Sri Lanka Journal of Aquatic Sciences最新文献

{"title":"Heavy use of antibiotics in aquaculture: Emerging human and animal health problems – A review","authors":"P. Manage","doi":"10.4038/SLJAS.V23I1.7543","DOIUrl":"https://doi.org/10.4038/SLJAS.V23I1.7543","url":null,"abstract":"Antibiotics have been extensively and effectively used in aquaculture due to accelerated growth of aquaculture and this has resulted in the development of serious health problems in aquaculture, other animals, and human. The use of a wide variety of antibiotics in large amounts, including non-biodegradable antibiotics, ensures that they remain in the aquatic environment for a long time. This has resulted; the emergence of antibiotic-resistant bacteria in the environments, an increase of antibiotic resistance in fish pathogens, transfer of these resistance determinants to bacteria and then land animals and finally become human pathogens along with alterations of the bacterial flora both in sediments and in the water column. Thus, the global efforts are needed to promote more judicious use of prophylactic antibiotics in aquaculture as accumulating evidence indicates that unrestricted use is detrimental to fish, terrestrial animals and human health.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"36 1","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73435329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are fancy guppies ( Poeciliareticulata Peters, 1859) invasive?","authors":"C. Bandaranayake, W. Chandrasekara","doi":"10.4038/SLJAS.V22I2.7536","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I2.7536","url":null,"abstract":"Guppies ( Poecilia reticulata Peters 1859) have been introduced to Sri Lanka in the early 1970s to combat the menace of Malaria. Due to their rapid range expansion in natural waterways, guppies are labeled as an ‘invasive species.’ Guppies are also popular in the ornamental fish trade where a wide variety of ornamental guppy varieties with attractive colour and fin patterns have been produced through selective breeding; they are commonly known as ‘fancy guppies’ or ‘saree guppies’. Since there are some concerns over the invasiveness of these fancy guppies into natural water bodies in Sri Lanka, the potential invasiveness of two common fancy guppy varieties with long caudal fins viz. black guppies and yellow guppies, was assessed under laboratory conditions using their specific growth rates (SGR) and critical swimming speeds (U crit ). Results in the present study showed that the SGR of black guppies (1.0 % g day -1 ), and yellow guppies (0.99 % g day -1 ) were significantly lower (p -1 ). Further, the U crit of the black guppies (23.8 cm s -1 ), and yellow guppies (26.8 cm s -1 ) were significantly lower (p -1 ). Since the long caudal fins significantly reduced  the swimming speed (p","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"98 1","pages":"117"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80932985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physicochemical environment of Malala Lagoon in Southern Sri Lanka","authors":"L. Titus, K. Deepananda, P. Cumaranatunga","doi":"10.4038/SLJAS.V22I2.7537","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I2.7537","url":null,"abstract":"Malala Lagoon is the largest of the five enclosed shallow lagoons in Bundala National park, and is one of the most productive of the fifteen lagoons in the Hambantota district, Sri Lanka.  It has been vulnerable to human induced pollution for nearly three decades. This paper ascertains the status of physicochemical environment of the lagoon and its temporal variation from 1995 to 1997. During the study period physicochemical and biological parameters measured in Malala lagoon were water temperature, pH, conductivity, Secchi depth, dissolved oxygen, salinity, total alkalinity, dissolved phosphate, and chlorophyll-a, and their mean values were; 27.69 ± 1.62°C, 7.93±0.46, 5.14±3.88 mS/cm, 00.39 ± 00.19 m, 7.83±0.89 mg/L, 2.18±1.61‰, 2.14 ±0.59 mmol/L, 12.25±4.67 mg/L and 8.86 ± 4.62 mg/L respectively. Maximum depth of the lagoon rarely exceeded 2 m during the study period. Due to the shallowness of the lagoon, there were no significant differences (p>0.05) in physicochemical parameters of surface, middle and bottom layers of the water column. Water level of the lagoon showed a significant (p<0.01) negative correlation with electrical conductivity (r = 0.727) as well as with the salinity (r = 0.729). Water influx to the lagoon showed a significant (p < 0.05) negative correlation with conductivity (r = 0.454) and salinity of the lagoon (r = 0.406). Findings of the study are compared with those carried out over a decade to explore and elucidate the long term changes in the lagoon environment. When compared with the published data from preceding and subsequent studies, it confirmed that the brackish water characteristics of the lagoon are gradually degrading due to pollution caused by natural phenomena and anthropogenic activities adversely affecting the ecological balance and the productivity of the lagoon. These findings could be of great importance when studying long term changes in the coastal waters, which are essential for sustainable coastal planning, with respect to socioeconomic development programmes as well as to identify the impacts of Hambantota port and maritime activities in the area and to understand the trends related to global climate change.