I-sterlet yomndeni wama-sturgeon ithathwa njengenye yezinhlobo zasendulo kakhulu zezinhlanzi: okhokho bayo bavela eMhlabeni ekupheleni kwesikhathi se-Silurian. Ngezindlela eziningi ifana nezinhlobo zayo ezihlobene nayo, njenge-beluga, i-stellate sturgeon, ameva ne-sturgeon, kepha incane ngosayizi. Le nhlanzi sekuyisikhathi eside ibhekwa njengezinhlobo zezentengiselwano ezibalulekile, kepha kuze kube manje, ngenxa yokwehla kwesibalo sayo, ukudotshwa kwe-sterlet endaweni yayo yemvelo akuvunyelwe futhi kubhekwa njengokungekho emthethweni.
Incazelo ye-sterlet
USterlet uyilungu le-cartilaginous fish subclass, ebizwa nangokuthi i-cartilaginous ganoids... Njengawo wonke ama-sturgeon, izikali zale nhlanzi ezidla amanzi angenasawoti zakha ukufana kwamacwecwe amathambo amboza umzimba omise okokuphotha.
Ukubukeka
I-sterlet ibhekwa njengencane kunazo zonke izinhlobo zama-sturgeon. Ubukhulu bomzimba womuntu omdala abuvamile ukudlula u-120-130 cm, kepha imvamisa le-cartilaginous incane kakhulu: 30-40 cm, futhi ayinesisindo esingeqile kwamakhilogremu amabili.
I-sterlet inomzimba ovulekile futhi inkulu ngokuqhathaniswa nayo, inekhanda elingunxantathu eliyisiyingi. Impumulo yayo inde, iyindilinga, nodebe lwangezansi luhlukaniswe kabili, okungesinye sezici ezigqame kakhulu kule nhlanzi. Ngezansi, empumulweni, kukhona umugqa wezimpondo ezinezinsephe, nazo ezikhona kwabanye abamele umndeni we-sturgeon.
Kuyathakazelisa! I-Sterlet ifika ngezindlela ezimbili: i-nosed ebukhali, ebhekwa njengeyakudala futhi enempumulo ebuthuntu, lapho umphetho wesifonyo ugoqiwe ngakhona.
Ikhanda lalo limbozwe ngenhla ngemikhono ethambile yamathambo. Emzimbeni kunama-ganoid esikalini anezimbungulu eziningi, kushintshaniswa nokuqagela okuncane okufana nekama ngohlobo lwezinhlamvu. Ngokungafani nezinhlobo eziningi zezinhlanzi, ku-sterlet i-dorsal fin iyasuswa eduze nengxenye yomsila womzimba. Umsila unesimo esijwayelekile sezinhlanzi ze-sturgeon, kanti i-lobe yayo ephezulu ubude bude kunaleyo engezansi.
Umbala womzimba we-sterlet uvame ukuba mnyama impela, imvamisa iba nsundu ngokumpunga, uvame ukuhlanganiswa nombala ophuzi ophuzi. Isisu sikhanya ukwedlula umbala omkhulu; kwezinye izinhlobo singacishe sibe mhlophe. Ihlukile kunenye i-sturgeon sterlet, okokuqala, ngophiko lwayo lwangaphansi oluphazamisekile nenombolo enkulu yamabhungane, inani eliphelele elingadlula izingcezu ezingama-50.
Uhlamvu nendlela yokuphila
I-Sterlet iyinhlanzi edla ezinye ehlala kuphela emifuleni, futhi ikhetha ukuhlala emadamini ahlanzekile ngokwanele ngamanzi agobhozayo. Ngezikhathi ezithile kuphela lapho lungabhukuda olwandle, kepha lapho lungatholakala kuphela eduze kwemilomo yemifula.
Ehlobo, lihlala emanzini angajulile, kanti i-sterlet esencane nayo ingatholakala emizileni emincane noma ematheku aseduze kwemilambo. Ngekwindla, inhlanzi icwila phansi futhi ilele ezindaweni ezinemigodi ezibizwa ngokuthi yimigodi, lapho ifukamela khona ubusika. Ngenkathi ebandayo, uhola impilo yokuhlala phansi: akazingeli futhi akadli lutho. Ngemuva kokuvuleka kweqhwa, i-sterlet ishiya imigodi ezansi echibini bese inyuka ngomfula ukuze iqhubeke nomjaho wayo.
