Remarkable genetic homogeneity in unstriped, long-tailed Ichthyophis along 1500 km of the Western Ghats, India

The mountainous Western Ghats are part of a biodiversity hotspot and extend for about 1600 km, lying close and subparallel to the west coast of peninsular India. The region is a centre of diversity for amphibians, and recent preliminary work on some components of both caecilian (Gymnophiona) and frog (Anura) fauna is indicative of a high degree of local endemism. We investigated diversity in mitochondrial rRNA 12S and 16S sequences for long-tailed, unstriped Ichthyophis (Amphibia: Gymnophiona: Ichthyophiidae) that potentially represent four taxonomically confused and poorly known endemic caecilian species. Data were analysed for18 individuals from along c . 1500 km of the Western Ghats region. Genetic diversity is remarkably low, with a maximum uncorrected p -distance of 0.5%. These DNA sequences and new morphological data do not allow us to reject the null hypothesis that the sample comprises only a single, widely distributed, highly interconnected species. The phylogenetic signal among the data is extremely low. However, population genetic analyses reveal that the Palghat Gap, a c . 30 km discontinuity in the Western Ghats considered to be significant in the biogeography of other organisms occurring in this region, corresponds to a significant subdivision of long-tailed, unstriped Ichthyophis into two groups.     

Molecular systematics of caeciliid caecilians (Amphibia: Gymnophiona) of the Western Ghats, India

Together, Indian plus Seychelles caeciliid caecilian amphibians (Gymnophiona) constitute approximately 10% of the extant species of this order. A molecular phylogenetic analysis of all but one (or two) nominal species (16, in five genera) is presented based on mitochondrial (12S, 16S, cytb, cox1) and nuclear (RAG1) sequence data. Results strongly support monophyly of both Seychelles and peninsular Indian caeciliids, and their sister-group status. Within the Indian caeciliids, Indotyphlus and Gegeneophis are monophyletic sister genera. The phylogenetic position of Gegeneophis ramaswamii, Gegeneophis seshachari, and Gegeneophis carnosus are not well resolved, but all lie outside a well-supported clade of most northern Western Ghats Gegeneophis (madhavai, mhadeiensis, goaensis, danieli/nadkarnii). Most nominal species of Indian caeciliid are diagnosed by robust haplotype clades, though the systematics of G. carnosus-like forms in northern Kerala and southern Karnataka requires substantial further investigation. For the most part, Indian caeciliid species comprise narrowly distributed, allopatric taxa with low genetic diversity. Much greater geographic genetic diversity exists among populations referred to G. seshachari, such that some populations likely represent undescribed species. This, the first phylogenetic analysis of Indian caeciliids, generally provides additional support for recent increases in described species (eight since 1999), and a framework for ongoing taxonomic revision.     

Assemblage structure of stream fishes in the Western Ghats (India)

Macro and microhabitat analyses were applied to characterise the fish assemblage structure in 10 streams of the Western Ghat mountains of Peninsular India. Macrohabitat features, such as channel gradient, stream depth, stream width, riparian cover, instream cover, habitat types and substrates, were used. Microhabitat requirements of the abundant cyprinids (35 species) were also analysed. Macrohabitat assessment indicated that a high habitat diversity was associated with a high species diversity, and that habitat volume was a major determining factor for species diversity and abundance. In all streams, cyprinids were the dominant group in the assemblage and almost all cyprinids were confined to pools with a varied habitat diversity. Riffle dwelling species included ancient forms such as Glyptothorax madraspatnum, G. trewasae and Homaloptera santhamparaiensis. Suitable microhabitats for dominant cyprinid species were pools and riffle edges. Big-sized barbs and mahseers such as Hypselobarbus dobsoni, H. curmuca, H. dubius, Labeo calbasu, Puntius sarana, Tor khudree and Tor khudree malabaricus were confined to deep pools with a large area. Smaller Puntius species like P. fasciatus, P. melanampyx, P. narayani, P. sophore, P. ticto and P. vittatus lived in shallow backwater pools and pools with low flow. Species like P. arulius tambiraparniei, P. amphibius, P. bimaculatus and P. filamentosus were found towards shallow pools with moderate flow. Surface-dwelling species such as Danio aequipinnatus, Rasbora daniconius, Salmostoma spp. and Barilius spp. preferred deepwater habitats with high flow. Habitat-based multivariate analysis revealed four guilds: surface dwellers, column dwellers, generalized bottom dwellers and specialized bottom dwellers.     