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"13 1","pages":"129"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87248785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental factors contributing to the invasion of Najas marina L.in Madu Ganga estuary, a Ramsarwetland in Sri Lanka","authors":"T. Silva, M. Wijeyaratne","doi":"10.4038/SLJAS.V22I2.7540","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I2.7540","url":null,"abstract":"Najas marina is one of the nine invasive alien species that has been identified in the Ramsar wetland of Madu Ganga estuary in Sri Lanka. This aquatic macrophyte is a major threat to the ecological balance of this wetland ecosystem and also a nuisance to fishing and tourism industry associated with this wetland. Present study was conducted from March to November 2014 to identify the physicochemical parameters that affect the distribution of N. marina in this estuary. None of the physicochemical parameters studied namely depth, Secchi depth, water temperature, total dissolved solids (TDS), salinity, pH, dissolved oxygen (DO), biological oxygen demand (BOD 5 ), nitrate-N content, total dissolved phosphorous (TDP) content and total phosphorous (TP) content were not individually responsible for the invasion of N. marina . However, combination of some of these physicochemical parameters such as high salinity, high TDS, high BOD and high nitrate-N and TDP concentration favors the invasion of N. marina . The entire estuary is under the threat of invasion of N. marina except the area near the mouth of the river that flows in to the estuary due to the high rate of water flow.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"39 1","pages":"109"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90154902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Food and micro-habitat partitioning among cyprinids in Sri Lankan hill-stream pools","authors":"J. Vijverberg, J. Heidweiller, J. G. Sevenster, K. Kortmulder","doi":"10.4038/SLJAS.V22I2.7532","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I2.7532","url":null,"abstract":"Cyprinid fish assemblages in three stream pools in southwest Sri Lanka, were investigated with the objective of analysing species segregation, niche complementarity and degree of resource partitioning. Feeding ecology was studied by gut contents analysis and by direct underwater observations. Dietary data were related to the micro-distribution of the fish and to their horizontal distribution, the latter taken from previously published literature. Diet overlaps were calculated for each pool community and for the community as a whole. Resource partitioning among assemblage members was by diet, micro-distribution and horizontal macro-distribution. Among the three feeding substrates (rocky substrates, sand, dead leaves) rocky substrate was the most preferred, but other substrates, especially dead leaves, were used as well. Only Rasbora daniconius , which mainly fed high in the water column, fed always on rocky substrates at the relative rare occasions that it chose a firm substrate. Pethia nigrofasciata was the only species with a clear preference for sand. The assemblage could be divided into three guilds: (1) the surface feeders ( Devario malabaricus , Rasbora daniconius ) fed largely on terrestrial arthropods, (2) one generalist Systomus pleurotaenia which fed on all five strata, largely on terrestrial arthropods, ephemeropteran and chironomid larvae. (3) the bottom feeders ( Dawkinsia singhala, Pethia  cumingii , Pethia nigrofasciata , Puntius dorsalis ) who fed preponderantly on chironomid larvae. Of the three niche dimensions, horizontal macro-distribution, micro-distribution and diet, horizontal distribution may be the strongest segregating factor among these fish species. The contribution of diet was substantial only between feeding guilds. A relatively high degree of endemism (ca. 40 % is endemic to Sri Lanka) and habitat partitioning suggests that the cyprinid assemblages studied are predictable, co-evolved systems with competition serving as an importing structuring factor.