I-Los Skhokho (Ama-Chondrichthyans), abizwa nangokuthi izinhlanzi ezinamathambo, ziyiqembu lezilwane ezinomgogodla zakudala zasemanzini. Nakuba zingebaningi noma zihlukene njengezinhlanzi ezinamathambo, ukuguquguquka kwazo kokuma kwazo, izicubu zezicubu zokubhukuda, izitho zezinzwa, nemikhuba enamandla yokuzingela kanye nemihlathi kubonisa ukuthi zinikezwe isimo esiqinile semvelo endaweni ezihlala kuyo.
Kulesi sihloko sizokutshela konke odinga ukukwazi mayelana Chondrichthyes, izici zabo kanye biology.
Izici eziyinhloko zamaChondrichthyes
Kunezinhlobo ezimbili zezinhlanzi ze-cartilaginous. Okulandelayo, sizochaza izici zayo eziyinhloko:
Elasmobranchs
Oshaka nemisebe kungokwaleli qembu lezilwane. Ezinye zazo ziyizilwane ezidla inyama, zithola inyamazane yazo ngezitho zazo ezinukayo ngenxa yokungakhuli kahle kokubona kwazo. Njengamanje, kunezinhlobo ezingaphezu kuka-400 zoshaka ngama-oda angu-8 kanye nezinhlobo zemisebe ezingaba ngu-500 ngama-oda angu-4. Mayelana noshaka, abaningi banalezi zimpawu ezilandelayo:
- Umzimba: Umzimba omise okwe-spindle onobuso obucijile nesisu ngaphambili. Umsila womzimba unomsila ovaliwe ongavamile, okungukuthi, kunezimo ezimbili ezahlukene kanye nezakhiwo zamaqabunga, enye yazo iqukethe ukuphela komgogodla, kanti ngaphambili inepheya le-pectoral fins, i-pelvic fins. , kanye nomgogodla amabili. amaphiko angajwayelekile. Kwabesilisa, amaphiko e-pelvic ngaphambilini ayeguqulwa njengezitho zocansi zokukhwelana futhi abizwa nge-glycoptera, pteropods, noma uhlobo.
- Umbono, isikhumba kanye nezitho zama-receptor: maqondana nomlomo, banamakhala afanayo, aphuma emlonyeni nangaphambili. Amehlo awanazo izivalo, nakuba ezinye izinhlobo zinezingqimba ezi-nictitating, ezine-stoma ngemuva kwejwabu leso ngalinye. Isikhumba siqinile futhi kwezinye izinhlobo sifana ne-sandpaper, sinezikali ezimise okwepuleti, ezibuye zibizwe ngokuthi ama-dermal scale, ahlelwa ngendlela yokunciphisa ukuxokozela futhi abheke emuva. Anama-neuromas kuyo yonke imizimba yawo nasemakhanda, okungama-receptors azwela kakhulu ekudlidlizeni nasemisinga yamanzi. Futhi banama-receptors akhethekile angakwazi ukubona inyamazane ngokusebenzisa insimu kagesi abayikhiphayo, angama-blister e-Lorenzini ekhanda.
- Amazinyo: Amazinyo awahlangani nomhlathi ongezansi, kunemigqa emibili, umugqa wokugcina uthatha indawo yamazinyo angekho ohlwini lokuqala, ngakho amazinyo amasha angakhula njalo. Ngokuya ngezinhlobo zezilwane, lezi zingaba nesimo se-serrated ukusika ukudla, zibukhali futhi zibe nomsebenzi wokubamba, endabeni yezinhlobo ezinemigqa, zinamazinyo ayisicaba angaklwejwa phezulu.
- Amathambo Nokubhukuda: Anamathambo oqwanga anamaminerali, hhayi amathambo njengezinye izinhlanzi. Futhi, abanaso esinyeni sokubhukuda, okubangela ukuthi bahlale bebhukuda noma bahlale phansi, kungenjalo bazocwila. Ngakolunye uhlangothi, banesibindi esikhulu, esiqukethe i-lipids (squalene), esivimbela futhi ukuba singacwili.
Holocephalos
Ngaphakathi kwamaChondrichthyes sithola leli qembu elihlanganisa ama-chimera. Leli qembu elincane lakhiwe cishe izinhlobo ezingama-47 namuhla. Ngokwe-anatomically inengxube yezinhlamvu zezinhlanzi ze-elasmobranch nezamathambo:
- Umzimba: Zinokwakheka okuxakile, umzimba wazo mude futhi amakhanda azo aphumele ngaphandle, anesakhiwo sakudala esikwazi ukusekela ezinsikazi ngesikhathi sokukhwelana. Ikhala layo linjengonogwaja kanti umsila wayo ufana nesiswebhu.
