{"id":25552,"date":"2014-05-01T15:50:23","date_gmt":"2014-05-01T12:50:23","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=25552"},"modified":"2018-09-21T22:56:29","modified_gmt":"2018-09-21T19:56:29","slug":"kor-magara-baligi-su-emerek-goruyor","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2014\/05\/01\/kor-magara-baligi-su-emerek-goruyor","title":{"rendered":"K\u00f6r ma\u011fara bal\u0131\u011f\u0131 su emerek g\u00f6r\u00fcyor"},"content":{"rendered":"

Meksika k\u00f6r ma\u011fara bal\u0131\u011f\u0131 (Astyanax mexicanus<\/em>) g\u00f6zleri olmayan bir canl\u0131 olarak \u015fa\u015f\u0131rt\u0131c\u0131 bi\u00e7imde a\u00e7\u0131kg\u00f6z. Evi olarak g\u00f6rd\u00fc\u011f\u00fc zifiri karanl\u0131k ma\u011faralarda kaya gibi engellere toslamadan g\u00fcvenli bir bi\u00e7imde hareket edebilmesinin s\u0131rr\u0131 nihayet \u00e7\u00f6z\u00fcld\u00fc. Ma\u011fara bal\u0131\u011f\u0131n\u0131n numaras\u0131, suyu emerek a\u011fz\u0131na doldurmak, bu suyla \u00e7evresinde dalgalar olu\u015fturmak ve dalgalar\u0131 duvar gibi b\u00fcy\u00fck nesnelerden sektirmek. Ma\u011fara bal\u0131\u011f\u0131, seken suyun hareketlerini yan kanatlar\u0131 ile tespit edebiliyor. T\u00fcm bal\u0131klar yan kanatlar\u0131 ile bu hareketleri alg\u0131layabilir ve su emebilirler, fakat ma\u011fara bal\u0131\u011f\u0131 bu ikisini birle\u015ftirmi\u015f bilinen ilk canl\u0131.<\/p>\n

Baz\u0131 Astyanax mexicanus<\/em>\u2019lar a\u00e7\u0131k sularda ya\u015fasa da, populasyonlar\u0131n\u0131n pek \u00e7o\u011fu evlerini su dolu ma\u011faralara kurmu\u015ftur. Bin y\u0131l\u0131 a\u015fk\u0131nd\u0131r daimi karanl\u0131kta ya\u015fayan bu bal\u0131klar, g\u00f6zleriyle birlikte deri pigmentlerini de kaybederek soluk beyaz bir renk alm\u0131\u015flard\u0131r.<\/p>\n

\u015eimdiye dek ara\u015ft\u0131rmac\u0131lar bu bal\u0131klar\u0131n, \u00e7evrelerindeki suda meydana gelen bas\u0131n\u00e7 de\u011fi\u015fikliklerini kullanarak y\u00f6n bulduklar\u0131n\u0131 d\u00fc\u015f\u00fcn\u00fcyordu. T\u00fcm bal\u0131klar gibi onlar da yandaki kanatlar\u0131 ile bas\u0131nc\u0131 alg\u0131layabileyecekleri bir kanala sahiplerdi.<\/p>\n

\u0130srail\u2019de Tel Aviv \u00dcniversitesi\u2019nden Roi Holzman liderli\u011findeki bir ekip laboratuvar ortam\u0131nda ma\u011fara bal\u0131klar\u0131n\u0131 yak\u0131ndan inceledi. Holzman, ara\u015ft\u0131rmada bal\u0131klar\u0131n s\u00fcrekli olarak a\u011f\u0131zlar\u0131n\u0131 a\u00e7t\u0131klar\u0131n\u0131 ve a\u011f\u0131zlar\u0131na doldurduklar\u0131 suyu solunga\u00e7lar\u0131na do\u011fru bo\u015faltt\u0131klar\u0131n\u0131 g\u00f6zlemlediklerini s\u00f6yl\u00fcyor. Daha \u00f6nce hi\u00e7bir ara\u015ft\u0131rmac\u0131 suyu emme hareketini fark etmedi\u011fi i\u00e7in Holzman bal\u0131klar\u0131n neden bunu yapt\u0131klar\u0131n\u0131 a\u00e7\u0131klamaya karar verdi.<\/p>\n

