Chokwadi chikuru, chakataurwa zviuru zvenguva, ndechekuti "zvisikwa zvakangwara uye zvakanyatsojeka", pfungwa isiri kukurukurwa, uye zvakanyanya kana iwe uchifanira kutaura nezve zvinoshamisa magadzirirwo uye kubereka masisitimu anowanikwa mukati. mhuka kuti hupenyu huvepo mune dzimwe nzvimbo. Chimwe chezvipenyu izvi ovoviviparous mhuka, dzine marongero chaiwo ayo.
Tsanangudzo pfupi yemhuka ovoviviparous
Mhuka dzemhando idzi dzinoenderana nedzinokura mukati mezai nguva refu isati yazvarwa, zvichidzisiyanisa nedzimwe. Mhando dzemhuka umo zai rinobatwa mukati nerudzi rwechikadzi kusvikira embryo yanyatsoumbwa. Pasi peizvi, mhuka inoputsa nzvimbo yekudzivirira nokukurumidza pamagumo ayo akaiswa. Panewo nyaya yekuti kunze kwemuviri wemukadzi uyezve kuberekwa kwemwana kunoitika.
Ovoviparity kana ovoviparism, kunyanya, kuumbwa pakati pe oviparism, iyo inobata nemhuka dzinokandira mazai kuti dzibereke, uye viviparism, iyo inoreva mhuka dzinoumbwa mukati maamai. Icho, chaizvoizvo, muenzaniso wakakwana wegadziriro yemhindumupindu yakaitika kupfurikidza nokurarama, uko kwakaparira kuchinja kwemavara okugara nhaka.
Zvimwe zvakasiyana zve ovoviviparous
Pakati pezvimwe zvakasarudzika izvo the ovoviviparous mhuka neruremekedzo kune zvimwe zvisikwa ndezvokuti, vanowana kuti mazai avo anogona kukura mukati mezai uye ari mukati memukadzi wemarudzi, kusiyana neoviparous, iyo inoisa mazai mune imwe nzvimbo uye kunze kubva kuna amai pakutanga kukudziridza embryo, uye gare gare, kuberekwa kubva mairi.
Zvakakosha kusimbisa iyo viviparous mhuka, zvinova izvo zvipenyu, izvo chibereko chiri kuumba mukati mechimiro chemukadzi, pamwe chete nemhuka dzinoyamwisa. Zvisinei, the viviparous vanokwanisa kuva nekamwana kanenge kachangobva kunambwa nechomukati, pane musiyano unokosha, izvo zvinoratidza kuti sezvo yakadzivirirwa nedemhe, haigoni kuwana zvakananga zvokudya zvingava naamai.
Ovoviviparous inobereka sei?
Fertilization inoitika mukati, sekukura kweembryo, nekusiyana kukuru kwemhuka viviparous, iyo isingakure mukati mezai, kunyanya kana yakadzivirirwa nehadzi. Mwana weramangwana, ari mukati mezai, anokwanisa kudya uye kushandisa zvinovaka muviri zvose zvaanopiwa nesero rimwe chetero. Muzvisikwa, kunewo mhuka apo hadzi inosunungura zai, richimirira kuti riputse uye, kana izvi zvangoitwa, hadzi inodzidzivirira kusvikira dzava kukwanisa kuzviriritira.
Ovoviviparous iripo munyika
Mukati meboka duku iri unogona kuwana mhuka dzinonyatsozivikanwa, pamwe chete nedzimwe dzisina kukosha, asi dzisina kukosha kune iyo. kutsanangura nezve zvimwe ovoviviparous mhuka, inogona kutsanangurwa:
White shark: Inofambirana nerudzi rwe silky shark yehukuru hukuru uye simba, ine muromo wakaita arch uye mazino anochinja. Anofanira kushambira nguva dzose, sezvo zvisingabviri kuti arambe akanyarara, sezvo kusaita kudaro kunomutadzisa kufema uyewo, kukuyangarara, achiziva kuti haana dundira rokutuhwina. Fetuses inodyiswa kuburikidza ne vitellium; haikwanisi kuisa mazai kunze, asi vana vanoberekerwa mukati meamai uye gare gare, pavanobuda, ivo vakatogadzirwa.
