共查询到20条相似文献,搜索用时 15 毫秒
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Tamal Mondal C. Raghunathan K. Venkataraman 《Proceedings of the Zoological Society》2014,67(2):136-139
Reefs of Andaman and Nicobar Islands harbour 418 species of scleractinian corals spread over an area of 2,000 km2. In April to May, 2010, due to the delayed onset of the southwest monsoon the sea surface temperature of the coastal and oceanic region increased to 31.7 °C in respect to the earlier record of maximum 29.0 °C during the said period. This resulted in mass bleaching of hermatypic corals during May, 2010. Rapid under water surveys have been conducted in reefs of Andaman and Nicobar Islands to assess the health of corals between May 2010 and August 2011. It is estimated that 76.62 ± (SD) 10.83 % of coral species are bleached up to a water depth of 10–15 m. Species from the genus Acropora appeared more susceptible to bleaching than those belong to the genus Porites. During the month of June 2010 the sea surface temperature was reduced to 29 °C perhaps due to the rainfall which stimulated rebuilding of zooxanthellae population in bleached corals. Recovery of 85.54 ± (SD) 6.33 % of bleached corals was seen during the study period of 11 months after the bleaching event. Porites spp. showed a high recovery rate, while Acropora spp. had the highest mortality rate. Coral mortality can have profound ecological and socio-economical implications and highlights the need for sustained monitoring for coral reef conservation in India. Hence, steps must be taken to improve management tools to protect these resources of global significance. 相似文献
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Bhattacharya D Bhattacharjee H Thamizhmani R Sayi DS Bharadwaj AP Singhania M Sugunan AP Roy S 《Letters in applied microbiology》2011,53(2):247-251
Aims: This study was carried out to find the prevalence of various plasmid‐mediated quinolone‐resistant (PMQR) determinants among the quinolone‐resistant clinical isolates of Shigella sp. from paediatric patients in Andaman & Nicobar Islands. Methods and Results: A total of 106 quinolone‐resistant Shigella isolates obtained from paediatric patients during hospital‐based surveillance from January 2003 to June 2010 were screened for the presence of various PMQR determinants. Of 106 isolates, 8 (7·5%) showed the presence of aac (6′)‐Ib‐cr and 3 (2·8%) harboured the qnrB genes with 2 (1·9%) of these isolates showing the presence of both. All the 9 isolates had uniform mutations in gyrA (S83L) and in parC (S80I). Conclusions: The prevalence of fluoroquinolone‐acetylating aminoglycoside acetyltransferase {aac (6′)‐Ib‐cr} gene is higher than qnrB gene among the clinical Shigella isolates. These PMQR determinants were detected in the Shigella isolates obtained from 2008–2010, indicating that it happens in a stepwise manner following the multiple mutations in quinolone resistance‐determining regions increase or extend resistance to quinolones or fluoroquinolones. Significance and Impact of Study: The prevalence of these genes are of grave concern as it may be horizontally transferred to other human pathogenic bacteria and can lead to therapeutic failure as a consequence of antimicrobial resistance, not only for the islands but also for the entire south‐east region. The results obtained should encourage further studies on the implications of the presence, distribution, association and variation of these determinants in our quest for understanding PMQR. 相似文献
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D. K. UPRETI A. SINGH 《Botanical journal of the Linnean Society. Linnean Society of London》1986,94(3):399-402
A new species of foliicolous lichens, Porina andamanensis , from the Andaman Islands, India, is described and illustrated. 相似文献
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Two new species, five new varieties and five new forms belonging to the desmid genera Closterium Nitzsch, Pleurotaenium Naeg., Euastridium W. & W., Micrasterias Agardh, Cosmarium Corda and Staurastrum Meyen from the Andaman Islands are described. 相似文献
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K M Murhekar M V Murhekar M B Mukherjee A C Gorakshakar R Surve M Wadia S Phanasgaonkar S Shridevi R B Colah D Mohanty 《Human biology; an international record of research》2001,73(5):739-744
The Great Andamanese are a primitive Negrito tribe of the Andaman and Nicobar Islands, India, with a total population of 37. We studied 29 individuals from eight families from this population for abnormal hemoglobins, G6PD deficiency, DNA haplotypes, and apolipoprotein B (APOB, gene) polymorphism. Hb E was detected in five individuals, the prevalence of Hb E heterozygotes being 14.3%. One individual had beta-thalassemia trait. One female was G6PD deficient and showed the G6PD Orissa mutation. Haplotype analysis of the beta-globin gene cluster showed that the betaE chromosomes were linked to two haplotypes (- - - - - + + and + + - + + + +) representing the framework 1 gene, whereas the betaA chromosomes showed eight different haplotypic patterns corresponding to framework 1 and 3 genes. APOB polymorphism analysis showed that the 631-base-pair (bp) allele was the predominant one with a high homozygosity rate, which could be due to the higher rate of inbreeding in this isolated group. The presence of Hb E and our findings on haplotype analysis supports the hypothesis that the Great Andamanese are reasonably believed to be the surviving representatives of the Negrito race that once flourished in the entire Southeast Asian region in ancient times. 相似文献
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D. K. UPRETI A. SINGH 《Botanical journal of the Linnean Society. Linnean Society of London》1987,94(3):399-402
A new species of foliicolous lichens, Porina andamanensis, from the Andaman Islands, India, is described and illustrated. 相似文献
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We surveyed the distribution and status of the long-tailed macaque (Macaca fascicularis umbrosa) in the Nicobar Islands of India. Long-tailed macaques live on 3 islands: Great Nicobar, Little Nicobar and Katchal. There are a total 788 groups. Group size ranged from 25 to 56 individuals with a mean size of 36. Long-tailed macaques are a multimale-multifemale society. Adult males, adult females and immatures constituted 9.7 per cent, 43.2 per cent and 47.1 per cent of the population, respectively. A fairly high ratio of immatures to adult females indicates a healthy population turnover. Vegetation parameters including tree density, canopy cover, canopy height and basal area indicated a still healthful habitats on all the 3 islands. We observed a few threats to the macaques. Measures should be undertaken to ensure survival of the Nicobar subspecies. 相似文献
