M'nyanja za Bering ndi Okhotsk, mikango yam'nyanja imathanso kukoka ayezi wanyanja. Ku North Pacific, malo okhala mikango yam'nyanja amatha kupezeka m'mbali mwa gombe la California kupita ku Bering Strait, komanso m'mphepete mwa Asia ndi Japan.
Chiwerengero cha anthu padziko lonse lapansi chagawika m'magulu awiri:
- kummawa;
- kumadzulo.
Mikango yam'nyanja imagawidwa makamaka pagombe la North Pacific Ocean kuchokera kumpoto kwa Hokkaido, Japan kudzera kuzilumba za Kuril ndi Nyanja ya Okhotsk, zilumba za Aleutian ndi Nyanja ya Bering, gombe lakumwera kwa Alaska ndi kumwera mpaka pakati pa California. Ngakhale amapezeka m'madzi a m'mphepete mwa nyanja kuchokera pashelefu, nthawi zina amapita kumalo otsetsereka ozama komanso m'madzi a pelagic, makamaka nthawi yopanda kuswana.
Nzika zaku Canada ndi gawo la anthu akum'mawa. Ku Canada, zilumba zomwe zili m'mphepete mwa nyanja ku British Columbia zili ndi malo atatu osankhira mikango yam'nyanja, yomwe ili pazilumba za Scott Islands, Cape St. James komanso pagombe la zilumba za Banks. Mu 2002, ana agalu pafupifupi 3,400 adabadwa ku British Columbia. Munthawi yakubereketsa, ziweto zonse zomwe zimapezeka m'madzi am'mphepete mwa nyanjazi ndi pafupifupi 19,000, ndipo pafupifupi 7,600 za nyamazo zimakhala zamsinkhu. Ndi mtundu wamphongo wamphamvu kwambiri wokhala ndi akazi angapo.
Mikango yam'nyanja ya Steller imaswana kunyanja ya North Pacific kuchokera pachilumba cha Año Nuevo chapakati pa California kupita kuzilumba za Kuril kumpoto kwa Japan, komwe kumakhala malo ambiri okhala ku Gulf of Alaska ndi kuzilumba za Aleutian.
Tsopano inu mukudziwa kumene mkango wa nyanja umapezeka. Tiyeni tiwone chomwe chidindo ichi chimadya.
Kodi mkango umadya chiyani?
Chithunzi: Mkango wanyanja
Mikango yam'nyanja ndi nyama zodya mano ndi nsagwada zolimba zomwe zimadya nyama yawo. Amagwira nsomba zawo ndipo amadya zilizonse zomwe zimapezeka mosavuta m'dera lawo. Ku British Columbia, mkango wam'nyanja makamaka umadya nsomba zamasukulu monga hering'i, hake, nsomba ndi sardini. Nthawi zina amalumphira pansi kuti agwire bass, flounder, squid ndi octopus.
Chosangalatsa: Mikango yam'nyanja ndi osambira abwino omwe nthawi zina amalowa m'madzi kupitirira ma 350 mita kufunafuna chakudya ndipo nthawi zambiri amangokhala m'madzi osapitirira mphindi zisanu nthawi imodzi.
Mikango yam'nyanja yayikulu imadya nsomba zamitundumitundu, kuphatikiza Pacific hering'i, gerbil, Atka mackerel, pollock, salimoni, cod ndi rockfish. Amadyanso octopus ndi squid wina. Pafupifupi, mkango wamkulu wam'nyanja umafunikira pafupifupi 6% ya kulemera kwake tsiku lililonse. Mikango yaing'ono yam'nyanja imafuna chakudya chowirikiza kawiri.
Mikango yam'nyanja imapheranso zisindikizo ndi nyama zina. Pazilumba za Pribilof, mikango yamphongo yaying'ono yamamuna yawonedwa ikupha ndikudya ana agalu akummwera akumpoto, pomwe kwina idadya zisindikizo zokhazokha. Chifukwa chakudya kwawo, mikango yam'nyanja imatha kukhudza nsomba, ma bivalve molluscs, gastropods ndi cephalopods.
