Identities of two Paragonimus species from Sri Lanka inferred from molecular sequences

Metacercariae of Paragonimus spp. were obtained from field-collected freshwater crabs in Sri Lanka. Genomic DNA was extracted from single metacercariae. Two gene regions (partial mitochondrial cytochrome c oxidase subunit 1 (CO1) and the second internal transcribed spacer of the nuclear ribosomal gene repeat (ITS2)) were amplified using the polymerase chain reaction. Two differing sequences were obtained for each of these gene regions. Phylogenetic analyses placed the type 1 sequences as sister to a clade containing P. westermani and P. siamensis whereas the type 2 sequences were close to published sequences of P. siamensis from Thailand. The possible taxonomic status of these two types are discussed. This is the first report of molecular data about Paragonimus from Sri Lanka.     

Triterpenes of five euphorbiaceae species of Sri Lanka

Five endemic species of Euphorbiaceae have been investigated. Aleuritolic acid and its derivatives were isolated from P. thwaitesii. A. cardiosperma had friedelan derivatives. The Glochidion species contained the same triterpenes, viz. glochidonol, lup-20(29)-ene-3α,23-diol and glochidiol. The bark extractives of a new Glochidion species had, in addition, glochidone and probably lup-20(29)-ene-1α,3α,23-triol. The latter is a new natural product. Glochidone was isolated for the first time outside the genus Glochidion from Bridelia moonii.     

A new rhizomatous Oryza species (Poaceae) from Sri Lanka

VAUGHAN, D. A., 1990. A new rhizomatous Oryza species (Poaceae) from Sri Lanka. The confusing taxonomy of the Sri Lankan Oryza officinalis complex is clarified with the recognition of a new rhizomatous species, Oryza rhizomatis Vaughan. This species has been found across the dry zone. The other species of the complex in Sri Lanka, O. eichingeri , occurs in moist habitats and is smaller and less common than 0. rhizomatis. The new species is described.     

Xanthones and neoflavonoids from two asian species of calophyllum

The stem barks of both Calophyllum macrocarpum and C. walkeri have yielded the known neoflavonoid apetalic acid. In addition, C. walkeri bark gave four 1,3,7-oxygenated xanthones with prenyl substituents at C-2 and C-8. One of the xanthones has been identified as thwaitesixanthone, and the other three as the related novel derivatives thwaitesixanthonol, demethylcalabaxanthone and 2″-isopropenyl-3″-hydroxydihydrofuranodemethylcalabaxanthone.     

Pollen morphology of some selected plant species from Horton Plains,Sri Lanka

The pollen morphology of four species: Gaultheria leschenaultii (Ericaceae), Psychotria zeylanica (Rubiaceae), Rubus leucocarpus (Rosaceae) and Symplocos bractealis (Symplocaceae) from Horton Plains, Sri Lanka was investigated using LM and SEM. Psychotria zeylanica is endemic to Sri Lanka and the other three taxa are common in Horton Plains. Gaultheria leschenaultii has tetrads with 3-colporate, coarsely granular to granulo-rugulate pollen grains; in the polar region and at the colpus margin the exine is smooth with micro-rugulate structure. Psychotria zeylanica has 3- (or 4-) colporate, reticulate-spinulose to granular pollen grains. Rubus leucocarpus has 3-colporate, striate-perforate pollen grains and Symplocos bractealis has 3- (or 4-) colporate pollen grains with a verrucate-perforate exine. Pollen grains of these four species are very indicative of human impact and palaeoclimate.     

Two different begomovirus species are associated with yellow vein mosaic disease of okra in Sri Lanka

Molecular Biology Reports - Yellow vein mosaic disease is the major biotic constraint of okra cultivation in Sri Lanka. Identification and detailed molecular characterization of associated pathogen...     

