 Hi all, have you ever wondered why puffer fish spawned along the coast at night during spring tide? Now recently it is in news because the scientists have found out the answer for this question. So to know the answer just stay tuned in this video. We have to know two things. We have to know what is spawning and what are pheromones. See spawning is a process of release or deposit of eggs by organisms like fish and frogs. And pheromones are hormones like chemicals. The difference between both is that while hormones are released inside the body, the pheromones are released outside the body. The next difference is that while hormones are chemical signals for our body's internal organs to communicate with itself, the pheromones are chemical signals used to communicate with other organisms of the same species. So now coming back to the question why do puffer fish spawn on beaches under moonlight? See the puffer fish normally spawn along the coast at night during spring tide. After studying the genetic makeup of the puffer fish, the scientists concluded that this behavior is due to a release of a particular pheromone called PGE2. See using this pheromone PGE2, the puffer fish communicate with each other and perform synchronized beach spawning. So this is about the puffer fish and its spawning behavior. Now while discussing about the behavior of the puffer fish, I mentioned that puffer fish normally spawn along the coast at night during spring tide and here what are the spring tides? See first of all tides are a periodic rise and fall in sea level due to the gravitational force exerted by the moon and the sun. In case of tides, it is the gravitational effect of the moon that plays an important role and the gravitational effect of the sun plays only a minor role. See we know that our moon revolves around the earth and it takes four weeks for our moon to complete one revolution around the earth right? So whenever moon revolves around the earth, at two moments the earth, sun and the moon fall in the same line. Once when the earth is between the sun and the moon and again when the moon is between the sun and the earth. So when the earth is between the sun and moon, we get that full moon day. Again when the moon is between sun and earth, we get the new moon day. So in both the cases, the gravitational pull of the sun is added to gravitational pull of the moon on earth. This will cause the oceans to bulge a bit more than usual. This is called the spring tide. We know that every coastal area experiences two high tides and two low tides every day due to the rotation of the earth right? But during spring tide as the gravitational pull of the sun and moon adds up the high tides a little higher and low tides are a little lower than average. But what happens when the sun and moon are at right angle to each other? See when this happens the bulge of the ocean caused by the sun partially cancels out the bulge of the ocean caused by the moon. This produces moderate tides known as neeptides. That is during neeptides high tides are a little lower and low tides are a little higher than average. An additional point to note here is that for every lunar month our earth experiences two spring tides and two neeptides. I hope now you could clearly understand why puffer fish spawn along the coast at night during spring tide. So, to know more interesting facts like these, do subscribe to Shankar Reyes Academy YouTube channel. Thank you for listening.