Lipid Biomarkers Reveal Microbial Communities in Hydrothermal Chimney Structures from the 49.6°E Hydrothermal Vent Field at the Southwest Indian Ocean Ridge

Lipid biomarkers were investigated to reveal the microbial life preserved in sulfide and Si-rich chimney from the 49.6°E hydrothermal vent field. In sulfide chimney, iso-/anteiso-fatty acids and H-shaped glycerol dialkyl glycerol tetraethers are the main microbial biomarkers. In Si-rich chimney, monounsaturated fatty acids (C16:1n7, C18:1n7) are the main bacterial biomarkers detected, and crenarchaeol and its isomer are relatively abundant (up to 25% of glycerol dialkyl glycerol tetraethers) archaeol biomarkers. Composition of lipid biomarkers reveals the diversity of microbial communities in different types of chimney structures. Sulfate-reducing bacteria and hyperthermophilic archaea were considered to be the majority microbial life in sulfide chimney, and sulfur-oxidizing bacteria were abundant in Si-rich chimney while archaea in Si-rich chimney and mainly attributed to Thaumarchaeota, which were predominately ammonia oxidizers. Our result suggested that fluid temperature and gaseous components could be the main constraints for the diversity of microbial communities in hydrothermal chimney structures in 49.6°E hydrothermal vent field.     

Discovery of new hydrothermal activity and chemosynthetic fauna on the Central Indian Ridge at 18°-20° S

Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called 'scaly-foot' gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean. Here we report two newly discovered hydrothermal vent fields, the Dodo and Solitaire fields, which are located in the Central Indian Ridge (CIR) segments 16 and 15, respectively. Chemosynthetic faunal communities at the Dodo field are emaciated in size and composition. In contrast, at the Solitaire field, we observed faunal communities that potentially contained almost all genera found at CIR hydrothermal environments to date, and even identified previously unreported taxa. Moreover, a new morphotype of 'scaly-foot' gastropod has been found at the Solitaire field. The newly discovered 'scaly-foot' gastropod has similar morphological and anatomical features to the previously reported type that inhabits the Kairei field, and both types of 'scaly-foot' gastropods genetically belong to the same species according to analyses of their COI gene and nuclear SSU rRNA gene sequences. However, the new morphotype completely lacks an iron-sulfide coating on the sclerites, which had been believed to be a novel feature restricted to 'scaly-foot' gastropods. Our new findings at the two newly discovered hydrothermal vent sites provide important insights into the biodiversity and biogeography of vent-endemic ecosystems in the Indian Ocean.     

A new species of Austrodecus Hodgson, 1907 (Arthropoda,Pycnogonida, Austrodecidae) from?the?Southwest Indian Ridge

A new species of pycnogonid collected by the Chinese research vessel R/V Dayangyihao during cruises to the Southwest Indian Ridge in 2008 and 2009 is recorded. The new species, Austrodecus bamberi, is placed into the tristanense-section by the characters of 4-articled ovigers and present auxiliary claws and is distinguished from other species in this section by the number and length of tubercles on the first coxae.     

Indian Science for Indian Tigers?: Conservation Biology and the Question of Cultural Values

The implementation of Project Tiger in India, 1973–1974, was justly hailed as a triumph of international environmental advocacy. It occurred as a growing number of conservation-oriented biologists were beginning to argue forcefully for scientifically managed conservation of species and ecosystems – the same scientists who would, by the mid-1980s, call themselves conservation biologists. Although India accepted international funds to implement Project Tiger, it strictly limited research posts to Government of India Foresters, against the protests of Indian and US biologists who hoped to conduct the scientific studies that would lead to better management and thus more effective conservation of the tiger. The foresters were not trained to conduct research, and in fact did not produce any of significance for the first 15 years of Project Tiger’s existence. The failure of biologists to gain access to India’s tigers in the 1970s was caused by many factors, but not least among them was a history of disdain among conservation-oriented biologists for government officials managing reserves, and the local politics of conservation. Project Tiger, then, serves as a case study for the discussion of the intersection of conservation biology with non-scientific concerns, including nationalism and the desire of the Indian government to more completely control its land.¹I would like to thank the participants in the 2003 Southwest Colloquium for the Life Sciences for their constructive comments on an earlier version of this paper, as well as the two unusually helpful (anonymous) reviewers.     

