Question

The term ‘terror of Bengal’ is used for
A) algal bloom
B) Eichhornia crassipes
C) increased biochemical oxygen demand
D) eutrophication

Answer 1

Hint: It is a free floating aquatic plant having beautiful purplish flowers. It grows robustly on the surface of water in ponds and lakes.

Complete answer:
Eichhornia crassipes is commonly known as water hyacinth. It is a highly problematic species as it grows vigorously even outside its natural habitat. It is a free-floating perennial hydrophyte having broad, thick and ovate leaves with glossy surface and swollen petiole. It is one of the fastest growing plants reproduced mostly by runners or stolons, which ultimately gives rise to daughter plants. In addition to this, each plant produces thousands of seeds each year. The seeds have very long viability that is more than 28 years. In Bengal it was introduced due to its beautiful flowers and oval shapes of leaves, but it soon turned out to be an invasive weed. The hot and humid climate of Bengal is favourable for the growth of this plant. Water hyacinth strongly competes with other neighbouring plant species and animals living in water. Due to its vigorous growth it occupies the large surface area of water bodies. It drains oxygen and other nutrients from the water bodies thus, reduces the DO (dissolved oxygen) of the water that results in death of many fishes. In Bengal, fish is a supplement food and Eichhornia is the major causal agent for the fish scarcity. That is why water hyacinth is also known as "Terror of Bengal".

Thus, the correct answer is B, i.e., Eichhornia crassipes.

Note:Fish is a vital component of food for Bengali people. They also treat fish as a symbol of worship. As water hyacinth causes the death of fishes, it is also known as “beautiful blue devils” in Bengal.