Life And Death In A Pond (1981)

[Music] beneath the calm and Tranquil Waters of the pond living things struggle to survive and reproduce their kind creatures are born eat and are eaten reproduce and Die part of the Great continuing cycle of life and [Music] death [Music] winter brings a pause to the activities in the pond life slows but doesn't stop and then in early March even before all the Snows have melted the pond wakes from its winter sleep spring is a time of new life frogs mate while mating the male holds the female in a muscular grip called imp plexus during which he fertilizes her eggs as they are laid he'll cling tight for the rest of the day this ensures that no other male will fertilize his mate's eggs after his sperm is exhausted neither partner will eat or rest until amplexus is done frog eggs form in jelly-like clumps while towed eggs emerge as long peppery strings embedded in jelly but in both cases the jelly swells up when it touches water and allows the eggs to float in the pond in contrast to frogs and toads nutes mate without touching plain colored females seek out males with fancy markings each pair retires to a private spot on the Pond's bottom the excited male gives off pheromones enticing chemicals that he fans to his mate by wagging his tail the pheromones trigger responses in her body that prepare her to be [Music] fertilized the male releases his sperm in a neat white packet on the gravel the female stands over it and draws it up into her own body [Music] once her eggs are fertilized She lays them in private one by [Music] one [Music] the frog eggs will hatch early and the tadpoles will be first in line in the hunt for food each egg begins its development as soon as it's fertilized momentarily it is a one- celled animal but the cell divides and divides [Music] again every complex animal on earth begins life in the same stately [Music] dance the dividing cells take nourishment from the thin Yol that surrounds them during the first day the cells all look the same but they divide rapidly now there are hundreds thousands of tiny cells where there had been only one the pond waters are still cold but the energetic eggs and the sun's heat raised the Jelly's temperature and in this warmer environment the cells began to take different [Music] forms a slit appears which will soon fold into a tube this will become the animal's spinal cord in a week the embryos are visible to the naked eye and they are changing shape a head has grown at one end of the spine with bumps that will be eyes coiled inside are the tissues that will become stomach and intestine at this time most of the construction is internal the embryo has no limbs at all [Music] as nerve connects with muscle reflexes begin to Ripple through each tiny [Music] body suddenly at the end of 2 weeks the eggs Food Supply runs out the eggs must hatch for the embryo to survive each embryo fights to break out of its egg sack and the dangerous sticky [Music] jelly tadpoles seem to be born too soon how can they survive they have tails but no limbs or fins they breathe through fragile branching gills they are defenseless now out of all the masses of frog eggs laid in the pond a quar of a million tadpoles push off to search for food most will die in a few weeks because even as they hatch a dangerous predator is about to lay eggs nearby the diving Beetle injects her eggs into re seeds and [Music] stems like tadpoles when the diving beetles hatch they will not resemble their parents these are the young of the diving Beetle we call them water Tigers even as infants they pray on other inhabitants of the pond including tadpoles a water Tiger has no jaws and no stomach but its horns can inject stomach acids directly into a victim's body the acid injection dissolves a victim's innards into a sort of protein syrup which the water tiger sucks back into its own body through the [Music] horns it dines upside down breathing through a hole in its tail that pokes through the surface of the [Music] [Music] pond [Music] when the victim's body is an empty shell the meal is finished no Pond dweller is safe from a water tiger not even another water tiger below the surface the pond dwellers feed on each other while at the surface Ducks feed on the pond dwellers and above the pond the air fills with thousands of gnats and hot on their tails a hungry dragonfly dragonfly for legs are hairy Nets that scoop up the tiny insects as they hover over the water surface their wing muscles are so powerful and consume so much energy that they must bask in the morning sun for hours warming their bodies until they are ready to fly damsel flies are dragonfly relatives who carry their wings folded back rather than outstretched a damsel fly can eat its own weight in half an hour and must or die of starvation by mid-afternoon damsel flies mate in The Tall Grass near the Pond's Edge the male Loops himself under the female with a packet of sperm on his tail he slowly fertilizes her [Music] eggs some damsel flies lay eggs on the Pond's surface dropping them gently into the weeds below like frogs male damsel flies hang on until egg laying is complete protecting their genetic investment but their delicate mating Reigns impending death on the tadpoles below for damsel fly and dragonfly eggs as well hatch into nymphs pale hungry creatures who prey on Pond dwellers for as long as 5 years before emerging from the water as adults unlike water Tigers nymphs prowl the bottom of the pond looking for food [Music] [Music] a hungry n has its eyes on a nymph but the nymph has a secret weapon watch again the nymphs L jaw is like a long arm with a club on the end the N will find its meal somewhere else green algae stores solar energy tadpoles convert algae into animal tissue in the bodies of NES that solar energy is about to pass farther along the food chain [Music] [Music] w [Music] [Music] and the Pond life and death are always interwoven for a moment the tadpoles turn from their normal diet of algae and eat what's left of their former enemy even in death the N has a place in the pond snails and other scavengers finished the job the beetle began again and the cycle of Life continues tadpoles lost their external gills weeks ago but they still take oxygen from the water like fish for the lucky survivors a final metamorphosis begins legs break through the skin tails are absorbed slowly into their bodies eyes above the surface but the decisive moment is the opening of the lungs when the lungs expand the young frog must start breathing air from the quarter million tadpoles that were born in early spring perhaps 200 frogs escaped the pond in August and of these only 20 Will Survive land predators and live to hibernate at first Frost [Music] a pond surface looks calm and Serene but for its inhabitants the pond is one of the most competitive environments on [Music] Earth [Music]