Hydrologic Modification and the Loss of Self-organized Patterning in the Ridge–Slough Mosaic of the Everglades

The ridge–slough landscape of the Everglades (Florida, USA), is characterized by elevated ridges dominated by sawgrass (Cladium jamaicense) interspersed among deeper sloughs dominated by floating, submerged and emergent macrophytes and calcareous periphyton. Interactions among hydrologic conditions (water depth, hydroperiod), plant composition and production, and respiration are hypothesized to create alternative peat accretion equilibria at the point scale, while spatial interactions among patches create regular pattern at the landscape scale. Despite significant research on these interactions, few studies have examined the hypothesis that the ridge–slough landscape consists of spatially coupled alternative stable patch states, and none has used diagnostic indicators thereof to assess landscape resilience to hydrologic change. Dense random sampling of water depths (a proxy for soil elevation) along a gradient of hydrologic impairment of drained to relatively natural to impounded conditions was used to evaluate four predictions related to this hypothesis: (1) bimodal soil elevation distributions show strong fidelity to community type; (2) positive autocorrelation at short distances with negative values at longer distances; (3) strong anisotropy (diagnostic of flow orientation), and spatial structure (diagnostic of the strength of landscape self-organization); and (4) loss of these features with hydrologic modification. Our results support the hypothesis that soil elevations are strongly bimodal and anisotropic in areas with minimal hydrologic impact, and spatial autocorrelation patterns indicate the operation of scale-dependent feedbacks. These metrics change markedly with hydrologic modification, although with differences between drainage and impoundment. Moreover, changes in landform precede associated changes in vegetation, suggesting their utility as diagnostic indicators of landscape degradation and recovery.     

Is the Narmada hominid an Indian Homo erectus?

In 1982 a fossil hominid calvaria was found in a middle Pleistocene deposit in the central Narmada valley of Madhya Pradesh, India, and was assigned to the new taxon Homo erectus narmadensis. Subsequently, morphometric studies of the specimen were conducted by two separate research teams from France and the United States, both in collaboration with Indian colleagues. Results of the most recent study, which includes morphometric and comparative investigations, lead to the conclusion that "Narmada Man" is appropriately identified as Homo sapiens. While the calvaria shares some anatomical features with Asian Homo erectus specimens, it exhibits a broader suite of morphological and mensural characteristics suggesting affinities with early Homo sapiens fossils from Asia, Europe, and Africa as well as demonstrating that the Narmada calvaria possesses some unique anatomical features, perhaps because the specimen reflects the incoherent classificatory condition of the genus Homo.     

Geographic limitations in the movement of Deep‐Draft tankers between the Indian and pacific oceans

Abstract

The need to move increasing volumes of petroleum over long distances has stimulated the construction of a large fleet of tankers of unprecedented dimensions. The extraordinarily deep drafts of these ships have necessitated a reevaluation of the extent of navigable ocean. Because some major shipping lanes are closed to their movement, alternative routes have developed. For this study, hydrographic charts of the passages between the Indian and Pacific oceans were examined in detail and special purpose maps were constructed. The patterns illustrate the categories of negative ocean, open ocean, and ocean conditional for the movement of deep‐draft ships. Actual and potential routeways for deep‐draft ships past Southeast Asia are identified and the limitations of the Malacca/Singapore straits are described in greater detail.     

Decline in seminal quality in Indian men over the last 37 years

Background

Since the first report of a decline in semen quality in 1974, there have been several reports of similar declines across populations. Despite some scattered reports of declining semen quality in the Indian sub-continent, comprehensive studies analyzing semen quality over the last few decades have not been undertaken. We undertook the present study to investigate the temporal trend in semen parameters in Indian populations over a period of 37 years (1979–2016).

Methods

Publications providing semen analysis details for fertile and infertile men from the Indian sub-continent were collected by a thorough literature search. Semen quality data for 6466 normal fertile or presumptive normal men (from 119 studies/data sets) and 7020 infertile men (from 63 studies/data sets) published between 1979 and 2016 were retrieved. We undertook systematic review and quantitative analysis of mean sperm count, motility, normal morphology and other available parameters. Data were analyzed to estimate semen parameters reference values for Indian men and to assess temporal trends in infertile, fertile and all subjects.

Results

Seminal quality shows a decreasing temporal trend and the decrease is higher in infertile than fertile males. In pooled analysis for all individuals, significant (p?<?0.05 or?<?0.001) declines in sperm concentration and normal morphology are observed; however, isolated analysis for each group shows declines without statistical significance. The mean (± SD) semen volume, sperm concentration, total motility, rapid linear progressive motility, normal sperm morphology and sperm viability for Indian fertile men are 2.88?±?0.77 ml, 81.08?±?29.21 million/ml, 66.37?±?10.95%, 52.64?±?15.78%, 56.68?±?20.23% and 72.63?±?8.31%, respectively, whereas in infertile these are 3.07?±?1.27 ml, 37.94?±?26.41 million/ml, 40.22?±?13.76%, 26.79?±?15.47%, 36.41?±?21.66% and 55.25?±?11.99%, respectively. The mean seminal parameter values were significantly lower (p?<?0.001) in infertile as compared to fertile men, except semen volume.

Conclusions

Semen parameters in Indian men have declined with time and the deterioration is quantitatively higher in the infertile group. The study also provides reference values for semen parameters in Indian men.

     

Biosignatures in chimney structures and sediment from the Loki’s Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge

We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki’s Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (δ³⁴S, ?³³S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 ‰ in δ³⁴S, and between 0.020 and 0.034 ‰ in Δ³³S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of ¹³C-depleted unsaturated and branched fatty acids with δ¹³C values between ?39.7 and ?26.7 ‰, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ¹³C values as low as ?46 ‰ also indicated the presence of methanogens and possibly methanotrophs.     

