Life Sciences Commons^™

Hers And His: Silk Glands Used In Egg Sac Construction By Female Spiders Potentially Repurposed By A 'Modern' Male Spider, Mark A. Townley, Danilo Harms

Biological Sciences

Cylindrical silk gland (CY) spigots distinguish a large clade of modern spiders, the CY spigot clade, which includes all entelegyne spiders and their closest relatives. Following a widespread paradigm, CYs and their spigots are only known to occur in female spiders and they produce silk used in the construction of egg sacs. Here we report the occurrence of a CY spigot or CY nubbin on each posterior median spinneret (PMS) in males (5th stadium and later) of the spider Australomimetus maculosus. Late juvenile males had a CY spigot on each PMS, whereas adult males either had a CY spigot or, …

Heavy Metal Dissolution Mechanisms From Electrical Industrial Sludge, Viraj Gunarathne, Anushka Upamali Rajapaksha, Meththika Vithanage, Nadeesh Adassooriya, Asitha Cooray, Sudantha Liyanage, Bandunee Athapattu, Nishanta Rajakaruna, Avanthi Deshani Igalavithana, Deyi Hou, Daniel S. Alessi, Yong Sik Ok

Biological Sciences

In this paper, we investigate the release of heavy metals from sludge produced from an electrical industry using both organic and inorganic acids. Single and sequential extractions were conducted to assess heavy metals in different phases of the sludge. Metal release from sludge was investigated in the presence of three inorganic acids (nitric, sulfuric, and phosphoric) and three organic acids (acetic, malic, and citric) at concentrations ranging from 0.1 to 2.0 mol L−1. Sequential extraction indicated the presence of Cu primarily in the carbonate fraction, Pb in the residual fraction, and Ni in the FeMn oxide fraction. The cumulative release …

Heavy Metal-Induced Oxidative Stress On Seed Germination And Seedling Development: A Critical Review, Mihiri Seneviratne, Nishanta Rajakaruna, Muhammad Rizwan, H. M. S. P. Madawala, Yong Sik Ok, Meththika Vithanage

Biological Sciences

Heavy metal contamination in soils can influence plants and animals, often leading to toxicosis. Heavy metals can impact various biochemical processes in plants, including enzyme and antioxidant production, protein mobilization and photosynthesis. Hydrolyzing enzymes play a major role in seed germination. Enzymes such as acid phosphatases, proteases and α-amylases are known to facilitate both seed germination and seedling growth via mobilizing nutrients in the endosperm. In the presence of heavy metals, starch is immobilized and nutrient sources become limited. Moreover, a reduction in proteolytic enzyme activity and an increase in protein and amino acid content can be observed under heavy …

The Effects Of Edaphic And Climatic Factors On Secondary Lichen Chemistry: A Case Study Using Saxicolous Lichens, Alexander Paukov, Anzhelika Teptina, Maria Morozova, Ekaterina Kruglova, Sergio E. Favero-Longo, Cora Bishop, Nishanti Rajakaruna

Biological Sciences

Diversity of secondary lichen metabolites and their relationship to substrate and environmental parameters were studied in saxicolous lichens in the Middle and South Urals of Russia. Atranorin, usnic acid, gyrophoric acid, zeorin, norstictic acid, antraquinones and stictic acid were found in 73, 42, 41, 37, 36, 35 and 32 species, respectively, of 543 taxa collected. One hundred and ninety six species (i.e., 36% of total species documented) contained no secondary metabolites. Spectra of secondary metabolites of crustose lichens varied on different rock types, while in fruticose and foliose groups only those species without lichen acids were dependent on the substrate …

Tropic Transfer And Bioaccumulation Of Lead Along Soil-Plant-Aphid-Ladybird Food Chain, Mohod Irfan Naikoo, Mudasir Ifran Dar, Fareed Ahmad Khan, Fariha Raghib, N. Rajakaruna

