Rayuwar ruwa tana da ban sha'awa sosai don nazari kodayake an fi sani game da rayuwar ƙasa. Wannan ya sa son sani game da ƙaruwar teku ya ke kuma suna son yin nazarin dukkan nau'ikan da ke rayuwa a tekuna da tekuna. Ofayan ƙungiyoyin da ake buƙata a cikin karatun sune dabbobi masu shayarwa. Wadannan dabbobin sun samo asali ne daga dabbobin kasa wadanda suka dawo cikin teku kimanin shekaru miliyan 66 da suka gabata. Don rayuwa a cikin mahalli na ruwa, dole ne su haɓaka jerin sauye-sauye na kowane iri, kamar yadda za mu gani a cikin wannan labarin.
Shin kuna son sani game da dabbobi masu shayarwa? A cikin wannan sakon zamu gaya muku komai dalla-dalla.
Menene dabbobi masu shayarwa
Kimanin nau'ikan nau'ikan halittu masu dauke da halittun ruwa guda 120 ne ake hada su a cikin teku. Wadannan dabbobin ana tsammanin sun sami ci gaba ne ta hanyar sauye-sauye na tsarin motsa jiki domin su rayu a wadannan mahalli. Kamar yadda jinsunan da suka tashi a cikin tekuna zasu iya daidaitawa da rayuwar duniyar, akasin haka shima ya tashi.
A wannan yanayin, manufar da ta hada da dabbobi masu shayarwa tana da fadi sosai kuma ba wai kawai ta hada da nau'ikan da ke cikin wani rukunin haraji ba. Zamu raba dukkan dabbobin da muke daukarsu a matsayin dabbobi masu shayarwa:
- Ofungiyar cetaceans ta ƙunshi whales, porpoises da dolphins.
- Pinnipeds kamar walruses, like da otariums.
- Sirenians kamar dugongs da manatees.
- Otters kamar su otter da kuma cat cat.
- Tabbas, mun hada da polar bear da farin bear, wadanda ake daukarsu a matsayin dabbobi masu shayarwa, tunda yawancin ayyukansu ana aiwatar dasu ne a rayuwar teku. Hakanan suna da ikon kasancewa a cikin kankara a cikin teku kuma suna cin gajiyar su don farautar abincinsu.
Daga cikin wadannan dabbobin da muka bambanta a matsayin masu shayar da ruwa, zamu sami wasu da suke ciyar da rayuwarsu gaba daya a cikin Ruwa, yayin da wasu ke cikin wani tsari. Waɗanda ke cinye rayuwarsu gabaɗaya a cikin yanayin ruwan teku sune cetaceans da sirenians. Waɗannan su ne dabbobin da suka fi dacewa da rayuwar ruwan cikin wannan rukunin.
Kyakkyawan karfin fauna ne na waɗannan kafofin watsa labarai. Wannan ya haifar da mummunan amfani da ɗan adam ga waɗannan dabbobin. Saboda ayyukan mutane da suka shafi wadannan dabbobi masu shayarwa, akwai mutane da yawa masu rauni ko masu hatsari.
Daga ina suka fito?
Amfani da kasuwancin dabbobi masu shayarwa da mutane keyi saboda samun nama, kitse, mai, fata, hauren giwa har ma da nunawa kamar waɗanda muke samu a wasan dabbobi da kuma wasu gidajen namun daji na halittun ruwa.
Wadannan nau'ikan suna da aiki da tallafi na wasu kungiyoyin kare muhalli wadanda ke kokarin kiyaye yawan jama'a da rage barnar da aka yi musu. Ganin sha'awar wadannan dabbobi da kwarjinin da suka zubar, bukatar su san daga inda suka fito ya haifar da karatu da yawa a kai. Yawancin maganganun waɗannan karatun sun tabbatar da cewa tsoffin magabatan waɗannan dabbobi masu shayarwa Ana samun su a cikin tsohuwar Tekun Tethys shekaru miliyan 70 da suka gabata.
Wadannan kakannin da aka gano su ne suka haifar da kakannin halittun halittun ruwa da muke samu a yau. A bayyane yake, ba tare da halaye iri ɗaya ba tun lokacin da dabbobi ke canzawa akan lokaci. Ya danganta da yanayin muhallin da suke, suna iya inganta ci gaban wasu gabobin da ke basu damar rayuwa mafi kyau a cikin yanayi daban-daban.
Kodayake ba a fahimci matakan juyin halittar da suka sa wadannan dabbobi suka rayu mafi kyawu a wadannan muhallin ba, amma an san hakan su ba rukuni ne na son rai ba. Wannan yana nufin cewa ƙungiyoyi daban-daban sun tashi daga magabata daban-daban na duniya. An san wannan gaskiyar ne daga nazarin tsarin halittar mutum da burbushin halittu da kamanceceniya da su.
Ana tsammanin 'ya'yan dabbobin aladu aladu ne da shanu masu alaƙa da hanya mai nisa tare da hippos wanda zai iya haifar da ita. Kungiyoyin sun kasance suna amfani da halaye irin na zahiri, saboda bukatar dacewa da rayuwar teku. Wannan sananne ne da haɗuwar juyin halitta.
Karbuwa a cikin yanayin ruwa
Kamar yadda muka ambata a farkon labarin, don rayuwa a cikin yanayin ruwa, dole ne a ci gaba da sauye-sauye da tsarin aiki. Waɗannan sauye-sauye dole ne ya ba su damar zama a cikin yanayin ruwan. Don fahimtar waɗannan sauye-sauyen, ya zama dole a san cewa wannan matsakaiciyar tana da kaddarorin da suka bambanta da na yanayin duniya. Saboda haka, ya zama dole dabbar ta daidaita da ita kuma mafi sanin cewa ta fito ne daga rayuwar ƙasa.
Dalilin da yasa wasu dabbobi suka saba da zama a cikin teku yafi rikitarwa. Koyaya, dole ne ya zama akwai dalilai ga wasu daga cikin halittu masu shayarwa don ƙare rayuwa a cikin yanayin ruwan.
Wasu daga abubuwan karbuwa sun zo cikin shiri don iya jure nauyin ruwa wanda ya ninka na iska sau uku. Danko wani abu ne wanda zamu samu sau 60 danko ma a yanayi irin wannan. Waɗannan kaddarorin suna tasiri tasirin ƙarfi. Wani muhimmin mahimmin abin la'akari shine matsa lamba. Ruwan yana aiki sosai a cikin jiki wanda ke haifar da matsawa. Ga kowane mita 10 na zurfin matsa lamba ya fi girma.
Hakanan yanayin zafi yana da mahimmin mahimmanci don la'akari. Canjin yanayin zafi da makamashi yana raguwa yayin da zurfin ke karuwa.
Duk waɗannan canje-canjen a cikin yanayin rayuwa sun tilasta tilasta wasu canje-canje don su rayu a cikinsu. Wadannan karbuwa sun fara bayyana tsawon shekaru kuma sun dauki kimanin shekaru miliyan 60 kafin su cika. Har wa yau, har yanzu ana iya kammala su sosai.
Ina fatan cewa da wannan bayanin zaku iya sanin wani abu game da dabbobi masu shayarwa, asalinsu da kuma yadda suke rayuwa.