Makhalidwe ndi mawonekedwe
Chithunzi: Mkango wam'nyanja wa Steller m'chilengedwe
Mikango yam'nyanja ndizinyama, choncho amafunika kubwera pamwamba kuti apume mpweya. Amathera nthawi yawo kumtunda ndikupita kumadzi kukasaka chakudya. Mikango yam'nyanja imakonda malo okhala m'mphepete mwa nyanja mkati mwa 45 km ya gombe, ngakhale imapezeka pamtunda wopitilira 100 km m'madzi ozama kupitirira mita 2000. Samasuntha ngati zisindikizo zina, koma amasuntha nyengo ndi nyengo kumalo osiyanasiyana odyetsera ndi opumulira.
Mikango yam'nyanja nthawi zambiri imakonda kucheza ndipo imakumana m'magulu akulu pagombe kapena malo osungiramo nyama. Nthawi zambiri amakhala m'magulu awiri mpaka khumi ndi awiri, koma nthawi zina mpaka anthu zana amapezeka limodzi. Panyanja, amakhala okha kapena amasuntha m'magulu ang'onoang'ono. Amadyera usiku pagombe komanso m'madzi a pelagic. Mikango yam'nyanja imatha kuyenda maulendo ataliatali m'nyengoyi ndipo imatha kulowa m'madzi akuya mamita 400. Amagwiritsa ntchito malowo ngati malo opumulirako, ogundizana, okwatirana ndi kuberekana. Mikango yam'nyanja imatulutsa mawu amphamvu, limodzi ndi kugwedeza mutu kwa amuna.
Kuswana mikango yam'nyanja ndiimodzi mwazinthu zodziwika bwino kwambiri m'chilengedwe. Zimphona izi zikagwa pagombe, magombe omwe amawakonda, omwe amatchedwa rookeries, amatha pansi pa matupi awo. Ana aang'ono nthawi zina amatenthedwa ndi unyinji, ndipo samamvedwa ndi amuna amphamvu okhala ndi cholinga chimodzi. Amuna ayenera kukhazikitsa ndi kusamalira malo kuti azitha kuswana. Ambiri aiwo samachita izi mpaka atakwanitsa zaka zisanu ndi zinayi kapena khumi.
Kakhalidwe ndi kubereka
Chithunzi: Mkango wam'madzi wa Steller m'madzi
Mikango yam'nyanja ndi obala achikoloni. Amakhala ndi njira yodzikongoletsera yopanda tinthu ting'onoting'ono momwe timagulu tating'onoting'ono tomwe timatulutsa ana agalu nthawi zina pachaka.
Nthawi yokomana ndi mkango wam'nyanja imayamba kuyambira kumapeto kwa Meyi mpaka koyambirira kwa Julayi. Pakadali pano, mkazi amabwerera kunyumba kwake - thanthwe lakutali, komwe achikulire amasonkhana kuti akwatirane ndi kubereka - kuti abereke mwana wagalu. M'nyengo yokhwima, mikango yam'nyanja imasonkhana m'magulu akuluakulu kuti atetezeke, kutali ndi nyama zolusa. Phokoso la achikulire komanso kulira kwa ana agalu omwe abadwa kumene zimapanga phokoso loteteza. Phokoso ili limodzi komanso losasunthika limawopseza adani omwe angakhalepo.
Mkango wamkazi wam'nyanja umasamalira mwana wake wagalu kwa chaka chimodzi kapena zitatu. Mayiyo amakhala kumtunda ndi ana awo tsiku limodzi kenako amapita kunyanja kukatenga chakudya tsiku lotsatira. Amatsatira ndondomekoyi kudyetsa ana ake kwinaku akupitirizabe kudya zakudya zake.
Mkango wam'nyanja wobadwa kumene ndi cholengedwa chodekha. Amatha kukwawa kuyambira atabadwa ndikuphunzira kusambira atakwanitsa milungu inayi yakubadwa. Ngakhale kuli kovuta kuwunika, zikuwoneka kuti kuchuluka kwa ana agalu amafa kwambiri ndipo atha kukhala chifukwa chakuchulukana kwa ziweto zakale kapena akakakamizidwa kuchoka pamalowo, sangathe kusambira ndikumira.