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Avadhoot D. Velankar Honnavalli N. Kumara Arijit Pal Partha Sarathi Mishra Mewa Singh 《PloS one》2016,11(2)
Natural disasters pose a threat to isolated populations of species with restricted distributions, especially those inhabiting islands. The Nicobar long tailed macaque.Macaca fascicularis umbrosus, is one such species found in the three southernmost islands (viz. Great Nicobar, Little Nicobar and Katchal) of the Andaman and Nicobar archipelago, India. These islands were hit by a massive tsunami (Indian Ocean tsunami, 26 December 2004) after a 9.2 magnitude earthquake. Earlier studies [Umapathy et al. 2003; Sivakumar, 2004] reported a sharp decline in the population of M. f. umbrosus after thetsunami. We studied the distribution and population status of M. f. umbrosus on thethree Nicobar Islands and compared our results with those of the previous studies. We carried out trail surveys on existing paths and trails on three islands to get encounter rate as measure of abundance. We also checked the degree of inundation due to tsunami by using Normalized Difference Water Index (NDWI) on landsat imageries of the study area before and after tsunami. Theencounter rate of groups per kilometre of M. f. umbrosus in Great Nicobar, Little Nicobar and Katchal was 0.30, 0.35 and 0.48 respectively with the mean group size of 39 in Great Nicobar and 43 in Katchal following the tsunami. This was higher than that reported in the two earlier studies conducted before and after the tsunami. Post tsunami, there was a significant change in the proportion of adult males, adult females and immatures, but mean group size did not differ as compared to pre tsunami. The results show that population has recovered from a drastic decline caused by tsunami, but it cannot be ascertained whether it has reached stability because of the altered group structure. This study demonstrates the effect of natural disasters on island occurring species. 相似文献
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B. N. Singh 《Genetica》1986,69(2):143-147
In order to study the degree of genetic differentiation in natural populations of Drosophila ananassae, the mean genetic identity has been computed on the basis of differences in the gene arrangement frequencies. The estimates of genetic identity suggest that the populations from Keral, South India are genetically similar to the populations from the Andaman and Nicobar Islands though they are isolated by nearly 2 000 km of water. However, the South Indian populations are genetically more differentiated than the North Indian populations. 相似文献
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J. Santhanakumar R. Mohanraju R. Kirubagaran 《Invertebrate reproduction & development.》2014,58(2):128-137
Precopulatory mate guarding is a characteristic feature in the mating behaviour of many Malacostraca, and a necessary prerequisite for those species in which female receptivity for males is restricted to a short period of time after the pubertal/reproductive moult. This study deals with the pre-mate guarding behaviour of the semi-terrestrial isopod Ligia dentipes living in the crevices of coral boulders and rocks in the supralittoral region of the Andaman Islands. As in other isopods, moulting in L. dentipes is biphasic, in which the posterior body part invariably moults first. The guarding male aids the female partner in the removal of the moulted exoskeleton. Mating occurs immediately after the posterior body exuviates. The male leaves the female after copulation and goes in search of another receptive female, demonstrating a polygamous mating system in these isopods. The mated females also re-mate with several other males without mate guarding. Females that had mated several times produced more young, compared to females mated only once in the laboratory. Female receptivity ceases following moulting of the anterior half. Intrasexual encounters among males lead to the large males acquiring receptive females. This study reveals interesting deviations from the general pattern of mate guarding already reported in other isopods and decapods. The evolutionary and ecological significances of mate guarding, intrasexual and intersexual conflicts, found in these semi-terrestrial isopods, are discussed. 相似文献
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Host plant utilization by butterfly larvae in the Andaman and Nicobar Islands (Indian Ocean) 总被引:1,自引:0,他引:1
The larval food plants of the butterflies of the Andaman and Nicobar islands have not been studied, although the butterfly fauna per se is fairly well known. For the first time we report the food plants of the larvae of 120 species of butterflies from these islands on the basis of laboratory rearing and field studies. This information is essential for the formulation of management programmes for butterfly conservation on these islands which are known to harbour critical swallowtail and (possibly) danaine faunas. 相似文献
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Ragavan P. Kumar Sanjeev Kathiresan K. Mohan P. M. Jayaraj R. S. C. Ravichandaran K. Rana T. S. 《Hydrobiologia》2021,848(20):4673-4693
Hydrobiologia - The present study estimated plant biomass in mangrove forests of the Andaman Islands, India. The mean above-ground biomass was 469.20?±?41.25 Mega-gram/ha (Mg... 相似文献
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A new species Miliusa jainii (Annonaceae) from South Andamans, India, is described and illustrated. 相似文献
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P. S. N. Rao 《Nordic Journal of Botany》1992,12(2):227-229
A new species, Dendrobium gunnarii P. S. N. Rao, so far endemic to the virgin forests of Andaman Islands is described and illustrated. Affinities with the distantly related species D. wilmsianum Schltr. in section Stachyobium are dicussed. 相似文献
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A new species, Hydnocarpus sharmae (Flacourtiaceae) from North Andaman, India is described and illustrated. 相似文献
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