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"65 1","pages":"71-84"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85111603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the water and sediment quality of a lotic water-body in the western coastal region of Sri Lanka using Rapid Bioassessment Protocol II (RBP II) of benthic macroinvertebrates","authors":"W. Wijeyaratne, K. Kalaotuwawe","doi":"10.4038/SLJAS.V22I2.7533","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I2.7533","url":null,"abstract":"The biotic indices used in Rapid Bioassessment Protocol II (RBP II) developed by United States Environmental Protection Agency was used to assess the feasibility of using benthic macroinvertebates as bio-indicators for monitoring water and sediment quality in Ja-Ela stream, which is a lotic water body in the western coastal region of Sri Lanka.  Five study sites to cover the entire length of the stream, which are in five different fringing land uses (undisturbed site, agricultural site, industrial discharge receiving site, densely populated urban site and a site close to the mouth of the stream) were sampled  for water and sediment quality parameters and benthic macroinvertebrates from April to October 2015. Shannon-Weiner diversity index (H`), Hilsenhoff Family Biotic index (FBI), Taxa richness (TRI), and Ehemeroptera, Plecoptera and Trichoptera (EPT) index were calculated for each site. Results indicated significant spatial variations in BOD 5 , COD, visibility, nitrate concentration and total phosphorus concentrations in the water, and total organic carbon content and particle size distribution in sediments. The highest mean values for H' (2.38), TR (13.6) and EPT (6.2) were recorded from the undisturbed site. Significantly higher FBI values are recorded from the industrial discharge receiving site (6.97) and the urban site (6.81), indicating that they are the most polluted sites with higher degree of organic pollution than other sites. These biotic index values showed significant correlations with sediment and water quality characteristics of the study sites (R 2 >0.5, p","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"102 1","pages":"85"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80598982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative laboratory trial on the effect of Sargassum wightii incorporated formulated feed on growth performance and immunity development of Asian sea bass Lates calcarifer (Bloch 1790): can it be an alternative to commercial feed?","authors":"H. Kodithuwakku, M. Parakrama, P. Heenatigala, V. Pahalawattaarachchi","doi":"10.4038/sljas.v22i2.7539","DOIUrl":"https://doi.org/10.4038/sljas.v22i2.7539","url":null,"abstract":"Asian sea bass ( Lates calcarifer ) is a high valued seafood throughout the world. Bacterial infections can cause huge losses in Asian sea bass culture and among them Aeromonas hydrophila is ubiquitous. Inclusion of bioactive compounds present in seaweeds into fish diets can enhance the fish growth and immunity combating the bacterial diseases. This study was conducted to determine whether feeding with Sargassum wightii incorporated feed could enhance immunity of the fish to bacterial infections. A feed trial was conducted using four treatments comprising a commercial feed, two formulated feeds incorporated with 20 g/kg and 40g/kg of S. wightii in each feed and a formulated feed without seaweed as the control diet . Three replicate tanks stocked with 15 advanced fingerlings were used for the each treatment and reared 40 days under the optimum conditions. Growth parameters were tested and effect of different feeds on growth performance was evaluated. Fish survival rate and cost of formulated feed were calculated. At the end of feed trial, nine fishes from each treatment were artificially challenged with 1.50 ppm dose of A. hydrophila and observed for 7 days. There was a significant difference in weight gain in commercial feed compared to other three treatments (P 0.05). The challenge with A. hydrophila showed 11.1% disease prevalence in L. calcarifer fed with 20g/kg of seaweed incorporated feed. Highest disease prevalence of 100% was recorded in fish that had been fed with the seaweed free formulation. The highest level of immunity enhancement was reported using the feed that contained 20g/kg seaweed. Production cost of formulated feed was lower than the commercial feed.