A new species of Cycas from the Malabar Coast, Western Ghats, India

A new cycad species,Cycas annaikalensis, has been discovered from the Malabar Coast of the southern Western Ghats of India. Although geographically distributed in a small population within the range ofC. circinalis, it can be distinguished from the other described IndianCycas species by its distinct habitat, habit, morphology of vegetative and reproductive parts, and anatomy of leaflets.     

A new iridescent tarantula of the genus Thrigmopoeus Pocock, 1899 from Western Ghats,India

A distinctive new species of ground burrowing tarantula from Western Ghats endemic genus Thrigmopoeus is described from Kerala State, India. Thrigmopoeus psychedelicus sp. nov. differs from putative species of the genus in the adults being black overall with a metallic blue lustre on the carapace and abdomen. Females of Thrigmopoeus psychedelicus sp. nov. exhibit polychromatism. Juveniles and sub-adults are paler with vibrant maroon colouration on its abdomen whereas adult females are much darker and lack vibrant colouration as sub-adults.     

Agni's fungi: heat-resistant spores from the Western Ghats, southern India

This study concerns the thermotolerance of spores of mesophilic fungi isolated from a tropical semi-arid habitat subject to dry season fire in the Western Ghats, southern India. Among 25 species of Ascomycota isolated from leaf litter, nine were able to grow after incubation in a drying oven for 2h at 100°C; the spores of two of these species survived 2h incubation at 110°C, and one survived exposure to 115°C for 2h. The range of thermotolerance among mesophilic fungi isolated from the leaf litter was surprising: filamentous fungi from other habitats, including species that colonize scorched vegetation after fires and thermophilic forms occurring in self-heating plant composts, cannot survive even brief exposure to such high temperatures. It is possible that the exceptional heat resistance of the Indian fungi is related to adaptations to surviving fires. Genetic analysis of the physiological mechanisms of heat resistance in these fungi offers prospects for future biotechnological innovations. The discovery of extreme thermotolerance among common saprotrophs shows that this physiological trait may be more widespread than recognized previously, adding to concern about the evolution of opportunistic pathogens on a warmer planet. The fungi in this study are among the most heat-resistant eukaryotes on record and are referred to here as 'Agni's Fungi', after the Hindu God of Fire.     

Arbuscular mycorrhizas of plants growing in the Western Ghats region, Southern India

A survey of the arbuscular mycorrhizal (AM) status of plants growing in the Western Ghats region of Southern India was undertaken. Root and soil samples of plants growing in the four vegetation types forest, grassland, scrub, and cultivated land or plantation were examined. Of the 329 species (representing 61 families) examined, 174 were mycorrhizal. AM association was recorded in 81 species for the first time, including species from several families assumed to be non-mycorrhizal, e.g. Amaranthaceae, Capparaceae, Commelinaceae, Cyperaceae and Portulacaceae. AM fungal spores of 35 species belonging to Acaulospora, Gigaspora, Glomus, Sclerocystis and Scutellospora were recorded. AM fungal species richness was found to be highest in scrub and lowest in agricultural and plantation soils. Mean colonization levels were dependent on plant life-form, life-cycle pattern and vegetation type. Accepted: 26 October 1999     

Patterns in the distribution of freshwater fishes in rivers of Central Western Ghats, India and their associations with environmental gradients

The community ecology of freshwater fishes in four river systems (Sharavati, Aghanashini, Bedti and Kali) of the central Western Ghats (India) has been studied for the first time. Patterns of fish species distributions were analysed and important stream and environmental parameters determining the species richness and composition of this region were identified. Upstream--downstream trends in species richness and diversity as well as changes in stream characteristics were studied using univariate correlation analyses. Preliminary analyses on changes in species composition and feeding guilds showed the presence of a gradual species turnover along the stream gradient. There were associated changes in the major feeding guild compositions, with a higher proportion of insectivore and algivore/herbivore composition in the upper reaches shifting to a predominance of omnivores and carnivores downstream. Pearsons product--moment correlation analyses along with stepwise multiple regression analyses identified stream depth and altitude as the important parameters determining species richness. Canonical correspondence analysis was performed to study species associations with environmental parameters. The analysis showed a strong species environmental correlation to the CCA axes, a high significance for the CCA axis 1 as well as for the overall test. The plots of the species and site scores on the CCA axes showed a clear segregation of species based on their relations with environmental and stream properties. This study is an important step in our understanding of the community structure of fish species of these rivers and would be helpful in future efforts on the conservation of aquatic communities and their habitats.     