Kuyathakazelisa! Ngokungafani nama-sturgeon amaningi, athathwa njengabathandi bodwa, i-sterlet incamela ukuhlala emihlambini emikhulu. Ngisho nasemigodini yobusika, le nhlanzi ayihambi yodwa, kodwa inenkampani yezihlobo zayo eziningi.
Amakhulu ama-sterlets kwesinye isikhathi asebusika kwesinye isikhathi sokudangala. Ngasikhathi sinye, zingacindezelwa kakhulu ukuze zingahambisi izigaxa zazo namaphiko.
Ihlala isikhathi esingakanani i-sterlet?
I-sterlet ihlala, njengazo zonke ezinye izinhlanzi ze-sturgeon, isikhathi eside. Impilo yayo ezimweni zemvelo ingafinyelela eminyakeni engamashumi amathathu. Noma kunjalo, uma kuqhathaniswa ne-lake sturgeon efanayo, iminyaka ifinyelela eminyakeni engama-80 futhi nangaphezulu, kungaba okungalungile ukumbiza ngesibindi eside phakathi kwabamele umndeni wakhe.
I-dimorphism yezocansi
I-dimorphism yezocansi kule nhlanzi ayikho ngokuphelele. Abesilisa nabesifazane balezi zinhlobo abahlukile komunye nomunye kungaba ngombala womzimba noma ngosayizi. Umzimba wabesifazane, njengomzimba wabesilisa, umbozwe izikali eziminyene ze-ganoid ezifana namathambo; ngaphezu kwalokho, inani lesikali alihlukile kakhulu kubantu bobulili obuhlukile.
Indawo yokuhlala
USterlet uhlala emifuleni egelezela olwandle olumnyama, i-Azov neCaspian... Kutholakala nasemifuleni esenyakatho, ngokwesibonelo, e-Ob, Yenisei, eNyakatho Dvina, nasemachibini amachibi eLadoga nase-Onega. Ngaphezu kwalokho, le nhlanzi ibigcwaliswe ngokungeyena emifuleni efana neNeman, Pechora, Amur ne-Oka nakwezinye izindawo ezinkulu zokugcina amanzi.
I-Sterlet ingahlala kuphela emadamini anamanzi ahlanzekile agijima, ngenkathi ikhetha ukuhlala emifuleni enenhlabathi eyisihlabathi noma yamatshe amatshe. Ngasikhathi sinye, abesifazane bazama ukuhlala eduze naphansi kwedamu, kuyilapho abesilisa bebhukuda kukholamu lamanzi futhi, ngokujwayelekile, baphila impilo esebenzayo.
Ukudla kweSterlet
I-sterlet yisilwane esidla kakhulu kuma-invertebrate amancane asemanzini. Ukudla kwale nhlanzi kusekelwe ezintweni eziphilayo ze-benthic, ezinjengezibungu zezinambuzane, kanye nama-amphipod crustaceans, onobuhle abahlukahlukene kanye nezikelemu ezinamabhishi amancane ezihlala ezansi echibini. I-sterlet ngeke yenqabe kusuka ku-caviar yezinye izinhlanzi, iyidla ngokuzithandela ikakhulukazi. Abantu abakhulu balolu hlobo bangaphinde badle izinhlanzi ezisezingeni eliphakathi nendawo, kepha ngasikhathi sinye bazama ukuphuthelwa inyamazane enkulu kakhulu.
Kuyathakazelisa! Ngenxa yokuthi ama-sterlet females ahola indlela yokuphila esondele ezansi, futhi abesilisa babhukuda emanzini avulekile, izinhlanzi zabobulili obuhlukile zidla ngokuhlukile. Abesifazane babheka ukudla ezansi, kanti abesilisa bazingela izinambuzane ezingenamgogodla kukholamu lamanzi. Ama-Sterlets akhetha ukuzingela ebumnyameni.
Izinhlanzi ezithosiwe nezincane zondla nge-plankton yezilwane kanye nama-microorganisms, zikhulisa kancane kancane ukudla kwazo ngokungeza kukho kuqala ama-invertebrate amancane futhi amakhulu.
Ukuzala nenzalo
Ngokokuqala ngqa, i-sterlet izalela kusenesikhathi ama-sturgeon: abesilisa abaneminyaka engama-4-5 ubudala, nabesifazane abaneminyaka engu-7-8 ubudala. Ngasikhathi sinye, iyaphinda futhi eminyakeni eyi-1-2 ngemuva kokuzala ngaphambili.
Lesi sikhathi sesikhathi siyadingeka ukuthi owesifazane alulame ngokuphelele "ekuzalweni" kwangaphambilini, okuqeda kakhulu umzimba wabamele lo mndeni.