Biological Sciences

Lead (Pb) contamination of agroecosystems is a serious issue as Pb is a persistent pollutant that is retained in soil for long, causing toxicities to organisms. This study examines biotransfer of Pb from soils treated with different concentrations of Pb through a broad bean (Vicia faba L.)–aphid (Aphis fabae Scop.)–ladybird (Coccinella transversalis Fabricius) food chain and its consequent inference for natural biological control, the ladybird. The soil was amended with Pb at the rates of 0, 25, 50, 75 and 100 mg kg⁻¹(w/w). The amount of Pb in plant, aphid and ladybird increased in a dose-dependent manner …

Influence Of Soil Water Content And Soil Amendments On Trace Metal Release And Seedling Growth In Serpentine Soil, Viraj Gunarathne, Nishanta Rajakaruna, Udaya Gunarathne, Jayanta Kumar Biswas, Zach A. Raposo, Meththika Vithanage

Biological Sciences

This study was conducted to evaluate the synergistic effects of organic amendments and soil water status on trace metal release from serpentine soil.

From Spinning Silk To Spreading Saliva: Mouthpart Remodeling In Manduca Sexta (Lepidoptera: Sphingidae), Istvan Miko, Sarthok Rasique Rahman, Anne C. Jones, Mark A. Townley, Brandon Gominho, Sulav Paudel, S David Stupski, Heather M. Hines, Rudolf J. Schilder

Biological Sciences

As a model organism, the tobacco hornworm Manduca sexta (Linnaeus 1763) has contributed much to our knowledge of developmental processes in insects, and major developmental changes between different larval instars are generally well understood. Second and later instars of M. sexta do not produce silk, and their spinneret and accessory labial glands (=Lyonet’s glands), structures thought to be key players in silk production in other lepidopterans, are highly reduced. To our knowledge, mouthparts and labial gland morphology of the silk-producing first instar have never been described. In this study, we compared the mouthpart morphology and transcriptome profile of first and …

Long-Term Phytoremediating Abilities Of Dalbergia Sissoo Roxb. (Fabaceae), Saqib Ul Kalam, Fauzia Naushin, Fareed Ahmad Khan, Nishanta Rajakaruna

Biological Sciences

The boom of tanneries in north India has converted the river Ganga into a waste dumping stream. The tanneries discharge their heavy metal-rich effluents into the river. Tissues of two-year-old tree saplings of Dalbergia sissoo, soil sediments and river water samples were collected from three sites along the river Ganga at Jajmau, Kanpur. Site-1 was located 1 km upstream from the point of discharge of the effluents of the tanneries, Site-2 was close to the source point, and Site-3 was about 1 km downstream from the source point. Accumulation of Cu, Cr and Ni in leaves, bark, wood growth rings, …

Climactic Niche Model For Overwintering Monarch Butterflies In A Topographically Complex Region Of California, Ashley Fisher, Kiana Saniee, Charis Van Der Heide, Jessica Griffiths, Daniel Meade, Francis X. Villablanca

Biological Sciences

We use climatic conditions that are associated with known monarch butterfly overwintering groves in California to build a Maxent model, and focus on the fine scale probability of overwintering grove occurrence in a topographically complex region of the state (Santa Barbara County). Grove locations are known from recent and historical surveys and a long-term citizen science database. The climatic niche model performs well, predicting that overwintering habitat is most likely to occur along the coast and at low elevations, as shown by empirical data. We then use climatic variables in conjunction with climate change scenarios to model the future location …

Intracanopy Adjustment Of Leaf-Level Thermal Tolerance Is Associated With Microclimatic Variation Across The Canopy Of A Desert Tree (Acacia Papyrocarpa), Ellen M. Curtis, Charles A. Knight, Andrea Leigh

Biological Sciences

Tree crowns are spatially heterogeneous, sometimes resulting in significant variation in microclimate across the canopy, particularly with respect to temperature. Yet it is not known whether such localised temperature variation equates to intracanopy variation in leaf-level physiological thermal tolerance. Here, we studied whether microclimate variation across the canopy of a dominant desert tree equated to localised variation in leaf thermal thresholds (T₅₀) among four canopy positions: upper south, upper north, lower south, lower north. Principal component analysis was used to generate a composite climatic stress variable (C_STRESS) from canopy temperature, vapour pressure deficit, and …

