Inhlanzi

Ngisho noma ungazi, izinhlanzi ziyiqembu elikhulu lezilwane ezinomgogodla, ezinezinhlobo ezicishe zibe ngu-28000 emhlabeni. Iningi labo lihlala olwandle, kodwa futhi lihlala emanzini ahlanzekile.

Kodwa, wazini ngezinhlanzi? Njengoba benjalo? Yiziphi izinhlobo zezinhlanzi ezikhona? Kulesi sigaba uzothola lonke ulwazi umthandi walezi zilwane angafuna ukwazi.

ziyini izinhlanzi

Izinhlanzi ziyiqembu elikhulu lezilwane ezihlala endaweni ehlala emanzini. Ubukhulu bawo bungahluka kakhulu, ngoba bangalinganisa ukusuka kumamilimitha ayi-8 kuye kwangamamitha angaphezu kuka-12. Isizathu sokuthi kungani uthola izinhlobonhlobo zazo. Ngaphandle kwalokho, Zijwayelane namazinga okushisa ahlukene emanzini, zikwazi ukuhlala ezindaweni ezisukela ku-40 degrees kuya ku-2.

Ngokuvamile, izinhlanzi ziyizilwane ezihlala emanzini. Ngokwe-anatomically, banendawo yobuchopho evikelwe ngebhokisi le-cranial futhi kuleyo ngxenye yomzimba wabo bafaka amehlo, amazinyo (umlomo) nezitho zezinzwa.

Ziyizilwane ezinomgogodla kanye ne-ectothermic. Okusho ukuthi, bangakwazi ukulawula izinga lokushisa lomzimba wabo ngokuziqondisa naleyo yendawo ezungezile.

Ngoba bahlala emanzini, akudingekile ukuba baphume kuwo ukuze baphefumule, kodwa sebenzisa ama-gill ukwenza kanjalo (ngabo bayakwazi ukumunca umoya-mpilo ochithwa ngamanzi). Ngaphezu kwalokho, wonke umzimba wayo umbozwe amazenga, ayivikela ngendlela ethile, futhi inamaphiko okuyiwo ekwazi ukuhamba ngawo ngokushesha noma ngaphansi endaweni ehlala emanzini.

Ilukuluku esingakutshela ngalo ngezinhlanzi limayelana neminyaka yazo. Njengezihlahla, izinhlanzi nazo zishiya uphawu olucacile lokuthi zineminyaka emingaki. Futhi ukuthi amasongo okukhula akhiwa okuyilawo anquma iminyaka leyo nhlanzi enayo.

izinzwa zezinhlanzi

Njengabantu, izinhlanzi nazo zinezinzwa. Nakuba ezinye zithuthuke kakhulu kunezinye.

Umuzwa wokubona akuyona enye yezimpahla zakho ezinhle kakhulu, kusukela, nakuba amehlo bewajwayela ukubona emanzini, awakwazi ukudlulisela ezinhlanzini uhlobo oluchazwe kahle lwalokho abakubonayo. Eqinisweni, lapho behlala phansi kakhulu, amehlo abo abi nakakhulu, ngokuphambene nalokho okwenzekayo ngalabo abaseduze kwendawo.

Kodwa-ke, kuzophinde kuncike ohlotsheni lwezinhlanzi, njengoba, isibonelo, izinhlanzi ezinamathambo zingakwazi ukuhlukanisa ngokucacile imibala yezinto ezizibonayo.

Nokho, futhi ngokuvamile, ayikho inhlanzi ekwazi ukubona ngokucacile imibala nezimo zezinto ezizungezile, yingakho, lapho izidoba, kuba lula ngoba azikwazi ngempela ukuhlukanisa kahle.

Umuzwa wokuthinta ezinhlanzini usekelwe entweni yezinzwa ebizwa ngokuthi umugqa osemaceleni. Lawa ama-sensory corpuscles agcwele umzimba wayo wonke, enza umugqa obonakalayo phakathi kwawo emaceleni. Lokhu kusebenza kokubili ukwazi umqondo wokuqondisa futhi, ngokusebenzisa amagagasi athusayo emanzini, ukwazi ukuthi kukhona yini izinto ezizungezile, ezinye izinhlanzi, njll.

