Type Chordates: marongerwo uye kusimudzira Amphioxus

Development pamusoro Amphioxus yaro enderana nzvimbo kwenguva refu nguva yakaramba isingazivikanwi. Zvino masayendisiti muzive zvirokwazvo kuti ichi ndicho mumiririri mhando Chordates kunanga kukura.

General zvechadenga mhando Chordates

Fish, amphibians, nezvinokambaira, neshiri, mhuka - mhuka dzose idzi mumiririri norudzi Chordates. Chii dzinobatanidza zvinenge zvakasiyana zvakadai? Zvakaratidza kuti vose vane zvakafanana urongwa mamiriro.

At chinoumba muviri ari axial marangwanda, iyo inonzi Chord. In Amphioxus izvozvo zvikaramba hwose. Pamusoro Chord ndiye Neural chubhu. Panguva metamorphosis ruzhinji vamiririri mhando riri kuumbwa musana uye pfungwa. Under axial marangwanda ura ari kuumbwa sezvo kumicheto. Mitsipa Chord vari Gill slits. In mhando kuti kurarama mumvura, izvi hazvisati zvave kuramba, apo nyika maitire chete embryo kukura.

History yakawanikwa Amphioxus

Sei Amphioxus budiriro kwenguva refu nguva hwakonzera gakava uye mibvunzo? Chokwadi ndechokuti kwenguva refu aionekwa mollusk. Amphioxus (photos pazasi inoratidza nechivako wayo kwokunze) anenge semhuka izvi. Ane nyoro translucent muviri uye anogara ari hwemvura kwezvakatipoteredza - mumvura isina kudzika yamakungwa uye nyanza. Asi kunyanya dzomunyika sangano Zvinobvira kuziva kwavari ari oga enderana dzakabatana.

Uyezve, nemhaka nokuedza Petra Pallasa uye Aleksandra Kovalevskogo kuwanikwa kuti mhuka idzi madzitateguru vertebrates ano. Masayendisiti mudane zvinenge izvi zvipenyu zvisaririra. Zvinofungidzirwa kuti lancelet asina kumhuka, sezvo zvakakwana dzakashandisa mamiriro ezvinhu uye nzira youpenyu tisina vakwikwidzi.

Mamiriro Akaita wokunze mamiriro

Nokuda muviri chimiro mhuka iyi ine kujairika zita - lancelet. Photo inoratidza kuti muviri afanane chekare kuvhiya Chishandiso kuti wakarodzwa kumativi ose. Zvakanyorwa kunzi Lancet. Kufanana ichi zvakakwana inoratidza zviri kwokunze mamiriro.

Amphioxus muviri rinosvika vaifanira kureba 8 cm. It uchidzvinyirirwa mativi uye akataura pakuguma. Kune rimwe divi longitudinal nedanga muviri rinoumbwa zvimbi - dorsal uye caudal. Lancelet shure kuguma muviri akavigwa jecha. Pamberi riri preoral mwena, takapoteredzwa tentacles.

Marangwanda uye tsandanyama

Kugadzirwa Amphioxus inozivikanwa nokuda kupfuurira pamusoro Chord muupenyu hwake hwose. Mune beach kwayo kunosvika achitevedza muviri wose kubva mberi kusvika shure kumagumo. On mativi ose Chord zvakarongwa pamusoro dzinoverengeka netsandanyama. maumbirwo ichi locomotor hurongwa anobvumira Amphioxus kufamba noruvara. Muscle sunga kukonzera vachikotama womuviri, uye achishandisa Chord iri kwayo rectification.

zvemukati mamiriro

Amphioxus miviri vanoumba zvose vasiri gadziriro. Zvomudumbu nechipiriso zvokuudzwa richizarurwa huro uye ura kuburikidza-chubhu pamwe hepatic outgrowth, izvo anoita mashandiro kweprostate gland. By mhando simba Amphioxus vari heterotrophic firita vanongodya. Izvi kune chokuita kufema, iro rinoitwa kuburikidza gills uye muviri wose pamusoro.

In okolozhabernuyu mhango uye nhengo rakavhurika vakasarudzwa. Vari anomiririrwa aiwanzopiwa wokushanda sepombi dzakawanda - Nephridia. Amphioxus kweropa maitiro unclosed. Inoitwa ventral uye dorsal midziyo.

Amphioxus nhengo dzokubereka nadzo anonzi gonads. Izvi aiwanzopiwa wokushanda mumasero ane uwandu zvinogona kusvika kusvika 25. Amphioxus imhuka dioecious. Naizvozvo, vanova ovaries kana testes. Dzokubereka ducts, mhuka idzi havana. Naizvozvo, masero kupinda mhango panguva yokuzorora okolozhabernuyu gonads kana masvingo muviri.

Kubereka uye kubudirira

Nhengo dzokubereka nadzo kuti Amphioxus zvinopa muchangosangana kwavo kwokunze. Gametes dziri mumvura, apo ivo coalesce. Nhunzvi mazai avo ranyura nenguva zvose kunze chando. Dzavo utachiona masero ane dukuduku zai mondo uye inozivikanwa duku saizi - anenge 100 microns.

Kunyange asati kurwadziswa zai mukati Amphioxus kusiyaniswa nhatu utachiona akaturikidzana: ecto, meso uye endoderm. Panguva mapoka Zvakazoitwa chimwe nechimwe anoumba munhu dzakasiyana nhego hurongwa.

Kugadzirwa Amphioxus anopa imwe pfungwa pamusoro zviri kwacho izvi chordates. Inoitwa akatevedzana anotevedzana dzinotsanagura fertilization, cleavage, gastro uye neurulation organogeneza.Razmnozhenie Amphioxus, uyewo avo pakuzadzisa vari chokuita zvikuru mvura. Of zai mumazuva 4-5 kusimukira dukutu. It ane saizi kuti 5mm uye floats pachena mumvura nokuda zvakawanda cilia. The larval Danho rinovapo inenge 3 months. Usiku unomutswa mvura pamusoro, uye masikati rinosakara.

Amfioksidy - atumidzwa hofori mazana pamusoro Amphioxus, unova Chiitiko hwemhuka nyika. Chokutanga, vakanga vakarasika kuti vakuru. Asi ongororo dzakawanda kwakati kwatemwa kuti vanorarama chete pamusoro pemvura nemvura Kuronga plankton. Amfioksidy anogona kusvika 11 neMM, vane zvose zvaidiwa larval hurongwa. muviri wavo wakafukidzwa cilia raishanda undeveloped nemumuromo tentacles okolozhabernaya mhango uye gonads.

Saka Amphioxus vari chinyakare zvomumvura chordates. Vanopinda subtype bescherepnyh, kirasi Golovohordovye. Amphioxus dzinoratidzwa ndakagara mararamiro, kuva nemhuka dioecious pamwe zvokunze muchangosangana uye kunanga mhando kukura.