Mtundu Chordates: kapangidwe ndi chitukuko cha Amphioxus ndi

Development wa Amphioxus ndi udindo wake mwadongosolo kwa nthawi yaitali anakhalabe chinsinsi. Tsopano asayansi mudziwa ndithu kuti izi ndi nthumwi ya mtundu wa Chordates chitukuko zina.

General makhalidwe a mtundu wa Chordates

Nsomba, achule, zokwawa, mbalame, nyama - nyama zonsezi woimira mtundu wa Chordates. Kodi chimagwirizanitsa zamoyo mosiyanasiyananso? Iwo likukhalira kuti iwo onse ndi dongosolo wamba dongosolo.

Pa maziko a thupi ndi mafupa ofananira, wotchedwa poyambira. Mu Amphioxus izo amalimbikira moyo. Pamwamba poyambira ndi chubu ubongo. Pa metamorphosis ambiri a anthu a mtundu izo aumbike msana ndi ubongo. Pansi ofananira mafupa intestine kumaoneka ngati chubu. Khosi la poyambira ndi gill slits. Mitundu zimene zimakhala m'madzi, mbali iyi anapitiriza, pamene dziko khalidwe chabe la chitukuko embryonic.

History of anapeza Amphioxus

Chifukwa Amphioxus chitukuko kwa nthawi yaitali anachititsa kwambiri pa mlanduwo ndi mafunso? mfundo ndi yakuti kwa nthawi yaitali iye ankaona mollusk. Amphioxus (chithunzi m'munsimu chikusonyeza matabwa ake akunja) kwenikweni zikuwoneka ngati nyama. Iye ali ndi zofewa translucent thupi ndipo amakhala ndi m'madzi chilengedwe - mu madzi osaya mwa nyanja ndipo nyanja. Koma makamaka bungwe mkati n'zotheka kudziwa mu mayunitsi osiyana mwadongosolo.

Komanso, kuthokoza kuyesetsa Petra Pallasa ndi Aleksandra Kovalevskogo anapezeka kuti nyama zimenezi makolo a inakhala ano. Asayansi kuitana zamoyo izi mafupawa wamoyo. Akukhulupirira kuti lancelet osati kusanduka, monga mwangwiro ndinazolowera chilengedwe ndi moyo, pakalibe mpikisano.

Features ya kapangidwe kunja

Chifukwa cha mawonekedwe thupi la nyama zimenezi liri ndi dzina zachilendo - lancelet. Photo limasonyeza kuti thupi akufanana wakale chida opaleshoni kuti wakuthwa mbali zonse. Iwo amatchedwa Lancet. kufanana ichi mwangwiro chikusonyeza mbali ya kapangidwe kunja.

Amphioxus thupi kufika kutalika pazipita masentimita 8. Iwo atazunguliridwa mbali nalongosola kumapeto. Pa mbali imodzi ya kotenga khola thupi ndipamene zipsepse - dorsal ndi caudal. Lancelet kumbuyo kumapeto kwa thupi anaikidwa mu mchenga. Kutsogolo ndi preoral Chigwa, atazungulira tentacles.

Mafupa ndi minofu

Development wa Amphioxus yodziwika ndi khama la poyambira pa moyo wake. Mu chingwe cha izo akutambasula pamodzi thupi lonse kuchokera kutsogolo mpaka kumapeto kumbuyo. Pa mbali zonse za poyambira pa imakonzedwa angapo minofu. nyumba imeneyi ya dongosolo locomotor amalola Amphioxus kusuntha uniformly. Minofu contractions kuyambitsa kupinda wa thupi, ndi mwa poyambira ndi rectification ake.

kapangidwe mkati

Amphioxus matupi kupanga machitidwe onse thupi. M'mimba anapereka m'kamwa kutsegula, pakhosi ndipo matumbo kudzera-chubu ndi outgrowth kwa chiwindi, amene amachita ntchito ya prostate. Ndi mtundu wa mphamvu Amphioxus ndi heterotrophic fyuluta feeders. Zimenezi kugwirizana ndi kupuma, yomwe ikuchitika mwa makutu ndipo thupi lonse pamwamba.

Mu M'mimbamo okolozhabernuyu ndi ziwalo lotseguka kusankha. Iwo amakhala ndi machubu ambiri wophatikizidwa - Nephridia. Amphioxus magazi dongosolo unclosed. Amakhala ndi ziwiya ventral ndi dorsal.

Amphioxus Ziwalo zoberekera otchedwa gonads. Izi zopangitsa wophatikizidwa wa kuchulukitsa amene angafikire ku 25. Amphioxus ndi nyama dioecious. Choncho, kukhala mazira kapena testes. ducts maliseche, nyama zimenezi mulibe. Choncho, maselo kulowa M'mimbamo pa yopuma okolozhabernuyu gonads kapena makoma thupi.

Kubereka ndi chitukuko

Ziwalo zoberekera za Amphioxus kupereka umuna awo akunja. Gametes zili mu madzi, pamene iwo coalesce. zazikazi kuikira mazira dzuwa litalowa mu nyengo zonse kupatula yozizira. maselo awo nyongolosi amakhala ndi zinthu zochepa kwambiri dzira yolk ndi yodziwika ndi kukula yaing'ono - 100 microns.

Ngakhale pamaso kuphwanya nkhani dzira Amphioxus kusiyanitsidwa mu atatu zigawo nyongolosi: ecto, meso ndi endoderm. Pa magulu wotsatira omwe ndipamene dongosolo limba ziwalo.

Development wa Amphioxus amapereka lingaliro za maonekedwe a ndondomeko izi mu chordates. Amakhala ndi mndandanda wa njira motsatizana umuna, pogawanikana pamawere, gastro ndi neurulation organogeneza.Razmnozhenie Amphioxus, komanso chitukuko zina n'zogwirizana ndi madzi. Wa dzira mu masiku 4-5 osauka larva. Iwo ali kukula kwa 5mm ndipo amayandama momasuka madzi chifukwa cha cilia ambiri. Mbali larval kumatenga za 3 miyezi. Pa usiku limatuluka pamwamba madzi, ndi limalephera tsiku.

Amfioksidy - wotchedwa chimphona mphutsi za Amphioxus, ndilo chodabwitsa cha nyama dziko. Choyamba, iwo ankalakwitsa akuluakulu. Koma maphunziro ambiri padatsimikiza kuti amakhala yekha pamwamba pa madzi zikuchokera zomera ndi. Amfioksidy kuti angafikire 11 mm, kusunga mbali zonse za nyumba ya larval. thupi lawo ali ndi cilia, pafupifupi chimanga chosakhwima tentacles m'kamwa okolozhabernaya M'mimbamo ndi gonads.

Choncho Amphioxus ali wosazindikira m'madzi chordates. Iwo ali ndi subtype bescherepnyh, kalasi Golovohordovye. Amphioxus yodziwika ndi moyo wongokhala, pokhala nyama dioecious ndi umuna kunja ndi mtundu zotsalira za chitukuko.