Canine trypanosomosis in Sri Lanka: An emerging problem reported from three distinct geographic locations

Here we report three cases of canine trypanosomosis presented to the Veterinary Teaching Hospital in the Faculty of Veterinary Medicine and Animal Sciences at the University of Peradeniya, Sri Lanka during 2018. The cases were presented to the hospital when the dogs were already in critical condition. Confirmation of the cases was done by microscopic examination of Giemsa-stained thin blood smears. All three dogs had bilateral keratitis and anterior chamber cloudiness in eyes. Despite the intramuscular administration of diminazine aceturate, all of them subsequently died. Amplification and sequencing of a fragment of the internal transcribed spacer 1 (ITS1) of the nuclear ribosomal DNA confirmed the parasite as Trypanosoma. evansi. This is the first record of clinical cases of canine trypanosomosis in Sri Lanka. The three cases reported here came from widely separated geographical locations within the country: Balangoda, Mullaitivu and Kadawatha.     

A morphologically distinct Phlebotomus argentipes population from active cutaneous leishmaniasis foci in central Sri Lanka

Although the reported aetiological agent of cutaneous leishmaniasis (CL) in Sri Lanka is Leishmania donovani, the sandfly vector remains unknown. Ninety-five sandflies, 60 females and 35 males, collected in six localities in the district of Matale, central Sri Lanka, close to current active transmission foci of CL were examined for taxonomically relevant characteristics. Eleven diagnostic morphological characters for female sandflies were compared with measurements described for Indian and Sri Lankan sandflies, including the now recognised Phlebotomus argentipes sensu lato species complex. The mean morphometric measurements of collected female sandflies differed significantly from published values for P. argentipes morphospecies B, now re-identified as Phlebotomus annandalei from Delft Island and northern Sri Lanka, from recently re-identified P. argentipes s.s. sibling species and from Phlebotomus glaucus. Furthermore, analysis of underlying variation in the morphometric data through principal component analysis also illustrated differences between the population described herein and previously recognised members of the P. argentipes species complex. Collectively, these results suggest that a morphologically distinct population, perhaps most closely related to P. glaucus of the P. argentipess. I. species complex, exists in areas of active CL transmission. Thus, research is required to determine the ability of this population of flies to transmit cutaneous leishmaniasis.     

Reproductive biology of six Barbus species indigenous to Sri Lanka

Synopsis Six Barbus species were sampled monthly in two river systems of SW-Sri Lanka, over a 15 month period. Sex ratio, size at maturity, maximum and modal sizes, distribution of egg sizes in mature ovaries and individual fecundities were measured. Seasonal changes in size distributions, sex ratio, frequency of female gonadal stages and the gonado-somatic index (GSI) were analysed on the basis of the monthly samples. Seasonal cycles in reproductive activity were assessed, using mainly the two last-mentioned parameters and the appearance of young in the populations. It was found that three of the species (B. bimaculatus, B. cumingi, B. vittatus) tend to concentrate their reproductive activities in certain months of the year, roughly coinciding with the seasonal peaks of precipitation. The other three (B. nigrofasciatus, B. dorsalis, B. titteya) spread their reproductive efforts more evenly through the year. Sexual dimorphism with females bigger, relatively early maturation of males, high maximum GSI values, a distinct final mode of large mature ova in the egg-diameter distribution, and a comparatively steep increase of fecundity with body weight or gonad weight were found to be more or less consistently associated with seasonal reproduction.     

Upper pleistocene fossil hominids from Sri Lanka

Between 1978 and 1983 hominid skeletal remains were collected from the cave sites of Batadomba lena and Beli lena Kitulgala in Sri Lanka (formerly Ceylon). These are the most ancient specimens of anatomically modern Homo sapiens found thus far in South Asia, radiocarbon dates placing them in the Upper Pleistocene. Morphometric analysis of the remains of some 38 individuals from the two sites indicates that these populations were characterized by medium stature, moderate to pronounced cranial and postcranial robusticity, medium-size permanent tooth crown measurements, prognathic alveolar facial proportions, and low incidence of osseous and dental pathological conditions. Comparisons of these ancient Sri Lankans with other prehistoric skeletal series from South Asia and elsewhere support the hypothesis that muscular-skeletal robusticity was a significant physical adaptation of earlier hunting-foraging populations. A trend towards reduction of sexual dimorphism and development of more gracile body form and smaller teeth appears to have accelerated with the socioeconomic transition to food-production strategies involving agriculture and pastoralism and refinement of technologies for food procurement and preparation, as documented by morphometric studies of later prehistoric inhabitants of South Asia.     