\u00d6ncelikle ekip, bal\u0131klar\u0131n su emme s\u0131kl\u0131klar\u0131n\u0131 normal \u00e7evre ko\u015fullar\u0131nda kaydetti. Daha sonra akvaryumdaki nesneler yeniden d\u00fczenlenerek bal\u0131klar\u0131n akl\u0131 kar\u0131\u015ft\u0131r\u0131ld\u0131. Bu halde ma\u011fara bal\u0131klar\u0131 normal ko\u015fullardakinden d\u00f6rt kat daha s\u0131k su emdi ve daha yava\u015f y\u00fczd\u00fc. Kaybolmu\u015f ya da rotalar\u0131n\u0131 yeniden belirlemeye \u00e7al\u0131\u015f\u0131yor gibiydiler. Bal\u0131klar, duvar gibi b\u00fcy\u00fck bir nesneye yakla\u015ft\u0131\u011f\u0131nda da fazla su emmeye ba\u015flad\u0131lar. Nesneye 7 cm uzakl\u0131kta iken normal ko\u015fullarda ger\u00e7ekle\u015fenden iki kat fazla su emdiler. Uzakl\u0131k 2 cm olup giderek azald\u0131\u011f\u0131nda su emme oran\u0131 alt\u0131 kat\u0131na \u00e7\u0131kt\u0131.<\/p>\n

Holzman, \u201cBu hayvan bir bas\u0131n\u00e7 dalgas\u0131 yay\u0131yor ve \u00e7evredeki nesneler taraf\u0131ndan yarat\u0131lan bas\u0131n\u00e7 de\u011fi\u015fimini alg\u0131l\u0131yor\u201d diyor. Sudaki bas\u0131n\u00e7 de\u011fi\u015fimlerini \u00f6l\u00e7en Holzman, suyun emilip b\u0131rak\u0131lmas\u0131yla olu\u015fan sinyalin, sadece bal\u0131\u011f\u0131n hareketi ile olu\u015fandan 60 kat daha g\u00fc\u00e7l\u00fc oldu\u011funu buldu.<\/p>\n

Holzman ayn\u0131 \u015fekilde y\u00f6n bulan ba\u015fka bir bal\u0131k olup olmad\u0131\u011f\u0131n\u0131 hen\u00fcz bilmediklerini, fakat olas\u0131l\u0131\u011f\u0131n y\u00fcksek oldu\u011funu belirtiyor: \u201cMa\u011fara bal\u0131\u011f\u0131 zaten emrinde bulunan ara\u00e7lar\u0131 basit\u00e7e uyarlard\u0131, bu nedenle di\u011fer bal\u0131klar\u0131n da ba\u011f\u0131ms\u0131z olarak bu evrimi ge\u00e7irmi\u015f olmalar\u0131 olas\u0131.\u201d Yarasa ve balina gibi karma\u015f\u0131k y\u00f6n bulma sistemlerine sahip hayvanlardan farkl\u0131 olarak, ma\u011fara bal\u0131\u011f\u0131 al\u0131c\u0131lar\u0131n\u0131 av\u0131n\u0131 bulmak ve yakalamak i\u00e7in kullanm\u0131yor. Holzman bunu sadece y\u00f6n bulmak i\u00e7in kulland\u0131\u011f\u0131n\u0131 s\u00f6yl\u00fcyor, \u00e7\u00fcnk\u00fc \u201cBu bal\u0131klar, yarasa d\u0131\u015fk\u0131s\u0131 yiyor.\u201d<\/p>\n

Kaynaklar<\/strong><\/p>\n

1) Andy Coghlan, \u201cZoologger: The blind fish that sucks it and \u2018sees\u2019\u201d, www.newscientist.com.<\/p>\n","protected":false},"excerpt":{"rendered":"

Meksika k\u00f6r ma\u011fara bal\u0131\u011f\u0131 (Astyanax mexicanus) g\u00f6zleri olmayan bir canl\u0131 olarak \u015fa\u015f\u0131rt\u0131c\u0131 bi\u00e7imde a\u00e7\u0131kg\u00f6z. Evi olarak g\u00f6rd\u00fc\u011f\u00fc zifiri karanl\u0131k ma\u011faralarda kaya gibi engellere toslamadan g\u00fcvenli bir bi\u00e7imde hareket edebilmesinin s\u0131rr\u0131 nihayet \u00e7\u00f6z\u00fcld\u00fc. Ma\u011fara bal\u0131\u011f\u0131n\u0131n numaras\u0131, suyu emerek a\u011fz\u0131na doldurmak, bu suyla \u00e7evresinde dalgalar olu\u015fturmak ve dalgalar\u0131 duvar gibi b\u00fcy\u00fck nesnelerden sektirmek. Ma\u011fara bal\u0131\u011f\u0131, seken suyun […]<\/p>\n","protected":false},"author":448,"featured_media":25553,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[160,21,38],"tags":[1138,2112,3275,595],"class_list":["post-25552","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-123-sayi","category-biyoloji","category-dergi-sayilari","tag-balik","tag-canlilik","tag-kor-magara-baligi","tag-yasam"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t