Ceratophylllum demersum L., commonly known as Coontail or Rigid Hornwort, is a rootless, free-floating aquatic macrophyte that is cosmopolitan in distribution. This species holds a dominant ecological niche and its diverse potentials in Loktak Lake, the largest freshwater lake in Northeast India and a Ramsar-designated wetland. This review is done based on published literature on the taxonomy, morphology, ecophysiology, distribution, allelopathic properties, and phytoremediation potential of C. demersum in the broader context of global literature. The present study reviews the ecology, distribution and significance of C. demersum. This rootless, submerged macrophyte has undergone significant expansion across the lake as a result of eutrophication and hydrological alteration following the construction of Ithai Barrage and nutrient loads from anthropogenic activities. However, this species exhibits a broad ecophysiological tolerance, demonstrate considerably phytoremediation potential, absorbing excess nitrogen, phosphorous and heavy metals from the water column. The dual nature of this species poses both challenges and opportunities for wetland management. The review identifies key knowledge gaps and proposes a long-term monitoring to restore the ecological balance of this globally significant wetland and for sustainable management of C. demersum L. This review underscores that sustainable management of C. demersum cannot be achieved through species-level interventions alone; it requires holistic watershed governance, restoration of natural hydrological regimes, and inclusive community participation.