Question

Which of the following species is also called as the "Terror of Bengal"?

• A. Clarias gariepinus
• B. Tectona grandis
• C. Eichhornia crassipes
• D. Tamarix dioica

Hint:

Prominent invasive plant species in India:
- Eichhornia crassipes (Water Hyacinth) = "Terror of Bengal".
- Parthenium hysterophorus (Carrot grass) = Imported with PL-480 wheat from the US.
- Lantana camara = Invasive ornamental shrub choking forest understories.

Answer 1

The Correct Option is C

Concept:
Invasive alien species are non-indigenous organisms introduced into new habitats outside their natural geographical range.
Lacking native predators and pathogens, they proliferate rapidly, outcompeting native taxa and disrupting ecosystem stability.

Step 1: Botanical and Historical Identity of the Species:
- {Eichhornia crassipes (commonly known as Water Hyacinth) is a free-floating aquatic macrophyte native to the tropical Amazon Basin in South America.
- It was introduced into Bengal, India, in the late 19th century as an ornamental garden plant due to its distinctive mauve-blue flowers and bulbous leaves.

Step 2: Ecological Impact in Bengal:
- Reproducing rapidly through vegetative offsets and stolons, the weed colonized rivers, drainage canals, lakes, and wetlands across Bengal.
- It forms dense, interlocking surface mats that block sunlight from penetrating the water column, preventing photosynthesis in submerged aquatic flora.
- When these large masses of water hyacinth die and decay, aerobic decomposers rapidly consume dissolved oxygen, creating hypoxic conditions that lead to widespread fish mortality.
- Because fish and rice are dietary and economic staples in Bengal, the widespread destruction of freshwater fisheries earned Eichhornia crassipes the title "Terror of Bengal".

Step 3: Verification of Other Options:
- Clarias gariepinus is the invasive African Sharptooth Catfish.
- Tectona grandis is Teak, a valuable deciduous timber tree.
- Tamarix dioica is a riverine shrub adapted to saline soils.
Final Answer:
The species known as the "Terror of Bengal" is Eichhornia crassipes, corresponding to option (C).