Movements of some indigenous riverine fish in Sri Lanka

The migratory movements of reproductive potamodromus fish established in man-made tropical lakes in the dry zone of Sri Lanka were determined. It was shown that the nine indigenous riverine species do not spawn in these lakes but move into the upstream channels when sexually mature. The pattern of upstream movement was found to be species-specific although most species showed a diurnal periodicity. It is suggested that the development of totally lacustrine forms of riverine species is very unlikely to occur in the man-made lakes of Sri Lanka because of their relatively short duration time.     

The Cladocera of Sri Lanka (Ceylon), with remarks on some species

The freshwater Cladocera of Sri Lanka has been revised based on the study of over 700 zooplankton samples collected from all habitat types during 1965–1980. The cladoceran fauna is represented by six families; members of the families Polyphemidae, Leptodoridae and Holopedidae are absent. The common temperate genus Daphnia is rare.Sixty-two species have been recorded from Sri Lanka. Of these, five are new records. Remarks on a few species are given with illustrations. The distribution of Cladocera in different types of habitats is discussed. The greatest species diversity was found in ponds. The Sri Lankan fauna is numerically and in species diversity typical of tropical cladoceran fauna. It resembles the southern Indian fauna very closely except for the absence in Sri Lanka of the genera Acroperus and Camptocercus.     

The Freshwater Zooplankton of Sri Lanka,with a Discussion of Tropical Freshwater Zooplankton Composition

Based on the study of over 500 zooplankton samples collected in Sri Lanka (Ceylon) during 1965–1974, the species composition from different habitats is analysed. The zooplankton assemblage is typically tropical with relatively few species of Cladocera and Copepoda. The Rotifera include a large number of species of the genus Brachionus. The limnetic zooplankton resembles the pond zooplankton closely in that all the eurytopic species found in the different types of habitats, including ponds, also occur in the limnetic zooplankton. The large Cladocera belonging to the genus Daphnia are very rare. In general, large zooplankters are absent. The size composition of the zooplankton has a smaller range than in temperate regions. This is due to the absence of large-sized zooplankton species. The reasons for the differences in species variety and size composition between zooplankton of temperate and tropical regions is perhaps due to a number of factors. These include the effects of high and uniform temperatures, food availability and predation by fish and invertebrates.     

On Indiacypris luxata (Brady), a freshwater ostracod (Crustacea: Entomostraca) from Sri Lanka

Indiacypris luxata (Brady), a freshwater ostracod from Sri Lanka is described and both the valves and the limbs and soft parts are figured.     

Constraints to the implementation of biological control in Sri Lanka

Sri Lanka is a tropical island with a rich diversity of arthropods, with many species of indigenous natural enemies of economic pests. However, no extensive island wide surveys have been carried out for natural enemies of major crop ecosystems and only a few of the indigenous natural enemies are reported useful for augmentation biological pest control by massive field releases of laboratory-produced insects. Most successful biological control programs on the island are importation (i.e. classical) biological control programs, where established exotic natural enemies control certain pest populations in valuable crops. There is growing interest in the use of native natural enemies in pest management, thus creating a need for intensive research on the ecology of indigenous natural enemies and development of infrastructure and technology to produce natural enemies for augmentation. This paper examines constraints and opportunities for implementation of biological control in Sri Lanka.     

The seasonality of monsoonal primary productivity in Sri Lanka

The relationship between phytoplankton primary production and seasonality of physico-chemical parameters were examined for five man-made lakes in the dry-zone of Sri Lanka. Sri Lanka experiences two monsoons dividing the year into four meteorological seasons: — the North East (October–December) and South West (April–June) monsoons and the two inter-monsoons. A significant log linear relationship was found between Secchi disc depth and the depth of the euphotic zone which was lowest during the NE monsoon. Maximum mean photosynthetic rate ranged from 0.935 ± 0.067 SE to 0.479 mg O₂l^–1 h^–1 ± 0.115. Gross primary productivity which ranged from 0.378 g O₂ m^–2 h^–1 in the NE monsoon to 0.980 g O₂ m^–2 h^–1 in the SW monsoon showed significant season variation. This is shown to be determined either directly or indirectly by the light regime.     

