Browsing by Author "Jayakody, S."

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Allochthonus inputs into seasonal reservoirs: "Ornithological eutrophication" as a source of nutrient enrichment
(Sri Lanka Association for Fisheries and Aquatic Resources, 2010) Gunaratne, A.M.; Jayakody, S.; Amarasinghe, U.S.
The current study evaluates a lesser known allochthonus nutrient input into water sources, i.e. accumulation of bird faecal matter. Asian Open bill (An8stomus oscit8ns) population is increasing in Sri Lanka and due to mass breeding within reservoirs and higher population densities. Faecal matter could be a potential input of nutrients. Field investigations were carried out in Anavilundawa Ramsar sanctuary during 2007/08, where the reservoir was divided into four strata; inlet, breeding ground, centre and outlet. Surface and bottom water samples were analyzed for NO;, NH:, PO.... K+, hardness and dissolved oxygen (DO). Total depth, Secchi depth, temperature, turbidity and water pH were also recorded. In surface layers, the highest amount of NO; was recorded for breeding ground (0.55 mgr') followed by reservoir centre. The highest levels of PO... (0.93 mgr'), alkalinity (142 mgr') and NH: (1.9 mgr') were also recorded in breeding grounds. In the bottom layers. the highest level of NO; was recorded in breeding ground (0.49 m r') followed by reservoir centre. Similarly, the highest levels of PO."- (0.83 mgr ), alkalinity (147 mgr') and NH: (2.16 mgr') were recorded from the breeding ground. The lowest level of DO was recorded for breeding grounds 'both in surface layers (2.03 mgr') and bottom layers (0.84 mgr'). The lowest levels of pH were recorded for breeding grounds in surface layers (5.90) and bottom layers (5.93). The highest level of turbidity was recorded at the centre of reservoir for both surface water (30.95 NTU) and bottom water (2.76 NTU). Canonical variate analysis indicated the influence of ornithological eutrophication in water with four strata being significantly distinct for surface layer whilst, similarities in water quality in inlet and outlet for bottom layer. Hence bird faecal matter could be a constraint for maintaining water quality; however the results also suggest evidence for self regulation of water quality within the system. a character which needs to be retained.
Annual fluctuations in populations of sea urchin Stomopneustes variolaris (Lamarck. 1816) in two rocky shores of southern Sri Lanka
(Sri Lanka Association for Fisheries and Aquatic Resources, 2012) Thilakarathna, R.M.G.N.; Jayakody, S.; Amarasinghe, M.D.
Sea urchins play a key role in rocky shore habitats as grazers. They form urchin fronts and extensively graze on macro algae resulting in regions of barrens and restructuring the habitat. The population status of Stomopneustes var/alaris (Lamarck, 1816) of Phylum: Echinodermata Class: Echinoidea, the most abundant sea urchin species in intertidal zones of Sri Lanka was investigated from June 2008 to May 2009. The study evaluated the density of S. varialaris and the influences of macro algae cover in two rocky shore areas from Hikkaduwa (legally protected) and Ahangama (legally unprotected) in Southern Province. Three habitats (near shore, intermediate and splash) were selected in each site. Line transect and quadrate (50X50cm) sampling methods were used to measure macroalgae cover whilst S. variolaris density of each habitat was measured using belt transect method (10m X O.5m) every month. Mean percentage occurrence of algae and density of S. variolaris were analyzed using multivariate techniques and general linear models. Accordingly, Canonical Variate Analysis of flora confirmed the distinctiveness of the three habitats in relation to floral cover mainly due to differences in the dispersion of Hypnea pannasa and Graciaria sp. sp. in Hikkaduwa and due to Padina sp., Ulva lactuca and Jania ungulata in Ahangama. Ninety nine percent of the variation was explained by axes 1 and 2 in both Hikkaduwa and Ahangama. Mean densities of S. variolaris recorded for Hikkaduwa and Ahangama were 1.65:t0.46 m.l and 0.71 :t 0.22 m'l respectively and Hikkaduwa had a higher density compared to Ahangama (p< 0.05). In Hikkaduwa the highest mean density (3.56 :t 1.48 m'l) was recorded in splash zone (p < 0.05), whilst in Ahangama the highest mean density (1.42:t 0.53 m'l) was recorded in near shore habitat (p< 0.05). A non significant peak density was observed in the months of April and July in Hikkaduwa, and October in Ahangama. Results indicated S. variolaris inhabiting in higher numbers towards the sea in Hikkaduwa but in Ahangama near to coast, perhaps a response to greater disturbance in Hikkaduwa due to visitors.
