| dc.contributor.advisor | Prof. Dr. Zannatul Ferdoushi | |
| dc.contributor.author | E-JAHAN, SITARA | |
| dc.date.accessioned | 2022-04-23T08:23:02Z | |
| dc.date.available | 2022-04-23T08:23:02Z | |
| dc.date.issued | 2017-06 | |
| dc.identifier.uri | http://localhost:8080/xmlui/handle/123456789/656 | |
| dc.description | Benthos, the bottom dwelling organisms are the integral part of an aquatic system.
Benthic organisms can be classified on the different basis. The benthic community
includes of a wide range of plants, animals and bacteria. They are broadly classified into
2 categories- Infauna-(organism that live in the sediment), Epifauna-(organisms which
either attach to the bottom or substrate; moves within the sediment; or that live on the
sediment surface). There are several categories occur, based on size: Macrobenthos
(more than 5 mm) e.g. Crab, insects and their larvae, other crustaceans, mollusks such as
gastropods, polychaete worms. Meiobenthos (size 0.1-0.5mm) e.g. ciliates, annilids,
copepods. Microbenthos (size smaller than 0.1 mm) e.g. Bacteria, flagellates, ciliates
(Brinkhurst 1974). | en_US |
| dc.description.abstract | An experiment was conducted in Dhepa River of Dinajpur district in order to study the
qualitative and quantitative abundance of macrobenthos with their seasonal variation.
The study also focused on the biodiversity index of benthos community. Two sampling
sites from Dhepa River in Dinajpur district were selected for research purpose. The
whole experiment duration was divided into three seasons such as summer, winter and
spring. Sampling was conducted at two sampling sites in Dhepa River from February
2016 to July 2016 and from November 2016 to January 2017. Physico-chemical
parameters of water and abundance of benthic community were determined. The
abundance of macrobenthos showed significant variation among the seasons and sites. A
total of 12 individuals representing three phylla such as mollusca, arthropoda and
annelida were identified. Of these 12 were mollusca represents 4, 5 individuals belonged
to arthropoda and 3 individuals belonged to annelida. Among the 5 genera of arthropoda,
chironomus was dominant. The abundance of total benthos found higher during summer
period (2398±639 individuals m-2) followed by winter (2266±631 individuals m-2) and
spring (1624±343 individuals m-2). Comparatively higher abundance of mollusca was
observed during winter season (1198±424 individual m-2) than other two seasons.
Similar observation was also recorded in case of arthropoda group (743±232 individuals
m
-2). Temperature showed positive relation with Chironomus, Gyrinus, Pheretima, Pila
and Melanoides sp. Transparency has negative significant relation with the abundance of
Forcipomyia sp. The abundance of Chironomous sp. and Tubifex sp. was decreased with
increase in water level. Similarly, total abundance of annelida was found higher during
summer (359±248 individuals m-2). Study sites from Dhepa river might be considered as
moderately polluted areas according to the results obtained from Shannon-Weaver index
of species diversity (1.64 to 2.30 respectively) and Margalef’s species richness (2.33 to
3.04 respectively). The evenness index of species diversity ranged from 0.59 to 0.98.
However, maximum biodiversity was recorded in muddy bottom and minimum was
recorded in sand bottom during the study period. This study would serve as baseline data
for water quality and abundance of macrobenthos population in a diverse riverine
system. Long term monitoring and improvement strategies are recommended to improve
macroinvertebrate population and quality of water. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | HAJEE MOHAMMAD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR | en_US |
| dc.subject | DHEPA RIVER | en_US |
| dc.subject | Seasonal variation in abundance of macrobenthos | en_US |
| dc.subject | Biodiversity indices | en_US |
| dc.title | MACROBENTHOS OF DHEPA RIVER IN DINAJPUR DISTRICT: SEASONAL VARIATION AND BIODIVERSITY ASPECTS | en_US |
| dc.type | Thesis | en_US |
