Question

In a pond where water hyacinths are found to be flourishing,it is observed that submerged water plants could barely survive. What could be the possible explanation for the observation.​

Answer 1

Water hyacinth (Eichhornia crassipes) is a large aquatic plant native to the Amazon basin. Its thick, waxy, oval-shaped leaves are 4-8 inches across and branch out from the center of the plant on modified stems that may rise as much as 1 meter above the water surface. The mass of fine roots that hang in the water underneath the plant are dark purple or black with small, white root-hairs. The stems are spongy, bulbous stalks (called petioles) that contain air-filled tissues that keep the plant afloat. When flowering, the stalks support 8 – 15 blue-violet flowers with six petals each, with one petal being deeper violet with a yellow spot.

Answer 2

Answer:

They inhale oxygen through their gills or skin. Marine mammals have lungs and have to come to the surface to breathe.

They are cold-blooded, i.e., their body temperature is the same as the surrounding environment.

The collapsible lungs and rib cages help them to withstand very high water pressures.

The aquatic animals at great depths are bioluminescent, i.e., they emit light to attract preys and mates.

They have the property of osmoregulation, i.e., the fish can maintain an internal environment of salt and water.