Diurnal variation in the feeding patterns and food preferences of Dwarf panchax (Aplocheilus parvus)
(Sri Lanka Association for Fisheries and Aquatic Resources, 2015) Fernando, G.K.A.W.; Jayakody, S.; Wijenayake, W.M.H.K.; Galappaththy, G.N.L.; Yatawara, M.D.M.D.W.M.M.K.; Harishchandra, R.D.J.; Wanninayake, W.M.T.B.; Deniyage, S.L.
The food and feeding studies of fish are useful to explore the possibilities of using them for various purposes such as aquaculture and biological control of problematic organisms. In the current study feeding patterns and diet composition of Aplocheilus parvus (E: Killi fish/Drawft panchax), a common surface feeding predator inhabiting freshwater systems were explored. A. parvus was collected from an abandoned brick pit in Pannala in 2012. Twelve fish were caught every two hours for 24 hours. Plankton net was used to obtain a representative sample of food items present in the system. Gut fullness, total and standard length of fish, total weight and gut weight were determined and using copepod as an arbitrary unit, total numbers of food items of individual fishes were estimated. The time at which active feeding occurred was established from total food particle amount and relative gut weight. Diet of A. parvus mainly consisted of adult or larval stages of insects and copepods. Also, gut had a higher fullness in day time compared to night. The peak gut fullness occurred during 1630 in males whilst females had the peak gut fullness at 1230. Copepods were detected mostly during late morning, whilst insect parts and coleopterans were present in all time periods. Main food items detected in the environment in descending order of abundance were copepods, filamentous algae and insects. This study demonstrated that A. parvus selectively preys on insects compared to other aquatic food sources during day time.
The feeding patterns and food preferences of Aplocheilus parvus: a potential biological control agent for malaria?
(Sri Lanka Association for Fisheries and Aquatic Resources, 2012) Fernando, G.K.A.W.; Jayakody, S.; Wijenayake, W.M.H.K.; Yatawara, M.; Harishchandra, R.D.J.; Deniyage, S.L.; Galappaththy, G.N.L.
The ultimate aim of Anti Malaria Campaign is to eliminate indigenous malaria from Sri Lanka. Better environmental and economic benefits could be achieved by the use of indigenous fish species compared to chemical controlling methods as they have minimum or no impact on the existing aquatic fauna. Aplocheilus porvus is a common indigenous species available in both lotic and lentic systems in wet, intermediate and dry zones and is one of the surface feeding predators. The feeding pattern and food preference of A. parvus was determined to test its efficacy as a biological control agent for malaria larvae. A 24 hour sampling for A. porvus wos conducted (n=12 fish every 2 hours) at a brick pit in Pannala MOH region in Northwestern province positive for potential malaria larvae (Anopheles jomesii, 0.1l6/dip) between September 2011 January 2012. Gut fullness, total and standard length of fish, total weight and gut weight and using copepod as an arbitrary unit, total number of food items per 1ml of dissolved gut was calculated with a Sedgewick Rafter Cell. The time at which active feeding occurred was established from total food particle amount and relative gut weight (gut weight/total weighx100). Diet of A. porvus mainly consisted of adult or larval stages of class Insecta (Coleoptera, Hymenoptera and other unidentified insect parts and insect larvae) and class Maxillopoda (Copepoda). Also, gut had a higher fullness in day time (4.3:t0.121) compared to night (2.4:t0.120) (p
Fluctuations in Avian Distribution and Diversity in Anavilundawa Ramsar Sanctuary
(Department of Wildlife Conservation, 2014) Gunaratne, A.M.; Jayakody, S.; Amarasinghe, U.S.