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"25 1","pages":"99"},"PeriodicalIF":0.0,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90804063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproductive characteristics of Siahmahi, Capoeta damascina (family: Cyprinidae) in Beheshtabad river, Tigris basin","authors":"Masoud Siami, Y. Keivany, O. Farhadian","doi":"10.4038/SLJAS.V22I1.7513","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I1.7513","url":null,"abstract":"A total of 426 specimens of Mesopotamian barb (Siahmahi) Capoeta damascina (Cyprinidae) were caught by gillnets (1–6 cm mesh sizes) from Beheshtabad River, Chaharmahal and Bakhtiari Province from May 2013 to June 2014. Fish specimens were anesthetized in 1% clove oil solution, fixed in 10% buffered formalin and transported to the laboratory for further analyses. Fork lengths of the sampled fish ranged from 8.94 cm to 42.45 (23.32±6.53SD) cm and total weight from 10.3 to 1255.5 (242.5±213.4) g. Based on scale readings, the maximum age was found to be 7+ years for males and 8+ for females. Six reproductive characteristics, viz: sex ratio, Gonadosomatic Index (GSI), Hepatosomatic Index (HSI), relative fecundity, absolute fecundity and ova diameter were determined. The smallest mature male and female were 11.2 and 18.5 cm in fork length respectively. Sex ratio was 1M:0.7F. The GSI showed that spawning occurred from March to June. Oocyte diameters ranged from 0.57 to 2.48 (1.30±0.41) mm. Absolute fecundity ranged between 2260 and 51770 (15360±12030) eggs. Absolute fecundity and fish size (fork length and total weight) were highly correlated. Relative fecundity varied from 11 to 65 (33±12) eggs per gram of total body weight. The average hepatosomatic index was 2.25 ± 0.05 and the highest value was observed in March (3.05 ± 0.31).","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"28 1","pages":"21"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86578675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilization of minor cyprinids (Dawkinsia singhala and Puntius chola) from reservoirs as protein sources for feeds of juvenile koi carp (Cyprinus carpio)","authors":"Rochana Weerasingha, W. G. C. U. Soorasena, D. Athukorala","doi":"10.4038/SLJAS.V22I1.7515","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I1.7515","url":null,"abstract":"Six-weeks of feeding trial was conducted to evaluate the effect of diets formulated using fish meal made from minor cyprinids ( Dawkinsia singhala (DS) and Puntius chola (PC)) on the growth of koi carp ( Cyprinus carpio ) juveniles. Two isonitrogenous (crude protein -35 %) experimental diets with average lipid level (dry matter) of 8.96 ± 0.41 % (mean ± SD) were prepared containing 30.5% DS: 9% fish meal (FM) (T 1 ); 33% PC: 8% FM (T 2 ). Prima ® tropical fish feed was used as the control (T 3 ). Each treatment was followed by three replicates and nine cement tanks of 1.5 m ×1.2 m in size were used to conduct the study. Hundred juvenile koi fish with an average weight of 0.58±0.03 g (mean ± SD) were randomly allocated for each tank. At the end of feeding trial, no significant differences were found in weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate among fish fed 3 diets ( P >0.05). The results indicated that two minor cyprinid species selected in the present study could be utilized as a protein supplement in juvenile koi carp feeds to replace high cost fish meals.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"30 1","pages":"39"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82185994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of heavy metal concentration on bio-accumulation, productivity and pigment content of two species of marine macro algae","authors":"W. A. Anusha D. L. Wickramasinghe, V. K. Mubiana, R. Blust","doi":"10.4038/SLJAS.V22I1.7511","DOIUrl":"https://doi.org/10.4038/SLJAS.V22I1.7511","url":null,"abstract":"Environmental pollution due to heavy metals is a world-wide problem in estuarine, coastal and marine waters. Metal pollution affects different organisms in different ways and the degree of the impact is site-specific. Aim of the present study was to determine the effects of heavy metals viz., Cu, Cd and Pb exposure on tissue accumulation, pigmentation and productivity of two marine macro algae, Fucus vesiculosus and Ulva lactuca under controlled laboratory conditions. Algae were collected from a reference location, Wemeldinge in the Eastern Scheldet Estuary in Netherlands. Metal concentrations were determined using ICP-MS. Productivity of algae was measured using Winkler method and the results were expressed as carbon equivalent. Pigment profiles of two species were analyzed by spectral absorbance over 250 -1100nm range. The results revealed that the metal accumulation in tissues significantly increased with increasing exposure to metal concentration whereas, pigmentation, and photosynthetic productivity decreased with increasing metal concentration. Hence, F. vesiculosus and U. lactuca could be used as bio-indicators to determine metal pollution in coastal waters.","PeriodicalId":21784,"journal":{"name":"Sri Lanka Journal of Aquatic Sciences","volume":"17 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89722997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}