Anthropophagy and aggregation behaviour of the sandfly Phlebotomus argentipes in Sri Lanka

ABSTRACT. The visceral leishmaniasis (VL) vector Phlebotomus argentipes Annandale & Brunetti is widely distributed throughout the Indian sub-continent and S.E. Asia. The absence of VL in areas such as Sri Lanka has been attributed to the zoophilic nature of P.argentipes , since they were not recorded biting man.
Field studies on P. argentipes were undertaken in the central highlands of Sri Lanka, near Kandy, in May 1988. Male sandflies outnumbered females on cows by 19:1, and were regularly spaced at all densities. This behaviour is considered analagous to swarming in other Nematocera. However, all-night human-biting catches show the biting rate to be similar (mean=8.4, range 2–25 bites per night over ten consecutive nights) to that in N.E. India where VL is endemic. This anthropophagy was maintained during laboratory colonization.     

Helicobacter pylori in School Children From the Western Province of Sri Lanka

Background. Little is known about the prevalence of Helicobacter pylori in Sri Lanka and nothing is known about its prevalence in children. Therefore the prevalence of H. pylori in a group of school children in Sri Lanka was determined. Materials and Methods. The presence of H. pylori colonisation was determined by detection of faecal antigen and salivary antibody (IgG) by enzyme immuno assay, in 184 children aged between 5 and 19 years, in the Western Province‐Colombo district of Sri Lanka. Results. Overall, only 12/184 (6.5%) had detectable H. pylori antigen in their stools and were considered infected with H. pylori, while 51/184 (27.7%) had H. pylori IgG in saliva. H. pylori salivary IgG declined with age while H. pylori antigen detection increased with age. H. pylori infection, as determined by salivary antibody (66%), was greater in children living in overcrowded conditions, although this was not statistically significant. Conclusion. The prevalence of H. pylori among school children in Sri Lanka was 6.5% by detection of faecal antigen and 27.7% by detection of salivary antibody, respectively. Initial infection with H. pylori appeared to occur in early childhood whilst active disease began in late childhood. Overcrowding appears to facilitate the transmission of the organism. Overall the prevalence of H. pylori was low in Sri Lanka compared with other countries in South‐east Asia.     

Chromoblastomycosis – A clinical and mycological study of 71 cases from Sri Lanka

Chromoblastomycosis, a well-documented chronic fungal infection, represents a specific clinical entity with typical warty cutaneous nodules and a worldwide distribution. Although more prevalent in tropical and subtropical regions, only a few reports are available from Sri Lanka or from Asia. Five etiologic agents of chromoblastomycosis have been recognized worldwide. Of these the majority of infections have been caused by Fonsecaea pedrosoi. During the period from 1952 to 1962, only twelve culturally proven cases of this disease had been recorded from Sri Lanka. The fungus responsible was F. pedrosoi. The present report presents a study of the clinical and mycological features of 71 Sri Lankan patients with chromoblastomycosis for the 16-year period from 1978 to 1993. It documents three etiological agents. Culture identification was made in 69 cases. The three fungal species were Fonsecaea pedrosoi (64), Phialophora verrucosa (3) and a fungus compatible morphologically with F. compacta (2). The isolation of a fungus morphologically compatible with F. compacta is of significance since only 12 cases have been documented in the world's literature so far. This revised version was published online in June 2006 with corrections to the Cover Date.     

Seasonality of mortality in Sri Lanka: Biometeorological considerations

The seasonal variation of mortality in Sri Lanka was studied in relation to meteorological variables. Time series data of the total monthly number of deaths in men and women from 1976 to 1980 were analyzed by power spectrum analysis of the fast Fourier transformation method in the areas of Colombo (lowland area, altitude 7 m) and Nuwara-Eliya (highland area, altitude 1890 m), respectively. In the Colombo area, where the mean temperature was always high (mean, 27.5 °C), a seasonal variation in mortality of 6 months was validated by power spectrum analysis with peak times in June and November. These mortality peaks corresponded to those of the amounts of rainfall which also showed an identical predominant period of 6 months. In the Nuwara Eliya area, where the mean temperature was always low at about 15–16 °C, a seasonal variation of approximately 3 months was found in addition to the 6 months' periodicity. The comparison of the power spectrum pattern of mortality with those of meteorological variables suggested that the amount of rainfall was associated with the seasonal variation of mortality in the Nuwara-Eliya area. In conclusion, the seasonality of mortality in Sri Lanka, a typical tropical zone country, was related to seasonal variation in the amount of rainfall, or a humidity factor, but not to mean temperature.     

