Amphibians suav nrog cov vertebrates vertebrates Lawv lub npe txhais tias "ob lub neej" (amphi=ob leeg thiab bios=life) thiab Lawv yog cov tsiaj ectothermic, uas yog, lawv nyob ntawm cov khoom siv hluav taws xob sab nraud los tswj lawv qhov sib npaug sab hauv. Tsis tas li ntawd, lawv yog anamniotes, zoo li ntses; Qhov no txhais tau hais tias lawv cov embryos tsis muaj daim nyias nyias uas nyob ib puag ncig lawv: lub amnion.
Ntawm qhov tod tes, kev hloov pauv ntawm amphibians thiab lawv txoj kev hla dej mus rau thaj av tau tshwm sim ntau lab xyoo. Lawv cov poj koob yawm txwv nyob txog 350 lab xyoo dhau los, nyob rau hauv lub lig Devonian, thiab lawv lub cev yog stocky thiab lawv ob txhais ceg tau dav thiab flattened nrog ntau tus ntiv taw. Cov no yog Acanthostega thiab Icthyostega, uas yog cov thawj ntawm tag nrho cov tetrapods peb paub niaj hnub no. Lawv muaj kev faib tawm thoob ntiaj teb, txawm hais tias lawv tsis nyob hauv thaj chaw suab puam, hauv cheeb tsam polar thiab Antarctic thiab hauv qee thaj chaw dej hiav txwv. Txuas ntxiv nyeem tsab xov xwm no ntawm peb lub xaib thiab koj yuav kawm txog txhua yam yam ntxwv ntawm amphibians, lawv peculiarities thiab kev ua neej.
Dab tsi yog amphibians?
Amphibians yog tetrapod vertebrate tsiaj, uas yog, lawv muaj pob txha thiab plaub ceg ceg. Qhov no yog ib pab pawg neeg tshwj xeeb tshaj plaws ntawm cov tsiaj, txij li thaum lawv dhau los ua metamorphosis uas tso cai rau lawv mus ntawm theem larval mus rau theem neeg laus, uas txhais tau hais tias thoob plaws hauv lawv lub neej lawv muaj ntau yam kev ua pa.
Type of amphibians
Muaj peb hom amphibians, uas yog cais raws li nram no:
- Amphibians ntawm qhov kev txiav txim Gymnophiona: nyob rau hauv pawg no tsuas muaj caecilians, uas nws lub cev zoo li ib tug cab, tab sis muaj plaub ceg luv heev.
- Amphibians of the order Caudata: yog tag nrho cov amphibians uas muaj tus Tsov tus tw, xws li salamanders thiab newts.
- Amphibians of the order Anura: lawv tsis muaj tail thiab paub zoo tshaj. Qee qhov piv txwv yog qav thiab toads.
Cov yam ntxwv tseem ceeb ntawm amphibians
Ntawm cov yam ntxwv ntawm amphibians, cov hauv qab no sawv tawm:
Cov metamorphosis ntawm amphibians
Amphibians muaj qee yam peculiarities hauv lawv txoj kev ua neej. Tsis zoo li lwm tus ntawm tetrapods, lawv tau dhau los ua cov txheej txheem hu ua metamorphosis uas tus larva, uas yog, tadpole, ua neeg laus thiab dhau los ntawm gill ua pa mus rau pulmonary.. Thaum lub sijhawm txheej txheem no, txhua yam kev hloov pauv ntawm cov qauv thiab lub cev muaj zog tshwm sim, uas lub cev npaj kom dhau los ntawm cov dej mus rau lub neej hauv av.
Lub qe amphibian muab tso rau hauv dej, yog li thaum tus larva hatched nws muaj gills ua pa, tus Tsov tus tw thiab lub qhov ncauj ncig rau noj. Tom qab qee lub sij hawm siv hauv dej, nws yuav npaj txhij rau metamorphosis, qhov twg nws tau hloov pauv ntau yam xws li ploj ntawm tus Tsov tus tw thiab gills, zoo li hauv qee cov salamanders (Urodelos), kom muaj kev hloov pauv hauv lub cev, xws li hauv Qav (Anurans). Kuj cov hauv qab no tshwm sim:
- kev loj hlob ntawm Bony Skeleton.
- Lung growth.
