Which one of the following options includes all plants that are major non-native invaders of aquatic ecosystems in India?

Correct option is D

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Non-native invasive species disrupt aquatic ecosystems by competing with native species, altering habitats, and affecting biodiversity. 

1. Parthenium hysterophorus, Pontederia crassipes, Lantana camara → Incorrect

   • Parthenium hysterophorus and Lantana camara are invasive, but they primarily invade terrestrial ecosystems, not aquatic ones.
   • Pontederia crassipes (previously Eichhornia crassipes or water hyacinth) is an aquatic invasive plant.

2. Salvinia molesta, Prosopis juliflora, Mikania micrantha → Incorrect

   • Salvinia molesta is an invasive aquatic weed.
   • Prosopis juliflora and Mikania micrantha are terrestrial invasive species.

3. Nelumbo nucifera, Pogostemon erectus, Hygrophila serpyllum → Incorrect

   • These plants are not major invasive species in aquatic ecosystems.
   • Nelumbo nucifera (Indian lotus) is a native plant in India.

4. Pontederia crassipes, Salvinia molesta, Alternanthera philoxeroides → Correct

   • Pontederia crassipes (Water Hyacinth) is a notorious invasive species in Indian water bodies.
   • Salvinia molesta (Giant Salvinia) is a floating invasive fern that spreads rapidly.
   • Alternanthera philoxeroides (Alligator weed) is an aggressive aquatic invader.

Information Booster

1. Pontederia crassipes (Water Hyacinth): Originally from South America, it spreads rapidly in Indian lakes and rivers, clogging waterways and depleting oxygen levels.
2. Salvinia molesta (Giant Salvinia): A floating invasive fern from South America that forms thick mats on water surfaces, reducing oxygen and harming aquatic life.
3. Alternanthera philoxeroides (Alligator Weed): An invasive amphibious plant that disrupts water ecosystems by displacing native vegetation and affecting fish populations.
4. Impact of Aquatic Invasive Species: These species reduce biodiversity, block sunlight for native plants, lower oxygen levels, and disrupt local fisheries.
5. Control Measures: Biological control (such as introducing insects like Neochetina eichhorniae for water hyacinth), mechanical removal, and chemical treatments help manage these species.
6. Economic Losses: Invasive aquatic weeds increase maintenance costs for reservoirs, irrigation canals, and hydroelectric dams.
7. Conservation Efforts: Ecological restoration and strict monitoring help prevent the spread of non-native aquatic species in India.