Amphioxus - shi ne cewa dabba? Amphioxus: description, tsarin, halaye da kuma siffofin

Amphioxus - dabba alaka da irin Chordates (kungiyar bescherepnyh). Mun bayar da ku don samun matsahi na saba da shi. Muka yi la'akari da tsarin, halaye da kuma siffofin da Amphioxus. Wannan jinsin aka samu a tekuna na temperate da kuma wurare masu zafi da zones. A musamman, Amphioxus rayuwa da kuma a tekun Black Sea.

jiki siffar

Amphioxus jiki siffar m, tapering da wutsiya. A tsawon ne daga 4 zuwa 8 cm. A jikin an rufe tare da guda Layer na epithelium da cuticle secreted da epithelial Kwayoyin. Ƙarƙashin epithelium ne na bakin ciki Layer na connective nama - corium. A dorsal gefen gangar jikin da wutsiya filafilin kifi kaifi tare da fata Musulunci. A jikin aka mĩƙe laterally. tare da ventral gefen guda biyu stretch metaplevralnye folds a haɗa zuwa undernail ɓangare na filafilin kifi Musulunci. Wannan tsarin facilitates karfafawa na jiki matsayi a ruwa kuma qara yanki na lamba tare da shi, wanda yake da muhimmanci a lokacin da motsi ta hanyar jiki twists.

Musculoskeletal tsarin

Dalili na reference frame ne tsirkiya, located tare da jiki daga shugaban to ƙarshen caudal yankin. A tsirkiya, wanda yana da lancelet - wannan samuwar kewaye a cikin connective 'yar jakar, wanda tafiyar matakai form goyon abubuwa filafilin kifi Musulunci da ciwon da tsari chondroid ginshikan. Yana kuma da ke shiga tsakanin mutum da rabo daga cikin musculature (Myomere) ulla miosepty raba su. Myomere rabu mioseptami, dab da tsirkiya a garesu.

muscularity

Striated tsokoki. Raba Myomere da conical siffar, kamar yadda idan retracted cikin juna, tare da su asymmetrical tsari: daura da tsakiyar kowane daga cikinsu a gefen dama ne miosepta a kan hagu da kuma mataimakin versa. Progressive akan rage tsoka kashi ne sashi na jiki masu lankwasa, tãguwar ruwa motsi daga shugaban da wutsiya. Halitta hali na tsoka ƙanƙancewa ne kayyade ta tsakiya m tsarin.

Amphioxus tsirkiya na ƙarshen gaban kara kara fiye da na tsarin jijiya tube, Saboda haka sunan guda aji na subtype - Golovohordovye. Yana da aka hada da babban adadin mai gangara tsoka na faranti kewaye da wani connective nama daina kai hare hare. The mutum faranti rabu cavities, amma a lamba tare da m via gajeren outgrowths.

jijiyoyi

An yi imani da cewa jijiyoyi na dabba rufe. Lalle ne sũ, bãbu gibba jini, amma babu wani real capillaries (thinnest garu tasoshin da monolayer) na kananan jijiyoyi jini shiga intercellular sarari (da suka dace aikin capillaries), ya kuma inganta tattara a kananan jijiyoyinmu.

haihuwa tsarin

Dabe Amphioxus tsarin da aka wakilta jerin guda biyu gonads (gonadal). Suna ayi a ganuwar da atrial kogo. Bescherepnyh (lancelet ciki har da) iri guda ba. A gonads namiji da mace sama-sama ne irin wannan, dabam-dabam ne kawai a girma gametes (oocyte ya fi girma). Balagagge sel haihuwar ta hanyar rata gonads bango fall a cikin atrial rami, inda ruwa ya kwarara dakatar da waje ta hanyar atriopor. Development auku a mai ruwa-ruwa kafofin watsa labarai da kuma halin a cewa akwai wani larval mataki.

A tsarin da larvae

A tsarin da larvae na wani sosai peculiar hanyar: a farkon matakai shi ne halin da wani asymmetrical tsari na bakin (a hagu), da kuma gill slits (a gefen dama), da yawan abin da yake kananan at farko. Kawai daga baya daya jere na gill slits motsa zuwa ciki, sa'an nan zuwa gefen hagu, da kuma bakin da aka gudun hijira zuwa ƙasa. Yawan gill takware karu da breakout ƙarin ramummuka da kuma kafa a tsaye partitions a data kasance mãsu girmansu. Tsutsa rayayye motsa da taimakon cilia rufe jiki, kuma daga baya a kaikaice lankwasawa na jiki, kamar adult siffofin. Ta ayan aiki ciyar a kan kananan planktonic dabbobi. Perioral mazurari da tentacles an kafa ne kawai a karshen larval ci gaba, da tsutsa, kamar girma-up jiki, da miƙa mulki ga rayuwa a kan kasa.

atrial rami

Amphioxus - wata dabba da ciwon atrial kogo. A ta bude rami da kuma gill slits metanefriliev. A nan ya zo da cikakke qwai da maniyyi. Duk wannan na nuna wani connection atrial rami tare da waje muhalli. Anatomically, wannan dangantaka an wakilta wani rami, wanda aka kira atrioporom da kuma bude waje a kan ventral gefe na raya sashi na jiki a gaban dubura. A sarari mahada atriralnoy rami tare da yanayi bayyana a cikin yanayin da samuwar.

Tsutsa Amphioxus jiki a gefe ganuwar da gill takware suna kafa ta a tsaye folds metaplevralnye. Su hankali fadada a kaikaice shugabanci da kuma zuwa ƙasa, sa'an nan Fused tare. A sarari tsakanin folds da kuma wakiltar atrial kogo. A wasu kalmomin, da atrial rami, wanda yana da lancelet - shi ne wani ɓangare na waje yanayi kama metaplevralnymi folds. Yana maida hankali ne akan makogwaro rabo daga hanji, wani babban rabo daga surface na gonads, mamaya m sarari kuma ma wuce dukan, wanda aka adana kawai a cikin nau'i na biyu na cavities tare da babba baki na pharynx, kazalika a endostyle metaplevralnyh folds.

A akanta na atrial rami saboda da yanayin da image Amphioxus zaune. Lokacin binne a ƙasa ruwa kanti na gill slits wuya, kasar gona barbashi iya shigar da gill ramukan da kuma sanƙarar su. Formation na atrial rami, wadda shãmakunta gill takware rabu lamba tare da ƙasa, da kawar da wannan matsala. Ruwa, da karfin zuwa daga atriopora, erodes da ƙasa a cikin wannan yanki, tabbatar da free numfashi da kuma tukar tumbi na na rayuwa kayayyakin. Kamar yadda aka ambata a riga, a Amphioxus larvae, manyan pelagic, atrial rami can. Babu shi, kuma a cikin da dama jinsunan Amphioxididae iyali na manyan pelagic da} uruciyarsa.

Waɗannan su ne babban fasali na Amphioxus - daya daga cikin wakilan chordates.