Some lignicolous marine fungi from Sri Lanka

Koch, J. 1982. Some lignicolous marine fungi from Sri Lanka. – Nord. J. Bot. 2 : 163–169. Copenhagen. ISSN 0107–055X.
Twenty–seven marine fungi are reported from intertidal wood collected in the Indian Ocean at Sri Lanka. One new genus Nimbospora and two new species Nimbospora effusa and Halosarpheia bentotensis are described. A new combination Savoryella paucispora is proposed. Obervations are presented on some poorly known and interesting species.     

Record of five new endemic small mammal hosts for four ectoparasite species from Sri Lanka

Both ticks and fleas are medically important arthropods, which act as vectors for a number of zoonotic diseases. In Sri Lanka, 35 species of ticks and 20 species of fleas have been reported from mammals, birds and reptiles. However, records of these parasites from small mammals are scanty. Here, we report ticks and fleas infesting muroid rodents and shrews including endemic species collected from around the country. Of the 149 small mammals collected, 48 individuals were infested with ticks, fleas or both. Immature stages of three tick species, Ixodes ceylonensis, Haemaphysalis hystricis and Hyalomma brevipunctata and unidentified species of Rhipicephalus were recorded from ten small mammal species. Four species of fleas, Stivalius phoberus, Stivalius aporus, Lentistivalius ferinus and Nosopsyllus tamilanus were identified from five species of small mammals. We report new host species for I. ceylonensis (Crocidura miya, Suncus montanus and Solisorex pearsoni), S. aporus (S. montanus and Mus fernandoni), N. tamilanus (S. pearsoni) and Rhipicephalus spp. (Crocidura hikmiya, S. montanus, S. pearsoni, M. fernandoni). All new host species reported here are endangered or critically endangered endemics to Sri Lanka.     

A new genus and species of Urodidae (Lepidoptera: Urodoidea) from Sri Lanka

A new genus of Urodidae, Geoesthia gen. nov., is described with the type species, Geoesthia ceylonica sp. nov. from Sri Lanka. This is the second urodid genus from the Oriental Region. The new species is the only urodid recorded from Sri Lanka. The new genus is distinguished from all the known genera within Urodidae by a combination of four characteristics: the lack of scale tufts on the labial palpi; the absence of raised scales of two subbasal spots on the forewings; the presence of M-stem on the hindwings; and the female corpus bursae bearing five signa. Key to the genera and species of Urodidae from the Oriental Region is provided.     

Diversity of epicotyl dormancy among tropical montane forest species in Sri Lanka

• Fruiting season of many Sri Lankan tropical montane species is not synchronised and may not occur when conditions are favourable for seedling establishment. We hypothesised that species with different fruiting seasons have different seed dormancy mechanisms to synchronise timing of germination with a favourable season for establishment. Using six species with different fruiting seasons, we tested this hypothesis.
• Germination and imbibition of intact and manually scarified seeds were studied. Effect of GA₃ on germination was examined. Embryo length:seed length (E:S) ratio of freshly matured seeds and of those with a split seed coat was determined. Time taken for radicle and plumule emergence and morphological changes of the embryos were recorded.
• The radicle emerged from Ardisia missionis, Bheza nitidissima and Gaetnera walkeri seeds within 30 days, whereas it took >30 days in other species. Embryos grew in seeds of B. nitidissima and G. walkeri prior to radicle emergence but not in Microtropis wallichiana, Nothapodytes nimmoniana and Symplocos cochinchinensis. A considerable delay was observed between radicle and plumule emergence in all six species. Warm stratification and/or GA₃ promoted germination of all species.
• All the tested species have epicotyl dormancy. Seeds of B. nitidissima and G. walkeri have non‐deep simple morphophysiological epicotyl dormancy, and the other four species have non‐deep physiological epicotyl dormancy. Differences in radicle and epicotyl dormancy promote synchronisation of germination to a favourable time for seedling development. Therefore, information on dormancy‐breaking and germination requirements of both radicle and epicotyl are needed to determine the kind of dormancy of a particular species.

