Limnological studies and growth measurement of Egeria densa Planchn

Freshwater Hydrocharitaceae of Bangladesh is represented by 6 genera namely, Hydrilla, Blyxa, Nechamandra, Vallisneria, Ottelia and Hydrocharis (Khan and Halim 1987). Under these genera 9 species have been reported so far. Another member of the Hydrocharitaceae Egeria densa Planchn commonly known as Brazilian elodea is native to the coast of southeastern Brazil through Argentina, was also cultivated as an aquarium plant in the tropical fish business. In Bangladesh Egeria densa did not found till 2009. The plant material of Egeria densa was collected in a remote natural lake of Bangladesh namely Bogakine situated in the hilly Bandarban district in 2010. After collection the plant was transferred in the Botanical Garden, Department of Botany, University of Dhaka for culturing. Egeria densa showed an unique life cycle in the study period. The studied species showed significant relationship with climatic factors in respect to their growth and regeneration. Among nutrients phosphorus can be important. Scopes still exist to carry out similar meso-scale growth studies and limnological investigation on threatened aquatic macrophytes of Bangladesh.