Boa constrictor: Inogona kutsanangurwa semhuka ine hurefu huri pakati pe 0,5 ne 4 mamita, zvichienderana neboka rayo. Kutaura zvazviri, hadzi dzinosvika pakukura kudarika varume. Rudzi rwayo rweruvara rwakatsvuka uye ruchena, kana kuti shava uye dzvuku, paine misiyano yakati maererano neari kutaurwa. Inowanzoita kuti ibereke munguva yekunaya kwemvura, ichipedza mwedzi mishomanana yekukura kwayo uye kuberekwa kwayo kunoitika mukati megadziriro yaamai, inenge yatokura zvakakwana.
Manta ray (giant manta): Inosiyana nedzimwe mhuka pakuti haina chepfu inoruma mumuswe wayo, pamwe chete nekukura kwainogona kusvika. Inowanzo kuwanikwa mumakungwa ane mwero, inokwanisa kusvetuka kubva mumvura. Panguva iyo kubereka kunoitika, vamwe varume vanotsvaga kukunda munhukadzi, chimwe chezvinodikanwa zvekutevedzera kuve kuuraya makwikwi. Vanogona kuva kwemwedzi gumi nembiri vari mukati maamai.
Anaconda: Iyo iri mukati merudzi rwe constrictor nyoka, inokwanisa kuyera, mune yakakura kesi, gumi metres pakureba. Kunyange zvazvo isiri muboka asi nenzira yokusashamwaridzana, hadzi painotsvaka kubereka, inokwanisa kuroya murume nokudzinga mapheromones. Muboka rimwe nerimwe revana, huwandu huri pakati pe20 ne40 marudzi anoumbwa, nehurefu hunosvika 60 centimita.
Surinam Toad: Inofambirana neamphibian inowanikwa munzvimbo dzinopisa uye dzinopisa. Pakati pezvazvinoita muviri wayo wakatsetseka uye musoro wayo une mativi matatu uye wakatsetseka. Ganda rake rakaita grey uye rakasvibira rakajeka pasi. Panyaya iyi, inoshamisa zvikuru mukati me ovoviviparous mhuka, nemhaka yokuti kubereka kunoitika kunze kwomuviri waamai. Kana yangosangana nembeu, hadzi inodzidzorera mukati memuviri wayo.
Platypus: Imhuka inonakidza, maererano nekuti inorondedzerwa semhuka inoyamwisa, asi inokandira mazai, ndicho chikonzero inogonawo kunzi ovoviviparous. Imhando ye semi-aquatic mhuka inogara kumabvazuva kweAustralia neTasmania. Inosiyaniswa nechitarisiko chaicho, ine mhuno yakafanana nemuromo wedhadha, muswe wakafanana nehwebeaver nemakumbo chaiwo seotter. Ine chepfu.
Lution (Crystal Shingles): Inopindirana nemhuka isinganzwisisike, zvichienderana nekuti inotsanangurwa sedzvinyu risina gumbo. Nemamwe mashoko, inoratidzika senyoka. Zvisineyi, zvinozivikanwa kuti idzvinyu maererano nenyaya yekuti makwara kana mavanga eskeleton yaro anowanikwa pamuviri wayo, ine hunhu hwemadzvinyu, zvakare ine nhare yemaziso, zvakasiyana nenyoka.
Imhuka inokambaira inogara muEurope uye inokwanisa kusvika kureba kwemasendimita makumi mana muvarume uye 40 centimita muvakadzi; nguva yavanobereka kazhinji muchirimo, mushure memwedzi mitatu kana mishanu yekuzvitakura. Mhando yehadzi inokandira mazai nemarara akakura mukati, uye kuchechenya kunoitika pakarepo mushure mekuita ikoko.