Many of the seasonal water bodies in Sri Lanka harbour substantial numbers of aquatic birds. Local aggregation of water fowl during communal roosting and colonial breeding results in substantial inputs of nutrients into aquatic systems and can alter fresh water aquatic systems. The present study calculated the density and species richness of true aquatic bird and aquatic associated bird species in Anavilundawa Sanctuary (Ramsar Site) from July 2007 to July 2008 using the point count method. In Anavilundawa reservoir, the number of true aquatic bird species was higher (40.49 ± 1.251 birds ha-1) than the number of aquatic associated bird species (3.40 ± 0.437 birds ha-1). Amongst true aquatic birds recorded in the study area, Anastomus oscitans (Asian openbill) was the most abundant species (137.43 ± 7.246 birds ha-1). Further, Asian openbill inhabited only the Anavilundawa reservoir for nesting and breeding. Density and species richness of birds were the highest during rainy season when migratory species also arrived at the site. During the rainy season; the highest bird density was recorded in tree-covered habitats (11.72 ± 1.683 birds ha-1) followed by shallow open water habitats (2.05 ± 0.724 birds ha-1) and grass covered habitats (1.84 ± 0.579 birds ha-1). The lowest bird density was recorded in deep open water habitats (0.40 ± 0.263 birds ha-1). During the dry season when the migratory species left the area a few resident species have engaged in nesting activities. During the dry season too, the highest bird density was recorded in tree covered habitats (1.57 ± 0.497 birds ha-1) followed by grass covered habitats (0.99 ± 0.317 birds ha-1) and shallow open water habitats (0.63 ± 0.374 birds ha-1). Red-wattled Lapwing was the most abundant aquatic associated species recorded (2.05 ± 1.137 birds ha-1). The result also showed that true aquatic birds have the highest species diversity i.e., Shannon’s index (N1 = 2.233), species richness i.e., Margalf’s index (R1 = 2.015), Menhinick’s index (R2 = 0.782) and species evenness (E = 0.899) which were much higher compared to aquatic associated birds. It is concluded that Anawilundawa Sanctuary has retained its potential as an important ecosystem for avifauna despite human mediated disturbances.
“Ornithological eutrophication” as a source of allochthonous nutrient enrichment in Anavilundawa reservoir, Sri Lanka
(2015) Gunaratne, A.M.; Jayakody, S.; Amarasinghe, U.S.
Mass aggregation of waterfowls for breeding, results in allochthonous nutrient inputs intoaquatic systems. This study evaluated accumulation of bird droppings as allochthonusnutrient input and its ﬂuctuations in Anavilundawa International Ramsar Sanctuary in SriLanka where Asian openbill (Anastomus oscitans) mass breeding occurs annually. Reservoirwas divided into four strata: Inlet, breeding ground, reservoir centre and outlet. The highestnutrients levels (NO3,PO43,NH4þ, alkalinity) and the lowest dissolved oxygen and pHlevels were recorded in breeding grounds for both surface and bottom water. The highestturbidity was recorded in inlet surface and centre bottom water. Canonical Variate Analysis ofwater quality parameters indicated the signiﬁcantly distinct inﬂuence of ornithologicaleutrophication on surface water of four strata whilst, showing similarities in water quality ofbottom layers in inlet and outlet. In the breeding ground, surface water was covered with thickmats of aquatic ﬂora consisting of Water hyacinth, Salvinia, duckweed and Polygonum.Therefore, it is concluded that in addition to dilution, amelioration of water quality could alsobe happening due to absorption by plants. Due to interactions between invasive plants andwaterfowls, restoration with native aquatic ﬂora is needed to be considered to regain reservoirresilience and self-sustenance.
Quality of Life in Dementia Patients: Cross-Cultural Adaptation and Validation of Sinhala version of Dementia Specific Quality of Life (DEMQOL) in Sri Lanka.
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Jayakody, S.; Arambepola, C.
Dementia has become a public health priority along with population ageing worldwide. Owing to its chronic progressive nature in the absence of a cure, maintaining the best possible quality of life (QOL) have become the desired outcome for people with dementia. In the absence of valid tools to measure QOL, its current status is not known in the Sri Lankan setting. The current study aimed to perform a cross-cultural adaptation and validation of Sinhala version of DEMQOL and DEMQOL-proxy in Sri Lankan setting. DEMQOL and DEMQOL-proxy tools were initially translated, culturally adapted using modified Delphi process with a panel of experts, and tested for judgmental validity. Its construct validity was assessed by conducting a validation study among 100 patient-primary caregiver dyads attending state hospital psychiatry clinics in Gampaha District, by performing confirmatory factor analysis (CFA). Reliability was assessed using test-retest method and internal consistency. Mean age of patients with dementia was 72 years (SD=7.6) with a female preponderance (63.3%). Majority had studied up to ordinary level (68.3%). Dementia severity was assessed using mini mental state examination (MMSE) and only mild to moderate patients were included (mean MMSE score=17.32) in the study. Majority of the caregivers were female (73.3%) with a mean age of 55 years (SD=14) and 51% had studied up to advanced level. During CFA, the original four-factor model emerged with DEMQOL validation data, whereas a five-factor model was best fitted with DEMQOL-proxy validation data. Internal consistency and test re-test reliability of DEMQOL (Cronbach’s alpha=0.87; correlation coefficient=0.864) and DEMQOL-proxy (Cronbach’s alpha=0.874; correlation coefficient=0.834) were satisfactory. Sinhala version of the DEMQOL and DEMQOL-proxy scales are valid and reliable tools to assess the QOL of dementia patients of mild-moderate severity in Sri Lanka. Patients can successfully rate their own QOL.