| dc.description | Tilapia is one of the most important fish species and widely cultured all over the world to
meet the increased protein demand. It has considered as the Food Fish of the 21st century.
It is popularly known as aquatic chicken and become the third most important fish in
aquaculture after carps and salmonids because of their production (Fessehaye, 2006). The
world aquaculture production of tilapia is 4.0 million tonnes with an estimated value of
around $ 3 billion. FAO (2015) reports indicate that the Global tilapia production is
expected to reach 7.3 million tons by 2030. To meet the enormous demand for protein
source majority of the people depends largely on fishes which is cheap in comparison to
other protein sources in Bangladesh. After 1999, there was a tremendous progress in tilapia
farming in our country. According to DoF (2014), in 2012-2013 fiscal year the tilapia
production was 2,28,450 mt. which was 2,140 mt. in 1999-2000 fiscal year. In 2015-2016
fiscal year, the production of tilapia was 3,77,346 mt in Bangladesh contributing 9.73% of
total production (FRSS, 2017). | en_US |
| dc.description.abstract | An experiment was conducted to observe the water quality of tilapia farming. For the
purpose of the study, two types of farming practices were selected viz. nursery and growout of tilapia farming in Kaharole Upazilla under Dinajpur district. Three nursery and three
grow-out ponds from “Hye Hatchery” in Dinajpur district were selected for conducting the
experiment. Water sampling from grow out ponds were started for a period of 6 months
from April 2016 to September 2016. On the other hand, water samples from nursery ponds
were collected for a period of 2 months from November to December, 2016. Among
different water quality parameters only water level and temperature of nursery ponds
varied significantly. While in grow-out ponds, water temperature, transparency, dissolved
oxygen content, alkalinity and pH found to vary significantly with the size of the ponds
and sampling periods. However, the mean values of chlorophyll-a did not vary
significantly. The phytoplankton community in grow-out ponds consisting of 63 genera
representing four groups of phytoplankton such as bacillariophyceae (16), chlorophyceae
(32), cyanophyceae (13), euglenophyceae (2). While 21 genera belongs to four groups of
zooplankton viz.; copepoda (5), rotifera (10), cladocera (6) and crustacean larvae were
identified throughout the study period. A total of 61 genus of plankton were recognized
from nursery ponds. In the present study, 49 phytoplankton genus were identified with 26
belongs to chlorophyceae, 12 to bacillariophyceae, 9 to cyanophyceae and 2 to
euglenophyceae. Whereas, 12 genera of zooplankton consisting 6 genera of rotifera, 3 to
copepoda, 2 to cladocera and 1 to crustacean larvae. However, the planktonic communities
both in nursery and grow-out pond did not vary significantly throughout the study period.
Total mean (±SD) abundances of phytoplankton were recorded as 16.69±4.71, 16.41±4.64,
16.20±4.27× ͳͲଷ
cells/L in pond 1, 2 and 3 respectively in grow-out ponds. On the other
hand, the mean (±SD) abundances of total zooplankton were recorded as 7.33±2.85,
7.12±2.69 and 6.79±2.64 cells/L for pond 1, pond 2 and pond 3 respectively. The mean
values of total plankton were 23.55±×10³, 23.04×10³ and 22.51 ×10³ cells/L. While in
nursery ponds, the mean (±SD) abundances of total phytoplankton were 18.48±1.81,
18.58±2.01 and 18.61±1.06 (× ͳͲଷ
cells/L) recorded in sampling pond 1, 2, and 3
respectively. It can be concluded that the water quality parameters and planktonic
abundance of grow-out and nursery ponds found within optimum and suitable ranges. | en_US |