     

Two distinct isocitrate lyases from a pseudomonas species.

The isocitrate lyases of acetate- and methylamine-grown Pseudomonas MA (Shaw strain) were studied. They were shown to be different by a variety of physical criteria including chromatographic elution patterns, heat inactivation kinetics, pH variation of Km values, and migration on polyacrylamide gels. The implications and significance of the existence of two enzymes in relation to the role of isocitrate lyase in methylamine utilization is discussed.     

Karyosystematic studies onRubiaceae: Chromosome counts from Sri Lanka

Chromosome numbers for 16 different taxa ofRubiaceae from Sri Lanka are presented. Counts for 13 species, including 5 genera and 1 tribe, are new. The results are listed, compared with available literature data and discussed in regard to their systematical importance.     

Genus-level phylogeny of snakes reveals the origins of species richness in Sri Lanka

Snake diversity in the island of Sri Lanka is extremely high, hosting at least 89 inland (i.e., non-marine) snake species, of which at least 49 are endemic. This includes the endemic genera Aspidura, Balanophis, Cercaspis, Haplocercus, and Pseudotyphlops, which are of uncertain phylogenetic affinity. We present phylogenetic evidence from nuclear and mitochondrial loci showing the relationships of 40 snake species from Sri Lanka (22 endemics) to the remaining global snake fauna. To determine the phylogenetic placement of these species, we create a molecular dataset containing 10 genes for all global snake genera, while also sampling all available species for genera with endemic species occurring in Sri Lanka. Our sampling comprises five mitochondrial genes (12S, 16S, cyt-b, ND2, and ND4) and five nuclear genes (BDNF, c-mos, NT3 RAG-1, and RAG-2), for a total of up to 9582 bp per taxon. We find that the five endemic genera represent portions of four independent colonizations of Sri Lanka, with Cercaspis nested within Colubrinae, Balanophis in Natricinae, Pseudotyphlops in Uropeltidae, and that Aspidura + Haplocercus represents a distinct, ancient lineage within Natricinae. We synonymize two endemic genera that render other genera paraphyletic (Haplocercus with Aspidura, and Cercaspis with Lycodon), and discover that further endemic radiations may be present on the island, including a new taxon from the blindsnake family Typhlopidae, suggesting a large endemic radiation. Despite its small size relative to other islands such as New Guinea, Borneo, and Madagascar, Sri Lanka has one of the most phylogenetically diverse island snake faunas in the world, and more research is needed to characterize the island’s biodiversity, with numerous undescribed species in multiple lineages.     

Ephemeroptera of Sri Lanka: Ephemeridae

Abstract Two new species of Ephemera are described, Ephemera supposita Eaton is redescribed, and Rhoenanthus posticus Banks is transferred to Ephemera and redescribed. A key to the imagos of Ephemera from Sri Lanka is included.     

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.     

Isolation and molecular characterization of Toxoplasma gondii from chickens from Sri Lanka

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 100 free-range chickens (Gallus domesticus) from Sri Lanka was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT). Antibodies were found in 39 chickens with titers of 1:5 in 8, 1:10 in 8, 1:20 in 4, 1:40 in 5, 1:80 in 5, 1:160 in 5, 1:320 in 2, 1:640 or more in 2. Hearts and brains of 36 chickens with MAT titers of 1:5 or more were bioassayed in mice. Tissues of 3 chickens with doubtful titers of 1:5 were pooled and fed to a cat; the cat shed T. gondii oocysts in its feces. Tissues from 61 chickens with titers of less than 1:5 were pooled and fed to 2 T. gondii-free cats; the cats did not shed oocysts. Toxoplasma gondii was isolated from 11 of 36 seropositive chickens by bioassay in mice. All 12 T. gondii isolates were avirulent for mice. Genotyping of 12 isolates using the SAG2 locus indicated that 6 were type III, and 6 were type II. This is the first report of genetic characterization of T. gondii from any host in Sri Lanka.