Conference Presentations by Suneth Gayashan
SLAFAR, 2019
In Sri Lanka, few numbers of fish species are cultured as food fish, mainly in seasonal reservoir... more In Sri Lanka, few numbers of fish species are cultured as food fish, mainly in seasonal reservoirs in the dry zone under culture based fisheries practices (CBF). Cadmium and its compounds which enter to the reservoirs through rain runoff are most common environmental toxicants with potential for bioaccumulation and persistence in the body, and produce versatile biotic changes in the aquatic ecosystem. Present study was designed to study the chronic exposure of ecologically relevant concentrations of cadmium (Cd) on the growth, bioaccumulation, and hematological parameters of genetically improved farmed tilapia (GIFT). Fish were exposed to two concentrations of Cadmium (50 µg/L and 100 µg/L) with control. The highest concentration of cadmium is based on the maximum tolerance limit for the discharge of industrial waste water in to inland surface waters (100.0 µg/L) which has been recommended by the Board of Investment (BOI) of Sri Lanka. Eight fish with initial mean weigh of 12.84±0.53 g were randomly assigned quadruplicated treatments and experiment was lasted for six weeks. Daily food consumption and survival of the experimental fish were recorded, and total length and weight measurements of fish were taken fortnightly. At the end of the experiment, growth performances and feed utilization efficiencies were assessed by using % specific growth rate (%SGR), % average daily gain (%ADG) and feed conversion ratio (FCR). At the end of the experiment, the pattern of Cd accumulation, its affinity to selected tissues (muscle, skin, liver and gills) and hematological parameters such as red blood count (RBC), white blood count (WBC), hematocrit (HCT) and packed cell volume (PCV) of the experimental fish were examined. Mean total length, body weight, %ADG, %SGR, HCT and PCV were not affected by the treatments. Significantly highest survival rate (100%) was observed in control followed by Cd50 (87.50%) and CD100 (78.13%). The rate of Cd accumulation in various tissues were in the order of liver > gills > muscle > skin in
This study was conducted to evaluate the chronic exposure of cadmium on growth performance, bioac... more This study was conducted to evaluate the chronic exposure of cadmium on growth performance, bioaccumulation, and hematological parameters of genetically improved farmed tilapia (GIFT). Two concentrations of cadmium (50 µgL-1 and 100 µgL-1) with control were used. Twelve fish with an initial mean weight of 12.84 ± 0.53 g were randomly assigned quadruplicated treatments (total 144 fish) and the experiment lasted for six weeks. In the end, growth performance and feed utilization efficiencies were assessed by using % specific growth rate (%SGR), % average daily gain (%ADG) and feed conversion ratio. The pattern of Cd accumulation in different tissues and hematological parameters were examined. Mean body weight, %ADG, %SGR, hematocrit and packed cell volume were not affected by the treatments. A significantly higher survival rate (100 %) was observed in control followed by CD50 (87.50 %) and CD100 (78.13 %). The rate of Cd accumulation in various tissues was in the order of liver > gills > muscle > skin in each treatment. Among tested concentrations, the highest accumulation was observed in CD100 for each tissue. Both red blood and white blood cell count (2.21 ± 0.07 × 10 6 mm-3 and 468.00 ± 6.61 × 10 3 mm-3 respectively) were significantly higher in control and it was lowest in CD 100 (1.28 ± 0.04 × 10 6 mm-3 and 205.19 ± 8.94 × 10 3 mm-3). The results of this study supported the conclusion that there is a significant effect of the chronic exposure to cadmium on the bioaccumulation and hematological parameters of the GIFT tilapia even at the ecologically relevant concentration.