Inducing Ni Sensitivity In The Ni Hyperaccumulator Plant Alyssum Inflatum Nyárády (Brassicaceae) By Transforming With Cax1, A Vacuolar Membrane Calcium Transporter, Rasoul Ghasemi, Hoorieh Share, Roza Sharif, Robert S. Boyd, Nishanta Rajakaruna

Biological Sciences

The importance of calcium in nickel tolerance was studied in the nickel hyperaccumulator plant Alyssum inflatum by gene transformation of CAX1, a vacuolar membrane transporter that reduces cytosolic calcium. CAX1 from Arabidopsis thaliana with a CaMV35S promoter accompanying a kanamycin resistance gene was transferred into A. inflatum using Agrobacterium tumefaciens. Transformed calli were subcultured three times on kanamycin-rich media and transformation was confirmed by PCR using a specific primer for CAX1. At least 10 callus lines were used as a pool of transformed material. Both transformed and untransformed calli were treated with varying concentrations of either calcium (1–15 mM) or …

Biological Crusts Of Serpentine And Non-Serpentine Soils From The Barberton Greenstone Belt Of South Africa, Arthurita Venter, Stefan Siebert, Nishanta Rajakaruna, Sandra Barnard, Anatoliy Levanets, Arshad Ismail, Mushal Allam, Bianca Peterson, Tomasz Sanko

Biological Sciences

Climate and geography can influence biological soil crust (BSC) community composition, but local heterogeneity in variables such as soil characteristics or microclimate gradients can also impact cryptogamic diversity. Heavy metals and nutrient imbalances in serpentine soils are known to influence the distributions of higher plants, but cryptogamic species appear to be more tolerant of substrate. The aim of this study was to compare the cryptogamic composition of serpentine and non-serpentine soils by using integrative taxonomy, which combines morphological and DNA barcoding data, to determine how soil characteristics in combination with rainfall can influence BSC community composition. Samples from serpentine and …

Senecio Conrathii N.E.Br. (Asteraceae), A New Hyperaccumulator Of Nickel From Serpentinite Outcrops Of The Barberton Greenstone Belt, South Africa, Stefan Siebert, Nadine Carol Schutte, Stoffel Pieter Bester, Dennis Mmakgabo Komape, Nishanta Rajakaruna

Biological Sciences

Five nickel hyperaccumulators belonging to the Asteraceae are known from ultramafic outcrops in South Africa. Phytoremediation applications of the known hyperaccumulators in the Asteraceae, such as the indigenous Berkheya coddii Roessler, are well reported and necessitate further exploration to find additional species with such traits. This study targeted the most frequently occurring species of the Asteraceae on eight randomly selected serpentinite outcrops of the Barberton Greenstone Belt. Twenty species were sampled, including 12 that were tested for nickel accumulation for the first time. Although the majority of the species were excluders, the known hyperaccumulators Berkheya nivea N.E.Br. and B. zeyheri …

Sympatric Serpentine Endemic Monardella (Lamiaceae) Species Maintain Habitat Differences Despite Hybridization, Kathleen M. Kay, Suzie Woolhouse, Brett A. Smith, Nathaniel S. Pope, Nishanta Rajakaruna

Biological Sciences

Ecological differentiation and genetic isolation are thought to be critical in facilitating coexistence between related species, but the relative importance of these phenomena and the interactions between them are not well understood. Here, we examine divergence in abiotic habitat affinity and the extent of hybridization and introgression between two rare species of Monardella (Lamiaceae) that are both restricted to the same serpentine soil exposure in California. Although broadly sympatric, they are found in microhabitats that differ consistently in soil chemistry, slope, rockiness and vegetation. We identify one active hybrid zone at a site with intermediate soil and above-ground characteristics, and …