Stocking Rate Estimations of Tilapia mossambica Fingerlings for some Inland Reservoirs of Sri Lanka

The Morphoedaphic Indices for several Sri Lanka inland water bodies (mostly ancient man-made reservoirs) were calculated using conductivity and depth data. The relationship between Morphoedaphic Index MEI and the annual catch of fish C was found to be . Using this equation, the annual potential yields were calculated. The stocking densities of Tilapia fingerlings needed to be stocked were then estimated taking into consideration the natural recruitment of fingerlings from the already existing stocks of reproducing Tilapia.     

Niche dynamics of Memecylon in Sri Lanka: Distribution patterns,climate change effects,and conservation priorities

Recent climate projections have shown that the distribution of organisms in island biotas is highly affected by climate change. Here, we present the result of the analysis of niche dynamics of a plant group, Memecylon, in Sri Lanka, an island, using species occurrences and climate data. We aim to determine which climate variables explain current distribution, model how climate change impacts the availability of suitable habitat for Memecylon, and determine conservation priority areas for Sri Lankan Memecylon. We used georeferenced occurrence data of Sri Lankan Memecylon to develop ecological niche models and assess both current and future potential distributions under six climate change scenarios in 2041–2060 and 2061–2080. We also overlaid land cover and protected area maps and performed a gap analysis to understand the impacts of land‐cover changes on Memecylon distributions and propose new areas for conservation. Differences among suitable habitats of Memecylon were found to be related to patterns of endemism. Under varying future climate scenarios, endemic groups were predicted to experience habitat shifts, gains, or losses. The narrow endemic Memecylon restricted to the montane zone were predicted to be the most impacted by climate change. Projections also indicated that changes in species’ habitats can be expected as early as 2041–2060. Gap analysis showed that while narrow endemic categories are considerably protected as demonstrated by their overlap with protected areas, more conservation efforts in Sri Lankan forests containing wide endemic and nonendemic Memecylon are needed. This research helped clarify general patterns of responses of Sri Lankan Memecylon to global climate change. Data from this study are useful for designing measures aimed at filling the gaps in forest conservation on this island.     

Relationship of environmental changes in central Sri Lanka to possible prehistoric land-use and climate changes

A radiocarbon-dated pollen-analysed peat sequence from the Horton Plains (> 2000 m a.s.l.), in central Sri Lanka, together with physical and chemical parameters (organic carbon, mineral magnetics, carbon isotopes and phytoliths), indicates major environmental changes during the last 24,000 years. The results suggest that a mobile life form, i.e. a hunter–forage culture, predominated in an open landscape, associated with xerophytic vegetation, e.g. Chenopodium spp. at  17.5 ka BP. Incipient management of cereal plants and slash-and-burn techniques seem to have prevailed between 17.5 and 13 ka BP, which was indigenous and associated with grazing. Evidence of systematic cereal cultivation in the form of oat and barley pollen grains is found from the late Pleistocene ( 13 ka BP). This is the earliest evidence of farming activities noted in Sri Lanka as well as in south Asia. After 13 ka BP, cereal cultivation was associated with an increase in humidity. With a later abrupt increase in aridity, agricultural land-use decreased from  8 to  3.6 ka BP, when the area appears to have been almost deserted. After a severe middle Holocene arid phase (i.e. 5.4–3.6 ka BP), the agricultural activity with a limited extension was again initiated by  2.9 ka BP. During the next  900 years, cultivation ceased allowing the upper montane rain forest to dominate. Between 0.2 and 0.15 ka BP, new phases of agricultural activities were undertaken and potato cultivation took place lately, between 1950 and 1969 AD.     

Behavioral Response of Satellite‐collared Elephants to the Tsunami in Southern Sri Lanka1

After the Asian tsunami the media was inundated with reports of aberrant behavior among animals attributed to a “sixth sense” that allowed them to respond to the catastrophe ahead of the impact. We present behavior data from two satellite‐collared Asian elephants that ranged close to the tsunami impact area in Sri Lanka. These data indicate that neither elephant behaved in a manner consistent with a “sixth sense” that allowed an early detection of the approaching tsunami.     