Conference Proceeding by Suneth Gayashan
International Symposium on Agriculture and Environment, 2021
The present study was designed to evaluate the chronic exposure of iron (Fe) on the growth, haema... more The present study was designed to evaluate the chronic exposure of iron (Fe) on the growth, haematological and histological parameters of the Guppy (Poecilia reticulata). This experiment was conducted with four iron concentrations (3 ppm: Fe-3, 5 ppm: Fe-5, 10 ppm: Fe-10 and 20 ppm: Fe-20) and the control which does not contain added iron. The lowest concentration of iron is based on the maximum tolerance limit for the discharge of industrial wastewater into inland surface waters (3 ppm) which has been recommended by the Board of Investment (BOI) of Sri Lanka. Fifteen male fish with an initial mean weight of 0.20±0.04 g were randomly assigned in triplicated treatments and the experiment lasted for 45 days. Daily food consumption and survival of the experimental fish were recorded and weight measurements of fish were taken fortnightly. At the end of the experiment, growth performances and feed utilization efficiencies were assessed by using percentage specific growth rate (%SGR), percentage average daily gain (%ADG) and feed conversion ratio (FCR). Red blood cell count (RBC), blood smears and histological variations of gill tissues of the experimental fish were also examined at the end of the experiment. Mean body weight was not affected by the treatments. There were no structural alterations observed in blood smears of fish in different treatments. The lowest FCR (1.35±0.07) was observed in Fe-3 while the highest %ADG and %SGR both were observed in the control (4.30±1.21 and 2.37±0.44). Significantly (p<0.05) the highest survival rate (100%) was observed in control followed by Fe-3 (86.7±2.6%), Fe-5 (82.0±2.5%), Fe-10 (73.3±1.4%) and Fe-20 (10.0±0.7%). Among tested treatments, the highest RBC was reported in the control and Fe-3 (1.83±0.30 ×10 6 /mm 3 and 1.92±0.49 ×10 6 /mm 3 respectively) followed by Fe-5 (1.22±0.31 ×10 6 /mm 3), Fe-10 (0.99±0.21 ×10 6 /mm 3) and Fe-20 (0.61±0.13×10 6 /mm 3). Histological sections of the gill tissues showed that secondary lamellae were arranged without proper order and were visualized as broken or eroded, fused and misshaped filaments in the high Fe levels. However, these alterations were not observed in the Fe-3. The results of this study revealed that there is a significant effect of the chronic exposure of iron on the growth performance, red blood cell counts and histological status of the gills of the guppy at the concentrations greater than the BOI recommended level (3 ppm).
Papers by Suneth Gayashan
Tropical Agricultural Research and Extension, 2023
This study was conducted to evaluate the chronic exposure of cadmium on growth performance, bioac... more This study was conducted to evaluate the chronic exposure of cadmium on growth performance, bioaccumulation, and hematological parameters of genetically improved farmed tilapia (GIFT). Two concentrations of cadmium (50 µgL-1 and 100 µgL-1) with control were used. Twelve fish with an initial mean weight of 12.84 ± 0.53 g were randomly assigned quadruplicated treatments (total 144 fish) and the experiment lasted for six weeks. In the end, growth performance and feed utilization efficiencies were assessed by using % specific growth rate (%SGR), % average daily gain (%ADG) and feed conversion ratio. The pattern of Cd accumulation in different tissues and hematological parameters were examined. Mean body weight, %ADG, %SGR, hematocrit and packed cell volume were not affected by the treatments. A significantly higher survival rate (100 %) was observed in control followed by CD50 (87.50 %) and CD100 (78.13 %). The rate of Cd accumulation in various tissues was in the order of liver > gills > muscle > skin in each treatment. Among tested concentrations, the highest accumulation was observed in CD100 for each tissue. Both red blood and white blood cell count (2.21 ± 0.07 × 10 6 mm-3 and 468.00 ± 6.61 × 10 3 mm-3 respectively) were significantly higher in control and it was lowest in CD 100 (1.28 ± 0.04 × 10 6 mm-3 and 205.19 ± 8.94 × 10 3 mm-3). The results of this study supported the conclusion that there is a significant effect of the chronic exposure to cadmium on the bioaccumulation and hematological parameters of the GIFT tilapia even at the ecologically relevant concentration.
Uploads
Conference Presentations by Suneth Gayashan
Conference Proceeding by Suneth Gayashan
Papers by Suneth Gayashan