Isikhathi sokuzalisa le nhlanzi siqala ngasekupheleni kwentwasahlobo noma ekuqaleni kwehlobo - cishe, kusukela maphakathi noMeyi kuze kube sekupheleni kwaso, lapho izinga lokushisa lamanzi echibini lifinyelela kusuka kuma-degree ayi-7 kuye kwangama-20, kanti izinga lokushisa elifanele lale nhlobo yokuzala liyi-10 -15 degrees. Kepha kwesinye isikhathi ukuzala kungaqala ngaphambi noma ngemuva kwalesi sikhathi: ekuqaleni kukaMeyi noma maphakathi noJuni. Lokhu kungenxa yokuthi izinga lokushisa kwamanzi elidingekayo ekuzaleni alibekiwe nganoma iyiphi indlela ngasizathu simbe. Futhi, lapho kufanele kuqale ukuzala kwe-sterlet, izinga lamanzi emfuleni lapho lihlala khona liyathinta futhi.
I-sturgeon ehlala eVolga ayizali ngasikhathi sinye... Abantu abahlala enhla nomfula bazala ngaphambi kwesikhathi kunalabo abathanda ukuhlala ezindaweni ezisezansi. Lokhu kungenxa yokuthi isikhathi sokuzala kwalezi zinhlanzi siwela kuzamcolo omkhulu kunayo yonke, futhi siqala ezindaweni ezingenhla zomfula ngaphambi kwezindawo eziphansi. I-Sterlet izala i-caviar kuma-rapids, kulezo zindawo lapho amanzi acace khona kakhulu, futhi ngezansi kugcwele amatshe amatshe. Uyinhlanzi ezuzwayo ngokwanele: inani lamaqanda abekwe insikazi ngasikhathi sinye lingafinyelela ku-16,000 noma ngaphezulu.
Amaqanda anamathelayo, abekwe ezansi, akhula izinsuku ezimbalwa, emva kwalokho athosa kuwo. Ngosuku lweshumi lokuphila, lapho i-yolk sac yabo inyamalala, ubukhulu bama-sterlets amancane abudluli ku-1.5 cm.Ukuvela kwezinsizwa kulolu hlobo lwezinhlobo ezithile kuhlukile kunokwabantu asebevele bekhulile. Umlomo wezibungu mncane, uhlukanisiwe, kanti izimpondo ezinamaquza zilingana ngosayizi. Indebe yabo engezansi isivele ihlukaniswe kabili, njengakuma-sterlets amadala. Ingxenye engenhla yekhanda ezinhlanzini ezisencane zalolu hlobo imbozwe imiqolo emincane. Ama-juveniles anombala omnyama kunama-congener abo amadala; ukumnyama kubonakala ikakhulukazi engxenyeni yomsila womzimba wezinsizwa zonyaka.
Isikhathi eside, ama-sterlets amancane ahlala endaweni lapho ake avela khona emaqandeni. Futhi kuphela ekwindla, sebefinyelele usayizi ka-11-25 cm, baya emfuleni i-delta. Ngasikhathi sinye, izinhlamvu zobulili obuhlukile zikhula ngejubane elifanayo: bobabili abesilisa nabesifazane kusukela ekuqaleni abahlukile ngosayizi, njengoba, nokho, befana ngombala wabo.
Kuyathakazelisa! I-Sterlet ingazalelana nezinye izinhlanzi zomndeni wama-sturgeon, njengezinhlobo ezahlukahlukene ze-sturgeon, ngokwesibonelo, i-Siberia ne-Russian sturgeon noma i-stellate sturgeon. Futhi kusukela ku-beluga ne-sterlet ngawo-1950s wekhulu lamashumi amabili, i-hybrid entsha yaqanjwa ngokufakelwa - i-bester, okumanje iyinhlobo yezentengiselwano ebalulekile.
Inani lalezi zinhlobo ze-hybrid kungenxa yokuthi, njenge-beluga, ikhula kahle futhi ngokushesha futhi izuze isisindo. Kepha ngasikhathi sinye, ngokungafani nama-belugas akhula sekwedlule isikhathi, ama-besters, njengama-sterlets, ahlukaniswa nokuvuthwa kokuqala kocansi, okwenza kube lula ukusheshisa ukukhiqizwa kwalezi zinhlanzi ekuthunjweni.
Izitha zemvelo
Ngenxa yokuthi i-sterlet ihlala kukholamu yamanzi noma ngisho nangaphansi kwemizimba yamanzi, lezi zinhlanzi zinezitha ezimbalwa zemvelo.