New Findings of the Rare Species Rondeletia bicolor (Stephanoberycoidei) Over the Mid-Atlantic Ridge and Some Peculiarities of the Rondeletiidae Family’s Phylologeny

Journal of Ichthyology - New morphometric data on the rare mesobathypelagic species Rondeletia bicolor (Rondeletiidae) caught over the central part of the Mid-Atlantic ridge in the depth range...     

Transmission Dynamics of Visceral Leishmaniasis in the Indian Subcontinent – A Systematic Literature Review

BackgroundAs Bangladesh, India and Nepal progress towards visceral leishmaniasis (VL) elimination, it is important to understand the role of asymptomatic Leishmania infection (ALI), VL treatment relapse and post kala-azar dermal leishmaniasis (PKDL) in transmission.

Methodology/ Principal Finding

We reviewed evidence systematically on ALI, relapse and PKDL. We searched multiple databases to include studies on burden, risk factors, biomarkers, natural history, and infectiveness of ALI, PKDL and relapse. After screening 292 papers, 98 were included covering the years 1942 through 2016. ALI, PKDL and relapse studies lacked a reference standard and appropriate biomarker. The prevalence of ALI was 4–17-fold that of VL. The risk of ALI was higher in VL case contacts. Most infections remained asymptomatic or resolved spontaneously. The proportion of ALI that progressed to VL disease within a year was 1.5–23%, and was higher amongst those with high antibody titres. The natural history of PKDL showed variability; 3.8–28.6% had no past history of VL treatment. The infectiveness of PKDL was 32–53%. The risk of VL relapse was higher with HIV co-infection. Modelling studies predicted a range of scenarios. One model predicted VL elimination was unlikely in the long term with early diagnosis. Another model estimated that ALI contributed to 82% of the overall transmission, VL to 10% and PKDL to 8%. Another model predicted that VL cases were the main driver for transmission. Different models predicted VL elimination if the sandfly density was reduced by 67% by killing the sandfly or by 79% by reducing their breeding sites, or with 4–6y of optimal IRS or 10y of sub-optimal IRS and only in low endemic setting.

Conclusion/ Significance

There is a need for xenodiagnostic and longitudinal studies to understand the potential of ALI and PKDL as reservoirs of infection.     

Population differentiation or species formation across the Indian and the Pacific Oceans? An example from the brooding marine hydrozoan Macrorhynchia phoenicea

Assessing population connectivity is necessary to construct effective marine protected areas. This connectivity depends, among other parameters, inherently on species dispersal capacities. Isolation by distance (IBD ) is one of the main modes of differentiation in marine species, above all in species presenting low dispersal abilities. This study reports the genetic structuring in the tropical hydrozoan Macrorhynchia phoenicea α (sensu Postaire et al ., 2016a), a brooding species, from 30 sampling sites in the Western Indian Ocean and the Tropical Southwestern Pacific, using 15 microsatellite loci. At the local scale, genet dispersal relied on asexual propagation at short distance, which was not found at larger scales. Considering one representative per clone, significant positive F _IS values (from ?0.327*** to 0.411***) were found within almost all sites. Gene flow was extremely low at all spatial scales, among sites within islands (<10 km distance) and among islands (100 to >11,000 km distance), with significant pairwise F _ST values (from 0.035*** to 0.645***). A general pattern of IBD was found at the Indo‐Pacific scale, but also within ecoregions in the Western Indian Ocean province. Clustering and network analyses identified each island as a potential independent population, while analysis of molecular variance indicated that population genetic differentiation was significant at small (within island) and intermediate (among islands within province) spatial scales. As shown by this species, a brooding life cycle might be corollary of the high population differentiation found in some coastal marine species, thwarting regular dispersal at distances more than a few kilometers and probably leading to high cryptic diversity, each island housing independent evolutionary lineages.     

Impacts of the 2014–2017 global bleaching event on a protected remote atoll in the Western Indian Ocean

Coral Reefs - The third global bleaching event caused prolonged elevated sea surface temperatures from 2014 to 2017 that heavily impacted coral reefs worldwide. This study determines changes in...     

The myth of “minima” and “maxima”, the species of Physalis in the Indian Subcontinent

The status of the names, Physalis minima L. and P. maxima Mill. (Solanaceae), and their alleged presence on the Indian subcontinent are discussed. The issues of nativity and identity of Linnaean Physalis minima are long-debated while the use of the name P. maxima Mill. and its report from India are recent. The available evidence indicates that the name “P. minima L.” is misapplied to two different elements, viz., P. angulata L. and P. lagascae Roem. & Schult. The name Physalis minima L. may be rejected as nomen confusum, for which the paper provides the primary information. As on today, it is submerged under the synonymy of P. angulata L. The correct name for the widely known P. minima is P. lagascae. The name “P. maxima Mill.” applied to the escape and naturalized weed in the Indian subcontinent and elsewhere is to be substituted by P. pruinosa L., a name misapplied to P. grisea (Waterf.) M. Martínez.