Ilimin kimiyyar kifi reshe ne na ilimin kimiyyar halittu wanda ya kware kan nazarin rayuwar kifin:
- yawan kuzari;
- rukuni iri daban-daban;
- rudanin rayuwar kifi;
- abinci mai gina jiki, haifuwa da hanyoyin rayuwa;
- dangantakar kifi da sauran wakilan dabbobi da muhalli.
Kifi wani yanki ne na kashin baya da ke rayuwa a jikin ruwa kawai, kodayake akwai kifin huhu wanda zai iya zama a kan ƙasa na ɗan wani lokaci (masu sarrafawa, wuraren hawa hawa, masu tsalle a laka). Sun bazu zuwa duk kusurwowin Duniya, daga zafi mai zafi zuwa sararin samaniya mai sanyi. A cikin teku da tekuna, kifi na iya rayuwa a zurfin sama da mita 1000, saboda haka akwai nau'ikan da har yanzu ilimin kimiyyar zamani bai sansu ba. Hakanan, daga lokaci zuwa lokaci yana yiwuwa a gano jinsunan zamanin da wadanda suka wanzu shekaru miliyan 100 da suka gabata, ko ma sun girme shi. Fiye da nau'ikan nau'in kifi 32.8 dubu ne sananne a duniya, girman su ya bambanta daga 7.9 mm zuwa 20 m.
Masana kimiyya sun rarrabe irin waɗannan rukunin kifaye, ya danganta da halayen mazauninsu:
- pelagic - a cikin shafi na ruwa (sharks, pike, herring, tuna, walleye, trout);
- abyssal - rayuwa a cikin zurfin fiye da 200 m (masu cin baƙi, masu kifi);
- dabbobin ruwa - a yankunan bakin teku (gobies, allurar teku, karnuka masu hadewa, skates);
- gindi - rayuwa a ƙasa (flounders, rays, catfish).
Tasirin tasirin abubuwan ruwa akan rayuwar kifin
Ofaya daga cikin mahimman abubuwa don rayar da kifi shine haske. Haske mai kyau yana basu damar tafiya cikin ruwa. Gwargwadon zurfin kifin yana rayuwa, ƙarancin haske ya shiga wurin, kuma jinsunan da ke rayuwa ƙwarai da gaske ko a ƙasan makafi ne ko kuma suna hango haske mai rauni tare da idanun telescopic.
Tunda yawan zafin jikin kifi ya dogara da yanayin zafin yanayin muhallinsu, saboda haka, ruwan dumi da sanyi yana shafar tsarin rayuwarsu ta hanyoyi daban-daban. A cikin ruwan dumi, aikin kifi, haɓakar su, ciyarwa, haifuwa da ƙaura. Wasu kifaye suna dacewa da zafi sosai har suna rayuwa a maɓuɓɓugan ruwan zafi, yayin da wasu ke iya tsayayya da ƙananan matakan ruwan Antarctica da Arctic.
Ana samun iskar oxygen daga kifi daga ruwa, kuma idan yanayinta ya tabarbare, zai iya haifar da ci gaba a hankali, cuta har ma da mutuwar yawan alumma. Saboda haka haɗari ga kifi wasu gurɓataccen gurɓataccen ruwa ne, musamman malalar mai. Ta hanyar ciyarwa, kifaye masu farauta ne, masu zaman lafiya ne kuma masu komai. Suna da alaƙa tsakanin mutane iri ɗaya da jinsuna daban daban, haka nan tare da wakilan wasu ajin na fauna.
Don haka, kifi sune dabbobin da ke cikin ruwa masu ƙima waɗanda ke zaune a tafkunan ruwa iri daban-daban, ba wai kawai suna rayuwa a cikin koguna, koguna, tekuna, da teku ba, har ma da waɗanda aka kame - a cikin akwatinan ruwa. Suna da manyan bambance-bambance a tsakanin su, kuma ilimin zamani har yanzu yana da abubuwa da yawa don koyo game da su.