Ana agalu amakhala ndi chitetezo chamatenda ambiri akamayamwitsa. Ana agalu akamakula komanso kuyamwa, amatha kudwala tizilomboti (monga ziphuphu zozungulira) ndi tapeworm) zomwe zimakhudza kukula ndi moyo wautali. Mkango wachikazi wam'madzi umadziwa bwino zosowa za mwana wake wamwamuna, osamusiya kwa nthawi yoposa tsiku limodzi, m'mwezi woyamba wovuta wamoyo wake.
Adani achilengedwe a mikango yam'nyanja
Chithunzi: Sea Lion Steller
Kwa zaka zambiri, zochita za anthu monga kusaka ndi kupha zakhala zoopsa kwambiri kwa mikango yam'nyanja. Mwamwayi, izi ndizonso ngozi zomwe zitha kupewedwa. Nyama yayikuluyi imakhalanso pachiwopsezo cha zida zausodzi ndipo imatha kutsamwa ndi zinyalala m'khosi mwawo. Mkango wa m'nyanja wokakamira ukhoza kumira usanathe kuthawa kapena kudzimasula.
Kuwonongeka, kuwonongeka kwa mafuta, komanso kuwonongeka kwa chilengedwe monga zida zolemera zimawopseza malo okhala ndi mikango yam'nyanja. Kuwonongeka kotereku kumatha kubweretsa kusamutsidwa kwa okhala m'malo awo ofunikira ndipo, pamapeto pake, kuchepa kwa chiwerengero chawo.
Mkango wam'madzi umakumananso ndi ziwopsezo zachilengedwe, monga kuchepa kwa chakudya chomwe chilipo. Kuphatikiza apo, anamgumi opha amawasaka. Mofanana ndi nyama zonse, matendawa amakhala pachiwopsezo cha mikango yam'nyanja.
Asayansi pakadali pano akufufuza chifukwa chomwe kuchuluka kwa mikango yam'madzi ikuchepa. Zifukwa zomwe zingapangitse izi zikuphatikiza kuchuluka kwa tiziromboti, matenda, kudyedwa kwa anamgumi opha nyama, chakudya ndi kagawidwe, zinthu zachilengedwe, komanso kuperewera kwa zakudya m'thupi zomwe zimayambitsidwa ndikusintha kwachilengedwe pakukula kwa mitundu yayikulu ya nyama kapena mpikisano ndi mitundu ina ya anthu kapena chakudya.
Chiwerengero cha anthu komanso mtundu wa mitunduyi
Chithunzi: Momwe mkango wam'madzi umawonekera
Mitundu iwiri yamikango yam'nyanja ikuyimira mitundu yosiyanasiyana ya majini, morphological, zachilengedwe komanso kuchuluka kwa anthu. Kuchuluka kwa kuchuluka kwa anthu kum'mawa ndi kumadzulo kwa anthu kumasiyana pazifukwa zovuta. M'mawu osavuta, kusiyana kumeneku mwina chifukwa cha mitundu yosiyanasiyana ndi kukula kwa ziwopsezo zomwe mtunduwo umakumana nawo pamtunda wake wonse.
Anthu akumadzulo akuphatikiza mikango yonse yam'nyanja yochokera kumalo osungira nyama kumadzulo kwa Sakling Point. Kuchuluka kwa mikango yam'nyanja kunatsika kuchoka pa 220,000 mpaka 265,000 kumapeto kwa ma 1970 mpaka ochepera 50,000 mu 2000. Pomwe anthu akumadzulo akukulira pang'onopang'ono kuyambira cha 2003, ikucheperachepera mwachangu m'malo akulu akulu.
Anthu akum'maŵa akuphatikizapo mikango yam'nyanja yochokera kumalo osungira nyama kum'mawa kwa Sakling Point. Pakati pa 1989 ndi 2015, kuchuluka kwawo kummawa kudakwera 4.76% pachaka, kutengera kusanthula kwa ana agalu ku California, Oregon, British Columbia ndi kumwera chakum'mawa kwa Alaska. Oposa 80% yamikango yam'nyanja yasowa ku Russia komanso madzi ambiri aku Alaska (Gulf of Alaska ndi Bering Sea) pakati pa 1980 ndi 2000, ndikusiya anthu ochepera 55,000. Mikango yam'nyanja ili mu Red Book ngati yomwe ili pachiwopsezo chotha posachedwa.