Enye yezinzwa ezithuthuke kakhulu ezinhlanzini iphunga. Lokhu kutholakala engxenyeni engaphambili yekhanda, lapho inamakhala khona (ngaphandle kwezinhlanzi ze-cartilaginous ezinazo ngaphansi kobuso, endaweni yomlomo). Kwenzelweni? Nokho, bayisebenzisa ukuze bahlukanise izitha kanye nokufuna ukudla.

Inzwa yokuzwa ingenye yalezo esezithuthuke kangcono, njengoba inendlebe yangaphakathi ehlangana nesinye sokubhukuda. Lena ekhipha ukudlidliza kusukela, njengoba igcwele igesi, lapho indlebe idlulisa amaza omsindo, igesi iyanyakaza.

Eqinisweni, ngisho noma ungazi, zikhona izinhlanzi ezikwazi ukwenza imisindo. Lezi zifana ncamashí nokunswininiza, yingakho uma kuthiwa inhlanzi iyakhala, akudlalwa, wukuthi bayakwazi ngempela.

Ngaphezu kwalokho, izinhlanzi zixhumana ngomsindo, kuyindlela yokuxhumana, kokubili ukusungula ubuhlobo nezinye izinhlanzi nokwesabisa izitha zabo.

Ekugcineni, umuzwa wokunambitha awukho nje emlonyeni kuphela, kodwa nasekhanda, ingxenye yomzimba wabo, ezilevini zabo...

Umsuka wezinhlanzi

Izinhlanzi zaziwa ngokuthi zavela kuma-chordates ngesikhathi se-Cambrian. Kepha akwaziwa ngempela ukuthi imvelaphi yabo iyini, iqembu lakudala kakhulu kubo, lokho okubizwa ngokuthi ama-ostracoderms, lapho kwazalwa khona ama-agnath (izibani nezixube). Lezi zinhlanzi zazinezivikelo ezivikela ikhanda nengxenye yomboko wazo, yingakho kucatshangwa ukuthi zavela ngaleyo ndlela. Umgomo wabo kwakuwukuzivikela kwezinye izilwane ezidla ezinye ababehlala nazo endaweni eyodwa.

I-Ostracoderms yavuka futhi yazala ngokushesha, ingahlali olwandle kuphela, kodwa futhi nemifula namachibi. Kwakungenkathi yeDevoni lapho baqala ukushabalala. Kodwa, esikhundleni salokho, kwavela inhlanzi yokuqala, efana naleyo esiyaziyo manje.

Izinhlobo zezinhlanzi

Njengoba sishilo ngaphambili, Kunezinhlobo ezingaba ngu-28000 zezinhlobo zezilwane. Kodwa zonke zingahlukaniswa ngamaqembu amathathu amakhulu. Lezi izi:

i-ciclostoma

Baziwa kangcono ngokuthi izinhlanzi ezingenamhlathi Zinokwakheka kwakudala, ikakhulukazi kuhlaka lwamathambo. Futhi mhlawumbe bangabokuqala ukuvela futhi baye baqhubeka besosukwini lwethu nosuku. Zibonakala ngokuba nomzimba omise okwe-eel nomlomo onganyakazi. Kodwa egcwele amazinyo abukhali anezimpondo, akwazi ukuhlasela inyamazane yazo futhi azinamathisele kuyo ngenxa yenkomishi yokumunca eziyisebenzisayo, ngamazinyo, ilandisa kahle ngesisulu sazo.

ama-chondrichthyans

Kwaziwa kangcono ngokuthi inhlanzi enesigaxa. Lokhu kusho ukuthi anohlaka lwamathambo enziwe ngoqwanga, okubenza baguquguquke kakhulu. Inamapheya amabili amaphiko, i-scapular (noma yangaphambili) kanye ne-pelvic (noma ngemuva).

Njengeyangaphambili, nawo anamazinyo futhi iningi lawo lidla inyama, kodwa awavamisile ukuntanta njengezinye izinhlanzi. Lokhu kungenxa yokuthi abanaso esinyeni sokubhukuda.

I-Osteichthyos

ebizwa izinhlanzi ezinamathambo. Ziyizinhlanzi ezinohlaka lwamathambo oluphelele, futhi ziyinqwaba kuzo zonke izinhlobo zezilwane. Iqiniso liwukuthi ngokuma komzimba ziyahlukahluka kakhulu, kanye nekhanda, amaphiko, izikali ...

Yiqiniso, lezi zinhlanzi azinawo amazinyo.