- Differentiation of pob ntseg thiab qhov muag.
- Txoj kev loj hlob ntawm lwm yam kabmob thiab kev nkag siab.
- Neural development.
Txawm li cas los xij, qee hom salamander tuaj yeem ua yam tsis muaj metamorphosis thiab mus txog rau theem neeg laus nrog cov yam ntxwv larval, xws li muaj cov gills, yog li ntawd. nws yuav zoo li ib tug neeg laus. Cov txheej txheem no hu ua neoteny.
Nkauj tawm tshiab
Tag nrho cov amphibians niaj hnub no, uas yog, Urodelos los yog Caudata (salamanders), Anuros (qav) thiab Gimnofiona (caecilians), yog collectively hu ua Lissanphibia, thiab lub npe no muab los ntawm qhov tseeb hais tias cov tsiaj notsis muaj nplai rau ntawm daim tawv nqaij, yog li ntawd lawv yog "liab qab". Lawv tsis muaj lwm yam dermal npog zoo li lwm cov vertebrates, yog cov plaub hau, plaub los yog nplai, tshwj tsis yog cov caecilians, nws daim tawv nqaij yog them los ntawm ib hom "dermal scale"
Ntawm qhov tod tes, nws daim tawv nqaij nyias nyias, uas pab kom cov tawv nqaij ua pa, nws yog permeable thiab muaj cov nplua nuj vascularization., pigments thiab qog (qee zaum muaj tshuaj lom) uas tso cai rau lawv tiv thaiv lawv tus kheej tiv thaiv kev puas tsuaj los ntawm ib puag ncig thiab tawm tsam lwm tus neeg, los ntawm kev ua lawv thawj kab ntawm kev tiv thaiv.
Ntau hom, xws li dendrobatids (xob xub qav), muaj uas tso cai rau lawv muab "ceeb toom" rau lawv cov tsiaj nyeg, vim lawv txawv heev, tab sis cov xim no yuav luag ib txwm cuam tshuam nrog cov qog ua kua qaub. Qhov no, nyob rau hauv qhov xwm txheej, yog hu ua tsiaj aposematism, uas yog qhov tseem ceeb ceeb toom xim.
Amphibian skeleton and libs
Cov tsiaj no muaj qhov sib txawv ntawm nws cov pob txha nrog rau lwm cov vertebrates. Thaum lawv evolution lawv tau poob thiab hloov ntau cov pob txha ntawm lub forelimbs, tab sis nyob rau hauv cov ntaub ntawv ntawm lub duav rov sauv, nws yog heev tsim.
Lub forelegs muaj plaub ntiv taw thiab ob txhais ceg tsib, thiab yog elongated rau lub dhia los yog ua luam dej, tsuas yog hauv caecilians, uas tau poob lawv cov ceg tawv vim lawv txoj kev ua neej fossorial. Ntawm qhov tod tes, nyob ntawm hom, hind ob txhais ceg tuaj yeem hloov kho ob qho tib si rau kev dhia thiab ua luam dej, tab sis kuj rau kev taug kev.
Npau suav teb
Lub qhov ncauj ntawm amphibians yog tus yam ntxwv muaj cov hauv qab no:
- cov hniav tsis muaj zog.
- Nkauj thiab dav.
Tus nplaig ntawm amphibians ua rau nws yooj yim rau lawv noj, thiab qee hom lawv tuaj yeem ua rau lawv sab nraud los ntes lawv cov tsiaj.
Nkauj tawm tshiab
Teb cov lus nug ntawm dab tsi amphibians noj yog qhov tsis meej meej, txij li kev pub mis ntawm amphibiansnws txawv raws hnub nyoog , muaj peev xwm pub Nyob rau hauv cov nroj tsuag dej nyob rau hauv lub larval theem, thiab nyob rau hauv me me invertebrates nyob rau hauv cov laus theem, xws li:
- Vim.
- Kab.
- Spiders.
Tseem muaj cov tsiaj txhu uas tuaj yeem noj tau me me vertebrates, xws li ntses thiab tsiaj txhu, piv txwv li, escuerzos (lawv pom nyob rau hauv cov pab pawg ntawm anurans) uas yog stalking neeg yos hav zoov thiab feem ntau suffocate sim nqos cov tsiaj uas loj heev.