Ngaphezu kwalokho, ingozi enkulu akuyona eyabantu abadala, kodwa amaqanda ama-sterlet kanye nefry, okudliwa yizinhlanzi zezinye izinhlobo, kufaka phakathi lezo ezomndeni wama-sturgeon ahlala lapho kuzalwa khona i-sterlet. Ngasikhathi sinye, i-catfish ne-beluga zimelela ingozi enkulu kunazo zonke ezinganeni.
Inani labantu kanye nesimo sezinhlobo
Ngaphambi, noma eminyakeni engamashumi ayisikhombisa edlule, i-sterlet yayingenye yezinhlobo eziningi kakhulu futhi eziphumelelayo, kepha manje ukungcoliswa kwamachibi okuthuthwa kwendle, kanye nokuzingela ngokweqile sekuwenzile umsebenzi wawo. Ngakho-ke, okwesikhashana manje, le nhlanzi ibhalwe kuRed Book njengengcuphe, futhi ngokokuhlukaniswa komhlaba kwezinhlobo ezivikelwe, izonikezwa isikhundla "sezinhlobo ezisengozini".
Inani lokuhweba
Emuva maphakathi nekhulu lama-20, i-sterlet yayibhekwa njengezinhlanzi ezivame kakhulu kwezentengiselwano, okudoba kwazo kwakwenziwa ngenkuthalo, yize kwakungeke kuqhathaniswe nesilinganiso sangaphambi kokuguqula ukubamba, lapho cishe amathani angama-40 aso abanjwa ngonyaka. Kodwa-ke, okwamanje, ukuthunjwa kwe-sterlet endaweni yabo yemvelo akuvunyelwe futhi akwenziwa nhlobo. Noma kunjalo, le nhlanzi iyaqhubeka nokuvela emakethe, kokubili okusha noma okubandayo, kanye nokudla okunosawoti, okubhemayo nokheniwe. Ivelaphi i-sterlet engaka, uma ukuyibamba emifuleni bekuvunyelwe isikhathi eside futhi kubhekwa njengokungemthetho?
Kuzothakazelisa futhi:
- Pike
- Kaluga
- I-Sturgeon
- Uhlobo lwenhlanzi
Iqiniso ngukuthi abantu abakhathalelayo abenza imisebenzi yokongiwa kwemvelo, abangafuni ukuthi i-sterlet inyamalale ebusweni boMhlaba njengenhlobo yezilwane, sekuyisikhathi esithile baqala ukuzala ngenkuthalo le nhlanzi ekuthunjweni, emapulazini ezinhlanzi akhelwe lezi zinhloso. Futhi, uma ekuqaleni lezi zinyathelo zathathwa kuphela ngenhloso yokonga i-sterlet njengohlobo oluthile, manje, lapho seziyanele izinhlanzi ezizalelwe ekuthunjweni, ukuvuselelwa kancane kancane kwamasiko asendulo okupheka ahlobene nale nhlanzi sekuqalile. Vele, njengamanje, inyama eyi-sterlet ayinakushibhile, futhi ikhwalithi yezinhlanzi ezikhuliselwe ekuthunjweni ingaphansi kwaleyo ekhuliswe ezimweni zemvelo. Noma kunjalo, amapulazi ezinhlanzi ayithuba elihle lokuthi i-sterlet ingagcini nje ngokuphila njengenhlobo, kepha futhi iphinde ibe uhlobo olujwayelekile lokuhweba futhi, njengoba kwenzeka emashumini ambalwa edlule.
Kuyathakazelisa! I-sterlet, ebhekwa njengencane kunazo zonke izinhlobo ze-sturgeon, yehlukile kwabanye abamele lo mndeni hhayi ngosayizi wayo omncane kuphela, kepha nokuthi ifinyelela ekuvuthweni ngokocansi ngokushesha kunenye i-sturgeon.
Yilokhu, kanye neqiniso lokuthi i-sterlet iyinhlanzi engathobekile ekudleni, futhi ikwenza kube lula ukuzalanisa ekuthunjweni nasekuzaliseni izinhlobo ezintsha zezinhlanzi ze-sturgeon, njenge-bester. Ngakho-ke, yize okwamanje kungokwesilwane esisengozini yokuqothulwa, i-sterlet isenamathuba amahle okusinda njengenhlobo. Ngemuva kwakho konke, abantu abanasithakazelo kule nhlanzi eyanyamalala ebusweni bomhlaba, ngakho-ke kuthathwa zonke izindlela ezikhona zemvelo ukusindisa i-sterlet.