Landscape ecology and conservation of birds in the Western Ghats, South India

The principle of landscape ecology finds wide application in conservation of biodiversity in fragmented and Man altered landscapes. Protection of carefully chosen habitats, networked by appropriate corridors can considerably enhance local biodiversity, especially outside major protected areas. This paper discusses the landscape ecology approach to the conservation of birds in a south India hill district. By the protection of 5 of the 21 major habitats spread over 18 localities, 76% of the district's avifauna can be conserved and protected.     

Studies on the aquatic hyphomycetes of a sulfur spring in the Western Ghats, India

Studies on the occurrence of aquatic hyphomycetes were carried out in Panekal sulfur spring in the Western Ghats, India by incubation of leaf litter and analysis of natural foam and of induced foam. Sampling was done once every three months over a period of two years from September 1989 to June 1991. The temperature, pH, dissolved oxygen, and sulfide content of water were also measured. No fungi were observed within the spring, whereas 16 species belonging to 13 genera were isolated from two outflow sites of the stream. The percent frequency of Triscelophorus monosporus was high (24.0%). The temperature of water in the spring ranged between 30.0 and 38.5°C and the sulfide content between 3.2 and 4.3 mg 1^–1. Studies showed that sulfide water (4.0 mg 1^–1). from the spring inhibited the growth of the colonies of Dactylella aquatica, Phalangispora constricta, Tetracladium setigerum, Vermispora cauveriana, and Wiesneriomyces laurinus. When the leaves colonized by aquatic hyphomycetes were incubated at different temperatures in sulfur-spring water and stream water separately, sporulation was not observed in any of the fungi at and above 35°C except Phalangispora constricta, which could sporulate at 35°C. At lower temperatures (15–30°C) relatively fewer species were found to sporulate in sulfur-spring water than in stream water. Correspondence to: K.M. Kaveriappa     

Drivers of reptile and amphibian assemblages outside the protected areas of Western Ghats,India

Biodiversity conservation in forested landscapes outside protected areas is important to sustain populations of species with restricted ranges. However, such habitats face many anthropogenic threats, including logging, extraction of firewood and leaf-litter for mulch in plantations. In this study, we determined the effects of forest degradation on amphibians and reptiles in forests outside protected areas by measuring their species richness and community composition across a disturbance gradient from near pristine to highly degraded forests in Agumbe, Western Ghats, India. Twenty-one strip 15 m × 150 m transects were laid across the disturbance gradient and diurnal visual encounter surveys were conducted. Sampling was repeated three times per transect covering the dry, intermediate and wet seasons. Amphibian and reptile communities were affected by the decrease in canopy cover and leaf litter volume, respectively. Our results indicate that the collection of firewood and leaf-litter can severely affect amphibian and reptile populations. Structured conservation planning outside of protected areas is therefore imperative.     

Patterns of species discovery in the Western Ghats,a megadiversity hot spot in India

Even since Linnaeus, naturalists and taxonomists have been systematically describing species new to science. Besides indicating gaps in taxonomic effort, understanding the temporal patterns of species discovery could help in identifying drivers that determine discovery. In this study we report the patterns of discovery of eight taxa — birds, butterflies, frogs, tiger beetles, grasses, asters, ferns and orchids — in the Western Ghats, a megadiversity centre in India. Our results indicate that the discovery curves for birds and butterflies have been saturated while those for frogs and grasses continue to increase. Within each taxon, the major drivers of discovery were commonness of the species and their size. The average years taken for discovery across taxa were directly related to the per cent endemicity and species richness of the taxa. We discuss the trajectories of discovery with respect to rarity or endemicity of the species and life history features, and the implications these might have for strategizing the discovery process in India.     

