Izilwane: Okufanele Ukwazi

Izilwane ziwuhlobo oluthile lwesidalwa esiphilayo. Uma zidla, izilwane zimunca izinto kwezinye izinto eziphilayo: inkomo, isibonelo, idla utshani. Lapho kugayeka ukudla, kudonsa ukudla futhi kulungiselele ukudliwa. Lokhu kuvumela amandla ekudleni ukuthi aguqulwe abe amandla noma ukushisa. Izitshalo zona zithola amandla azo ekukhanyeni kwelanga. Bathola kuphela amabhulokhi wokwakha emhlabathini ngezimpande zabo.

Ngaphezu kwalokho, izilwane zidinga umoya-mpilo ukuze ziphefumule. Izinhlanzi zithola umoya-mpilo wazo emanzini nakwezinye izilwane emoyeni. Ngokuvamile, izilwane zingahamba ngaphansi kwamandla azo futhi zithole umhlaba wazo ngamehlo, izindlebe, nezinye izitho zezinzwa. Ezinye izilwane zinengqamuzana elilodwa kuphela, ezinye zinamangqamuzana amaningi.

Ngokombono wesayensi, umuntu futhi uyisilwane. Nokho, ngokuvamile, uma umuntu ekhuluma “ngezilwane” ngokuvamile usho “izilwane ngaphandle kwabantu”.

Ungazihlukanisa kanjani izilwane?

Kunezindlela ezimbalwa ezilula zokuhlukanisa izilwane, isibonelo, ngokwendawo yazo: izilwane zasehlathini, izilwane zasolwandle, njalonjalo. Ukuhlukaniswa kwezilwane zasendle nezilwane ezifuywayo nakho kungenzeka futhi kuwusizo. Nokho, lezi zigaba ngokuvamile azicaci. Inyamazane, isibonelo, iyisilwane sasehlathini kanye nesilwane sasendle. Iminenke ingahlala olwandle, echibini, noma emhlabeni.

Isigaba sokuqala sesayensi sivela ku-Carl von Linné. Waphila eminyakeni engaba ngu-300 edlule. Wanikeza izitshalo, izinhlobo zezilwane, namaminerali amagama esiLatini, okwakungabonakala ngawo ngokucacile izidalwa. Amagama asevele anikeza inkomba yobudlelwano. Isistimu yakhe iye yacwengwa ngokuhamba kwesikhathi.

Isayensi namuhla ikhuluma ngezilwane, umbuso wezitshalo, umbuso wesikhunta, nokunye okuningi. Umbuso wezilwane ubizwa nangokuthi umbuso wezilwane. Ingahlukaniswa ibe yi-Vertebrate phylum, i-Mollusk phylum kanye ne-Arthropod phylum, nokunye okumbalwa. Sazi kakhulu izilwane ezinomgogodla. Sizihlukanisa zibe izigaba zezilwane ezincelisayo, izinyoni, izilwane ezihlala emanzini, ezihuquzelayo nezinhlanzi.