Amphibian Respiration
Amphibians muaj gill respiration (nyob rau hauv lawv cov larval theem) thiab cutaneousua tsaug rau lawv cov tawv nqaij nyias thiab permeable, uas tso cai rau lawv hloov cov pa roj. Txawm li cas los xij, cov neeg laus kuj muaj kev ua pa ntsws, thiab hauv ntau hom lawv ua ke ob hom kev ua pa thoob plaws hauv lawv lub neej.
Ntawm qhov tod tes, qee hom salamanders tsis muaj lub ntsws ua pa, yog li lawv tsuas yog siv roj pauv los ntawm daim tawv nqaij xwb, thiab qhov no feem ntau yog folded, kom qhov chaw pauv pauv nce ntxiv.
Yog xav paub ntxiv, koj tuaj yeem sab laj lwm tsab xov xwm no ntawm peb qhov chaw hais txog Qhov twg thiab ua pa amphibians ua li cas?
Reproduction of amphibians
Amphibians muaj cov sib deev sib deev, uas yog, lawv yog dioecious, thiab qee zaus muaj kev sib deev dimorphism, uas txhais tau tias cov txiv neej thiab poj niam yog distinguishable. Feem ntau, fertilization yog sab nraud hauv anurans thiab sab hauv hauv urodeles thiab gymnophyans. Lawv yog cov oviparous thiab cov qe tso rau hauv dej los yog hauv cov av noo kom tsis txhob desiccation, tab sis nyob rau hauv cov ntaub ntawv ntawm salamanders, tus txiv neej tawm ib pob ntawm cov phev nyob rau hauv lub substrate, hu ua spermatophore, yuav tsum tau tom qab sau los ntawm tus poj niam.
Amphibian qe tso rau hauv foamy masses ua los ntawm niam txiv, thiab tej zaum yuav tiv thaiv los ntawm ib tuggelatinous membrane uas tseem tiv thaiv lawv tiv thaiv kab mob thiab cov tsiaj nyeg. Ntau hom muaj kev saib xyuas niam txiv, txawm tias lawv tsis tshua muaj, thiab tsuas yog thauj cov qe rau hauv lawv lub qhov ncauj lossis cov tadpoles ntawm lawv nraub qaum thiab txav mus yog tias muaj cov tsiaj txhu nyob ze.
Tsis tas li ntawd xwb, lawv muaj a cloaca, ib yam li cov tsiaj reptiles thiab noog, thiab nws yog los ntawm ib qho kev sib txuas uas tsim tawm thiab tso tawm..
Lwm yam ntxwv ntawm amphibians
Ntxiv rau cov yam ntxwv uas tau hais los saum no, amphibians kuj txawv ntawm cov hauv qab no:
- Peb-chambered heart: lawv muaj peb chav chambered, nrog ob lub atria thiab ib lub ventricle thiab ob chav ncig ntawm lub plawv. Koj daim tawv nqaij yog vascularized heev.
- Lawv ua tiav cov kev pabcuam ecosystem: txij thaum muaj ntau hom tsiaj noj kab uas tuaj yeem ua kab tsuag rau qee cov nroj tsuag lossis cov kab mob xws li yoov tshaj cum.
- Lawv yog cov tshuaj bioindicators zoo: Qee hom muaj peev xwm muab cov ntaub ntawv hais txog ib puag ncig uas lawv nyob, vim lawv khaws cov tshuaj lom lossis cov kab mob hauv lawv. tawv. Qhov no tau ua rau lawv cov pejxeem poob qis hauv ntau thaj tsam ntawm lub ntiaj teb.
- Great diversity of species: muaj ntau tshaj 8,000 hom amphibians nyob rau hauv lub ntiaj teb no, ntawm uas muaj ntau tshaj li 7,000 hom anurans, ib co 700 hom urodeles thiab ntau tshaj 200 sib haum mus rau gymnophynas.
- Endangered: Ntau hom tsiaj muaj kev phom sij lossis raug kev puas tsuaj los ntawm kev puas tsuaj ntawm lawv qhov chaw nyob thiab kab mob hu ua chytridiomycosis, tshwm sim los ntawm ib tug pathogenic chytrid fungus, Batrachochytrium dendrobatidis, uas yog drastically rhuav tshem nws cov pejxeem.