Spatial distribution of nematode genera in relation to host plants of Western Ghats,Tamil Nadu,India

A survey of plant parasitic nematodes (PPN) abundance and diversity was conducted in foothills of Western Ghats at Coimbatore and Nilgiris districts in Tamil Nadu, India. Our study pointed to evaluate the PPN association with weeds, shrubs, and herbs including some agricultural crop cover both agro and forest ecosystems. Soil samples were collected around the rhizosphere of the plants and nematodes were isolated, counted under a microscope and identified by morphological characters. We collected 415 soil samples around the rhizosphere of 84 major plant families. Among 84 plant families, we found 13 PPN genera those generally responsible for cash crop yield loss. The genus Helicotylenchus spp., and Meloidogyne spp., were found frequent (226,136 samples) and rarely Hemicycliophora spp.,. The PPN diversity was measured by Shannon diversity index which showed that the diversity of PPN found higher in plant species those from the families Rosaceae (2.20) and Rubiaceae (2.13). We also recorded the PPN richness was dominated in four plant families. This result reveals that the PPN diversity and richness are positively correlated with host plant species diversity and altitude. Further, our study concludes that a wild plant in the forest ecosystem behaves like a reservoir of PPN.     

Ethnomedicinal assessment of Irula tribes of Walayar valley of Southern Western Ghats,India

The present study was aimed to explore the traditional knowledge of Irula tribal people who are practicing herbal medicine in Walayar valley, the Southern Western Ghats, India. A total number of 146 species of plants distributed in 122 genera belonging to 58 families were identified as commonly used ethnomedicinal plants by them. Interestingly, 26 new claims were also made in the present study. Through the data obtained from Irula tribal healers, the herbs were mostly used for medicine (40.4%) followed by trees (26.7%) and climbers (18.5%). In addition leaves were highly used for medicinal purposes, collected from 55 species (38%) followed by multiple parts from 18 species (12%). Acorus calamus is the species of higher use value (1.80) assessed to be prescribed most commonly for the treatment of cough. High informant consensus factor (1.0) obtained for insecticidal uses and cooling agent indicates that the usage of Canarium strictum and Melia dubia, and Mimosa pudica and Sesamum indicum respectively for that purposes had obtained high degree of agreement among the healers in using these species for the respective purposes. The most commonly used method of preparation was decoction (63%) followed by raw form (23%), paste (12%) and powder (2%). Therefore, it is suggested to take-up pharmacological and phytochemical studies to evaluate the species to confirm the traditional knowledge of Irulas on medicinal plants.     

Occurrence of Gluconacetobacter diazotrophicus in tropical and subtropical plants of Western Ghats, India

Endophytic bacteria were isolated from the tissues of surface sterilized roots, stems, and leaves of fifty different crop plants. Phenotypic, biochemical tests and species-specific PCR assay permitted identification of four isolates of Gluconacetobacter diazotrophicus from root tissues of carrot (Daucus carota L.), raddish (Raphanus sativus L.), beetroot (Beta vulgaris L.) and coffee (Coffea arabica L.). Further the plant growth promoting traits such as nitrogenase activity, production of phytohormone indole acetic acid (IAA), phosphorus and zinc solubilization were assessed. Significant nitrogenase activity was recorded among the isolates and all the isolates produced IAA in the presence of tryptophan. Though all the four isolates efficiently solubilized phosphorus, the zinc solubilizing ability differed among the isolates.     

Diversity of Bacillus thuringiensis Isolated from Western Ghats of Tamil Nadu State, India

The Western Ghats of India is the one of the world’s 10 “Hottest biodiversity hotspots” that runs along the western part of India through four states including Tamil Nadu. The only biodiversity reserve in the Western Ghats is the Nilgiri biosphere located in the Tamil Nadu state. In the present study, 525 soil samples were collected from all the 14 different divisions of the Western Ghats in Tamil Nadu state, India. A total of 316 new isolates of Bacillus thuringiensis (Bt) that produce parasporal crystalline inclusions were isolated from 525 soil samples. Seven different types of crystalline inclusions were observed in the 316 new isolates of Bt. Cuboidal inclusion was predominantly present in 26.9% of the Bt isolates when compared to other shapes. Further characterization of 70 of the 316 Bt isolates for crystal protein profile through SDS-PAGE revealed six different types of crystal protein profile viz., 135 and 65, 135, 95, 65, 43, and 30 kDa crystal proteins. Variation in the mass of crystal protein(s) purified from the isolates of Bt revealed molecular diversity of this bacterium prevalent in the Western Ghats of Tamil Nadu, India.