Sharks sune manyan masu farautar ruwa, amma ba don wannan dalili ba, sun keɓe daga mummunan barazanar da ɗan adam ke gabatarwa koyaushe kan yawan jama'a. Raguwar sharks na iya haifar da canje-canje a jikin jikin kifin wanda ya dace a cikin juyin halitta.
Yaya kifin zai kasance ba tare da kasancewar kifayen kifaye ba?
Karbar kifi
Kifi na haɓaka sassan jiki don daidaitawa zuwa yanayi a duk lokacin halittar halittu. Misali, suna haɓaka manyan idanu don gani da kyau, ƙuraje don yin iyo da sauri da gudu daga masu farauta har ma da ƙwayoyin mucous don kare kansu daga dafin wasu algae kamar su anemones.
Idan shark, menene shine babban mai cin tekun, yana fara ragewa da rage yawansu saboda aikin dan adam, kifi ba zai bukaci irin wadannan gabobin na zamani don kubuta daga garesu ba, don haka ilimin kifi na iya canzawa tsawon karnoni.
Misali, wasu nau'ikan kifayen na iya dakatar da bunkasa irin wadannan manyan idanun ko kuma su kirkiro kananan wutsiyoyi, saboda bukatar su ta ninkaya da sauri.
Zanga-zangar sakamakon bincike ne kan nau'ikan kifaye daban-daban a cikin Rowley Shoals da Scott Reefs, tsarin murjani biyu masu makwabtaka da juna a arewa maso yammacin Ostiraliya, wanda ya yanke shawarar cewa waɗannan canje-canjen na iya shafar yanayin halittu.
"Bambancin kamannin jikin kifin wanda ke rayuwa a cikin sassan murjani guda biyu na iya haifar da sakamako game da kwararar kuzari a cikin tsarin halittu da kyakkyawan tasiri akan gidan yanar gizo na abinci”In ji shugaban aikin, Shanta Barley, na Jami’ar Western Australia (UWA).
Babban bambancin da aka kafa tsakanin gwanayen murjani biyu da aka karanta shine ba'a yarda da kamun kifi a Rowley Shoals ba kuma a Scott Reefs haka ne, idan dai kasuwanci ne. Masun kifin Shark a cikin wannan mashigin mai murjani na sama da ƙarni ɗaya kuma, sakamakon haka, yawan kifin kifin shark yana raguwa.
Tasiri kan sharks
Bayan shekarun da suka gabata, kamun kifin na kifin shark ya karu musamman a yankin. Hakanan buƙatar buƙatun ƙira a cikin kasuwar Asiya. Wannan, kamar yadda zaku iya tsammani, Yana haifar da mummunar lalacewa ga yawan kifin shark a kan Scott Reefs.
Masu binciken sun tattara kifayen 611 na nau'ikan halittu guda bakwai a duka wuraren kuma sun dauki hoto. Don lura da bambance-bambancen halittar kowane kifin, ana yin hotunan ne ta hanyar zamani don ganin fadi da tsawon jikin kowane kifin, yankin idanuwa da jela.
Canjin halittu
Bayan sakamakon nazarin hotunan halittar halittar kifin da ke cikin kifaye biyu, an gano cewa a cikin Scott Reefs idanun kifin da galibi ke kama shark. suna da ƙarancin kaso 46% cikin nau'ikan nau'ikan waɗanda ke zaune a Rowley Shoals.
An samo irin wannan sakamakon a cikin nazarin gwargwadon wutsiya, tunda yakai 40% karami. Wannan na iya kasancewa saboda kifin baya buƙatar irin waɗannan manyan wutsiyoyi ko idanu don gani da gudu daga sharks, saboda yawan su yana taɓarɓarewa.
"Idanuwa suna da matukar muhimmanci wajen gano masu farauta, musamman a yanayin rashin haske, lokacin da sharks ke farautar abin da suke farauta, kuma yanayin wutsiya yana ba su damar kara gudu da tserewa daga sharks," in ji Hammerschlag, marubucin binciken binciken.
Kamar yadda kuke gani, dan adam yana haifar da sauye-sauye a tsarin halittar kifin, tunda ayyukan sa na tsinkaye da bijirewa masu farautar sa. sun daina zama masu larura. Ananan kaɗan, a tsawon shekaru, ilimin halittar waɗannan kifayen na iya zama ya banbanta da juna a kan wani murfin murjani dayan, duk da cewa sun kasance iri ɗaya ne.