Video narration
Kya tumne kabhi socha hai - paani ke neeche ki machhli, upar baithe keede ko kaise giraati hai? Miliye Archerfish se. Yeh munh se paani ki tez dhaar chhodkar keede ko takkar maarti hai, jisse woh paani mein gir jaata hai. Par nishaana itna seedha nahi. Paani ke gilaas mein rakhi chamach kabhi tedhi dikhi? Keede se aati roshni paani mein pahunchkar mudti hai; is mudne ko apavartan kehte hain. Isliye upar baitha keeda paani ke bheetar se dekhne par apni asli jagah se hatkar dikh sakta hai. Yahi pech hai: keeda jahaan dikhta hai, uski asli jagah usse alag ho sakti hai. Archerfish is fark ke hisaab se apna nishaana theek karti hai, phir paani ki dhaar chhodti hai. To haan - Archerfish paani ki dhaar se upar ka keeda giraati hai, aur apavartan se badli dikhti jagah ke mutaabik nishaana saadhti hai.