| dc.description.abstract | Ratargul swamp forest is only the freshwater swamp forest of Bangladesh which supports diverse
fisheries communities compared to others. The present study was conducted from April to October
2015 to assess the status of indigenous fish species of Ratargul swamp forest along with relevant
hydrological and ecological aspects. A total 62 fish species comprising 28 threatened species were
recorded from the study area. Cypriniformes (37.46%) was the most dominant order followed by
Siluriformes (35.123%), Perciformes (19.456%), Synbranchiformes (3.298%), Clupeiformes
(2.282%), Beloniformes (1.161%), Osteoglossiformes (0.725%), Tetraodontiformes (0.462%) and
Anguiliformes (0.026%). Among the identified fish species 19.98% was recorded as threatened
according to IUCN (International Union for Conservation of Nature). The Mean Shannon-Wiener
diversity index, Margalef richness index, Pielou’s evenness index and Simpson dominance index were
found to be 3.690±0.191, 9.497± 1.314, 0.971±0.003 and 0.982±0.003, respectively. In case of
SIMPER (Similarity Percentages) analysis the highest number of similar species was found during
July to August and the lowest during April to October. At the similarity of 76.9%, four groups were
attained where June, July, August and September showed in a cluster while April, October and May
showed separate clusters. Non-metric Multidimensional scaling shows 60% similarity for all months.
On the other hand, 70% similarity observed among all the months except April. Environmental
parameters such as photoperiod, rainfall, relative humidity, temperature, transparency, dissolved
oxygen, p
, ammonia and nitrite were determined and found in acceptable limit for fisheries
communities. Diversity of plankton assemblage were assessed and a total of 34 planktons belonging
to Chlorophyceae (10 taxa), Bacillariophyceae (4 taxa), Cyanophyaceae (6 taxa), Euglenophyceae (2
taxa), Rotifer (4 taxa), Cladocera (5 taxa), Copepods (2 taxa) and Protozoans (2 taxa). A total of 8
major groups of benthos were identified including Oligichaetes, Polychaetes, Gastropods, Bivalvia,
Copepods, Isopods, Crab and Prawn larvae. A total of 20 different species were identified which
belongs to Emergent (15 taxa), Floating (3 taxa) and Submerged (2 taxa). It may be concluded that
Ratargul swamp forest is enriched with fish biodiversity having 28 threatened fish species of
Bangladesh.
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