Zopseza mikango yam'nyanja zimaphatikizapo:
- kuwomba kuchokera bwato kapena sitima;
- kuipitsa;
- kuwononga malo;
- kusaka kapena kuwombera kosaloledwa;
- Kufufuza mafuta ndi gasi wakunyanja;
- kulumikizana (molunjika kapena molunjika) ndi nsomba.
Zomwe zimakhudza kwambiri usodziwu makamaka zimachokera ku zida zamagalimoto (zoyendetsa ndi ma gillnets, ma longline, ma trawls, ndi zina zambiri) zomwe zimatha kumangirira, kukwapula, kuvulaza kapena kupha mikango yam'nyanja. Adawoneka atatengeka ndi zida zausodzi, zomwe zimawoneka ngati "kuvulala kwakukulu." Zovuta zina zakusodza zimaphatikizaponso kufunikira kokakamira kupezera chakudya ndikusintha malo okhala chifukwa cha ntchito zausodzi.
M'mbuyomu, ziwopsezo zidaphatikizapo:
- kusaka nyama zawo, zikopa, mafuta ndi zinthu zina zosiyanasiyana (m'ma 1800);
- kupha munthu wolipiritsa (koyambirira kwa ma 1900);
- kupha kuti ateteze nsomba zawo m'nyanja (m'minda ya nsomba). Koma kupha dala mikango yam'nyanja sikunaloledwe popeza adatetezedwa pansi pa Marine Mammal Protection Act.
Chitetezo cha mkango wa m'nyanja ya Steller
Chithunzi: Sivuch kuchokera ku Red Book
Pofuna kupititsa patsogolo kuchuluka kwawo, mikango yam'nyanja imafunikira kuteteza malo awo. Ngakhale mkango wanyanja ku Canada wavutikira zaka zambiri ukusaka, kuyambira 1970 watetezedwa pansi pa Federal Fisheries Act, yomwe imaletsa kusaka kwamikango yam'nyanja. Pakhala pali milandu pomwe ziphaso zoperekedwa kuti aphe mikango yam'nyanja pofuna kuteteza minda ya nsomba yomwe nyama zimasaka.
Lamulo la m'nyanja, lomwe lidakhazikitsidwa mu 1996, limateteza malo okhala nyama zam'madzi. Malo apadera obereketsa amakhala ndi chitetezo china pansi pa National Parks Act of Canada komanso ngati gawo la Reserve Ecological Reserve.
Madera otetezera, malire, njira zosiyanasiyana ndi njira zina zayambitsidwa mozungulira nsomba zazikuluzikulu komanso malo okhala ndi mikango yam'nyanja kuteteza malo awo ovuta.Malo okhala ovuta apatsidwa kwa mikango yam'nyanja ngati cholumikizira makilomita 32 mozungulira malo onse opha nyama, komanso malo awo, mlengalenga ndi m'madzi komanso madera atatu akuluakulu am'madzi. National Marine Fisheries Service yatchulanso malo oletsedwa mozungulira malo ogulitsira ndikukhazikitsa njira zowongolerera zausodzi zomwe zapangidwa kuti muchepetse mpikisano pakati pa asodzi ndi mikango yomwe ili pachiwopsezo m'malo okhala ovuta.
Mkango wa m'nyanja amatchedwa "mfumu" yamikango yam'nyanja. Nyama yothanzayi nthawi zambiri imayenda yokha kapena m'magulu ang'onoang'ono, koma imalumikizana ndi ena kuti itetezedwe mukamakhalira ndi kubereka. Zing'onozing'ono sizikudziwika za moyo wawo wam'nyanja, komabe, chosangalatsa ndichakuti kuyambira pomwe mkango wam'madzi udatetezedwa koyamba mu 1970, anthu achikulire awirikiza kawiri.
Tsiku lofalitsa: 12.10.2019
Idasinthidwa: 29.08.2019 pa 23:31