Memories of ethnic violence in Sri Lanka among immigrant Tamils in the UK

This article contributes to recent studies on the relationship between ethnicity and memory in the formation of transnational communities. The focus of the article is migrant Tamils' memories of violence in Sri Lanka in 1958, in the aftermath of an act declaring Sinhala to be the sole language of administration in the country. The ways in which past violence is remembered by this overlooked older generation helps in understanding the particular impetus of the contemporary Tamil diaspora, which continues to play a key role in shaping the image of Sri Lanka abroad. Research on the formation of the diaspora must therefore be situated within a more concrete history of relations between Sinhalese and Tamils in post-independence Sri Lanka.     

Mitochondrial DNA-based analysis of genetic variation and relatedness among Sri Lankan indigenous chickens and the Ceylon junglefowl (Gallus lafayetti)

Indigenous chickens (IC) in developing countries provide a useful resource to detect novel genes in mitochondrial and nuclear genomes. Here, we investigated the level of genetic diversity in IC from five distinct regions of Sri Lanka using a PCR-based resequencing method. In addition, we investigated the relatedness of IC to different species of junglefowls including Ceylon (CJF; Gallus lafayetti ), a subspecies that is endemic to Sri Lanka, green ( Gallus varius ), grey ( Gallus sonneratii ) and red ( Gallus gallus ) junglefowls. A total of 140 birds including eight CJF were used to screen the control region of the mitochondrial DNA sequence for single nucleotide polymorphisms (SNPs) and other variants. We detected and validated 44 SNPs, which formed 42 haplotypes and six haplogroups in IC. The SNPs observed in the CJF were distinct and the D-loop appeared to be missing a 62-bp segment found in IC and the red junglefowl. Among the six haplogroups of IC, only one was region-specific. Estimates of haplotype and nucleotide diversities ranged from 0.901 to 0.965 and from 0.011 to 0.013 respectively, and genetic divergence was generally low. Further, variation among individuals within regions accounted for 92% of the total molecular variation among birds. The Sri Lankan IC were more closely related to red and grey junglefowls than to CJF, indicating multiple origins. The molecular information on genetic diversity revealed in our study may be useful in developing genetic improvement and conservation strategies to better utilize indigenous Sri Lankan chicken resources.     

Anti-Rhinosporidial Antibody Levels in Patients with Rhinosporidiosis and in Asymptomatic Persons,in Sri Lanka

The only report hitherto, from India in 1982, on anti-rhinosporidial antibody levels in patients with rhinosporidiosis recorded that antibody was not detected in Indian patients. The present report describes the use of the dot-ELISA assay of serum anti-rhinosporidial IgG, IgM and IgA and salivary sIgA in patients with diverse clinical presentations, in rural asymptomatic persons who had bathed in ground waters that probably harboured the causative pathogen, Rhinosporidium seeberi, and in laboratory persons who were exposed to R. seeberi. Ultrasonic extracts of purified endospores and sporangia of R. seeberi were used as antigen. The geometric mean (reciprocal) titres of serum antibody detected in patients were IgM 142.1, IgG 178.5, IgA 84.6, with ranges of 0-640, 30-960 and 0-160 respectively, salivary sIgA titres ranged from 0 to 18 with a mean of 4.6. The levels of antibody had no correlation with the site, the number of sporangia, duration and recurrence of the disease. Asymptomatic persons from the same endemic area as patients showed mean titres of IgM 89.6, IgG 69.1, IgA 95.5, with salivary sIgA titres of 3.1. Asymptomatic personnel who had been working in a laboratory where rhiniosporidial work was being done, showed mean titres of 169.6 IgM, 62.8 IgG, and 6.5 salivary sIgA. These results indicate that an anti-rhinosporidial antibody response occurs in rhinosporidial patients, as well as in asymptomatic persons who were exposed to R. seeberi in the environment. Anti-R. seeberi antibody does not appear to be protective in rhinosporidiosis since appreciable titres were present in patients with recurrent, single, multiple or disseminated lesions of long duration.     

Sublineages of Beijing Strain of Mycobacterium tuberculosis in Sri Lanka

Strains of the Beijing/W genotype of Mycobacterium tuberculosis have been responsible for large outbreaks of tuberculosis around the world, sometimes involving multi-drug resistance. It has been shown that more recently evolved Beijing sublineages are prone to cause outbreaks. Furthermore Beijing is the single predominant cluster in Sri Lanka. The present study identifies that recently evolved sublineages of Beijing strains are present in the study population. The majority of Beijing isolates (92.85%) were pan-susceptible. However, these findings may have important implications for the control and prevention of tuberculosis in Sri Lanka.