Kifi

Kifi dabba ce mai ƙusa, mai suna anamniotic, mai ɗauke da ƙwayoyin cuta tare da fuka-fukan rayuwa da gashin kai mai wuya, amma ba shi da gaɓoɓin da ke da lambobi. Ana iya haɗa kifi a cikin Kifi mara wutsiyar phylogenetics)" id="mwGQ" rel="mw:WikiLink" title="Basal (phylogenetics)">asali da kifi mai ƙashi na yau da kullun, wanda ya haɗa da duk kifi mai rai da ƙashi, da kuma placoderms 'Yan Acanthodians. A cikin hutu daga doguwar al'adar haɗa dukkan kifaye a cikin aji ɗaya (Pisces), ilimin zamani na zamani yana kallon kifi a matsayin rukuni na paraphyletic wanda ya haɗa da dukkan dabbobi ban da tetrapods.

Yawancin kifaye suna da jini mai sanyi, zafin jikin su ya bambanta da ruwan da ke kewaye da su, kodayake wasu manyan Masu iyo masu aiki kamar fararen shark da tuna na iya kula da zafin jiki mafi girma. Kifi da yawa na iya sadarwa tare da juna, kamar a lokacin nune-nunen soyayya. Nazarin kifi an san shi da ichthyology .

Akwai fiye da nau'ikan kifi 33,000, sauƙin rukuni mafi girma na vertebrates kuma fiye da duk nau'ikan sauran nau'ikan gargajiya, wato amphibians, dabbobi masu rarrafe, tsuntsaye, da dabbobi masu shayarwa, hade. Yawancin kifi suna cikin aji Actinopterygii, kifin ray-finned, wanda ke da kusan rabin dukkan rayayyun dabbobi.

Kifi na farko ya bayyana a lokacin Cambrian a matsayin ƙananan masu ciyar da matattarar; sun ci gaba da canzawa ta hanyar Paleozoic, suna rarraba cikin siffofi da yawa. Kifi na farko tare da gills na numfashi da ƙuƙwalwar ƙuƙwalwa, ostracoderms, suna da faranti na ƙasusuwa masu nauyi waɗanda suka yi aiki a matsayin ƙwayoyin kariya daga masu cin nama. Kifi na farko tare da jaw, placoderms, ya bayyana a cikin Silurian kuma ya bambanta sosai a lokacin Devonian, "Age of Fishes".

Kifi mai ƙashi, wanda aka rarrabe ta wurin kasancewar ƙwayoyin ruwa da kuma ƙwayoyin cuta daga baya, sun fito ne a matsayin babban rukuni na kifi bayanƘarshen Devonian ya shafe Masu cin nama, placoderms. Ana ci gaba da raba kifi na kasusuwa zuwa kifi na lobe-finned da ray-finned. Kimanin kashi 96% na dukkan nau'ikan kifi masu rai a yau sune teleosts- Ƙungiya kambi na kifi mai fuka-fuki wanda zai iya fitowa daga jawansu. tetrapods, mafi yawan ƙwayoyin ƙwayoyin cuta na ƙasa waɗanda suka mamaye matakan trophic a cikin yanayin ruwa da na ƙasa tun daga Late Paleozoic, sun samo asali ne daga kifi mai laushi a lokacin Carboniferous, suna haɓaka huhu mai numfashi daidai da na ruwa. 

Kifi ya kasance muhimmiyar albarkatun halitta ga mutane tun zamanin da ba a san su ba, musamman a matsayin abinci. Masu kamun kifi na Kasuwanci da na rayuwa gona girbe kifi a cikin kamun kifin daji ko noma su a cikin tafkuna ko gidaje masu kiwo a cikin teku. Ana kama kifi don nishaɗi ko kuma Masu kifi suna kiwon su a matsayin kayan ado don nune-nunen masu zaman kansu da na jama'a a cikin akwatunan kifaye da tafkunan lambu. Kifi sun taka rawa a Al'adun ɗan adam ta hanyar shekaru, suna aiki a matsayin alloli, alamomin addini, kuma a matsayin batutuwan fasaha, littattafai da fina-finai.

 Tushe 
Kalmar kifi ta samo asali ne daga Proto-Jamusanci, kuma tana da alaƙa da Jamusanci , Latin , da Tsohon Irish , kodayake ainihin tushen ba a sani ba; wasu hukumomi sun sake gina tushen Proto-Indo-Turai , wanda aka tabbatar kawai a cikin Italic, Celtic, da Jamusancin.   

Kodayake sau da yawa ana amfani da su sau da yawa, a cikin ilmin halitta 'Kifi' da 'Kifi' suna da ma'anoni daban-daban. Ana amfani da kifi a matsayin sunan mutum ɗaya, ko kuma a matsayin jam'i don bayyana mutane da yawa daga jinsin guda ɗaya. Ana amfani da kifi don bayyana nau'o'i daban-daban ko nau'o-nau'in.

Kimanin shekaru miliyan 530 da suka gabata a lokacin Cambrian_explosion" id="mwrg" rel="mw:WikiLink" title="Cambrian explosion">Fashewar Cambrian, dabbobi masu kama da kifi tare da notochord da idanu a gaban jiki, kamar Haikouichthys, sun bayyana a cikin tarihin burbushin. A lokacin marigayi Cambrian, wasu siffofin da ba su da jaw kamar conodonts sun bayyana.
Rukuni:Kifi