- Imihlathi namazinyo: Abanawo amazinyo, kodwa kunalokho ububanzi, amapuleti flat. Umhlathi ongenhla uhlanganiswe ngokuphelele nogebhezi, ngokungafani nezinye, yilapho igama lawo livela khona (holo = konke, konke kanye ne-cephalo = ikhanda).
- Usayizi: Zingaba ngamamitha angu-2 ubude.
- ukuzivikela: Iphiko lalo lomhlana linomgogodla onoshevu.
- Ukudla: Ukudla kwazo kusekelwe kuma-crustaceans, ama-mollusk, ama-echinoderm, izinhlanzi ezincane, nolwelwe, okuyingxube yokudla ezigaya lapho zidla.
Ukubhukuda kwe-Chondrichthyes
Ama-Elasmobranch anezikali zesikhumba, eziwavumela ukuba anciphise ukuxokozela lapho ebhukuda. Ngakolunye uhlangothi, kanye nesibindi sazo esicebile nge-lipid, ikhono lazo lokugwinya umoya, namaphiko, zingababhukudi abahle kakhulu futhi lezi zimo zibavumela ukuthi bahlale emanzini. Amaphiko ayinqaba angakwenza ujike, ngisho nezimpiko zingakulawula. Ngakolunye uhlangothi, iphiko elingemuva lingakwazi ukulawula i-thrust futhi likhiqize amandla okumiswa ngenxa yokuma kwalo okungajwayelekile.
Imisebe yeManta ijwayela ukuphila ngaphansi kwamanzi, umzimba uyisicaba, unamaphiko afanayo anwebekayo futhi ahlangane nekhanda, enze njengamaphiko lapho ubhukuda. Amazinyo azo ayisicaba, akwazi ukukhuhla indawo kanye nokugaya ukudla, okuvamise ukuba ama-crustaceans, ama-mollusk nezinhlanzi ezincane.
Imisila yawo imise okwesiswebhu, inomgogodla owodwa noma ngaphezulu ekugcineni, oxhumene nezindlala ezinobuthi zezinhlobo ezithile. Futhi zinezitho zikagesi ezinhlangothini zombili zamakhanda azo, ezingakhiqiza ukushaqeka kukagesi futhi zishaqise inyamazane yazo noma izilwane ezizidlayo.
Ukuzala
Izinhlanzi ze-cartilaginous zinokuvundiswa kwangaphakathi kanye nezindlela zokuzala ezihlukene esizozibona ngezansi:
- I-Oviparous: Babekela amaqanda agcwele isikhupha ngokushesha ngemva kokuvundiswa. Oshaka abaningi kanye nemisebe kuzalela amaqanda ku-keratinous sac. Imicu efana ne-tendril yakha ekugcineni kwesaka, esetshenziselwa ukunamathela entweni eqinile yokuqala abayithintayo. Imibungu ingakheka ezinyangeni eziyisi-6 kuye eminyakeni emi-2. Ngokuvamile leli phethini livela ezinhlotsheni ezincane ze-benthic, ezingabekela amaqanda angaba ngu-100.
- I-Viviparous: Bazoba ne-placenta yangempela lapho umbungu ungadla khona. Le ndlela yokukhiqiza yathuthukisa impumelelo yabo yokuziphendukela kwemvelo kuleli qembu. Kwenzeka cishe ku-60% wezinhlanzi ze-cartilaginous kanye nezinhlobo ezinkulu ezisebenzayo.
- I-Oviviparous: zigcina i-embryo eshubhuni le-fallopian ngesikhathi sokukhula kombungu futhi zidla isaka layo lomthubi kuze kube yilapho lizalwa. Ngokulandelayo, ihlinzeka imibungu ngezinhlobo ezahlukene zokudla, njenge-lecithin, lapho umbungu udla khona isikhuphashi seqanda; umsoco wezicubu, lapho umbungu owodwa noma ngaphezulu ondliwa uketshezi (umsoco wezicubu) okhiqizwa i-villi endaweni engaphakathi yesibeletho. Ngakolunye uhlangothi, kunamaqanda, okungukuthi, imibungu edla amaqanda avundisiwe lapho esesibelethweni. Ekugcineni, kukhona ama-oleander noma amazimuzimu esibelethweni.
Ngithemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana namaChondrichthyes nezici zawo.