A Global Forum On Ultramafic Ecosystems: From Ultramafic Ecology To Rehabilitation Of Degraded Environments, Guillaume Echevarria, Alan J. M. Baker, Robert S. Boyd, Antony Van Der Ent, Takafumi Mizuno, Nishanta Rajakaruna, Shota Sakaguchi, Aida Bani

Biological Sciences

The 9th International Conference on Serpentine Ecology (ICSE) was held in Tirana and Pogradec (Albania) from June 5 to 9, 2017. More than 100 delegates from 29 countries around the world gathered to present their research on recent advances in: (i) ultramafic soils, (ii) biogeochemistry, (iii) diversity of ultramafic flora, microflora and fauna, (iv) ecophysiology of ultramafic-adapted organisms, (v) interactions between ultramafic organisms and their ecology, (vi) nature rehabilitation of degraded ultramafic environments (resulting from mining activities), and (vii) the production of bio-based metals through agromining technology. Additionally, the ICSE featured the first symposium on ultramafic aquatic ecology and ecotoxicology. …

Ultramafic Vegetation And Soils In The Circumboreal Region Of The Northern Hemisphere, Anzhelika Teptina

Biological Sciences

The paper summarizes literature on climate, soil chemistry, vegetation and metal accumulation by plants found on ultramafic substrata in the circumboreal zone (sensu Takhtajan, Floristic regions of the world, 1986) of the Northern Hemisphere. We present a list of 50 endemic species and 18 ecotypes obligate to ultramafic soils from the circumboreal region of Holarctic, as well as 30 and 2 species of Ni and Zn hyperaccumulators, respectively. The number of both endemics and hyperaccumulators are markedly lower compared to that of the Mediterranean and tropical regions. The diversity of plant communities on ultramafics soils of the circumboral region is …

Diversity And Functional Traits Of Lichens In Ultramafic Areas: A Literature Based Worldwide Analysis Integrated By Field Data At The Regional Scale, Sergio E. Favero-Longo, Enrica Matteucci, Paolo Giordani, Alexander G. Paukov, Nishanta Rajakaruna

Biological Sciences

While higher plant communities found on ultramafics are known to display peculiar characteristics, the distinguishability of any peculiarity in lichen communities is still a matter of contention. Other biotic or abiotic factors, rather than substrate chemistry, may contribute to differences in species composition reported for lichens on adjacent ultramafic and non-ultramafic areas. This work examines the lichen biota of ultramafics, at global and regional scales, with reference to species-specific functional traits. An updated world list of lichens on ultramafic substrates was analyzed to verify potential relationships between diversity and functional traits of lichens in different Köppen–Geiger climate zones. Moreover, a …

Lessons On Evolution From The Study Of Edaphic Specialization, Nishanta Rajakaruna

Biological Sciences

Plants adapted to special soil types are ideal for investigating evolutionary processes, including maintenance of intraspecific variation, adaptation, reproductive isolation, ecotypic differentiation, and the tempo and mode of speciation. Common garden and reciprocal transplant approaches show that both local adaptation and phenotypic plasticity contribute to edaphic (soil-related) specialization. Edaphic specialists evolve rapidly and repeatedly in some lineages, offering opportunities to investigate parallel evolution, a process less commonly documented in plants than in animals. Adaptations to soil features are often under the control of major genes and they frequently have direct or indirect effects on genes that contribute to reproductive isolation. …

Effect Of The Specific Carbohydrate Diet On The Microbiome Of A Primary Sclerosing Cholangitis And Ulcerative Colitis Patient, Alanna Dubrovsky, Christopher Kitts

Biological Sciences

A 20-year-old female was diagnosed with ulcerative colitis (UC) at age 14 and primary sclerosing cholangitis (PSC) at age 16. The PSC was successfully treated with high doses of oral vancomycin; however, the UC was more difficult to manage. After many drug treatments failed to treat the UC, the patient began following the specific carbohydrate diet (SCD). This report documents fecal microbiome changes resulting from following the SCD for two weeks. The DNA extracted from fecal samples was subjected to 16S rRNA gene sequencing to quantify bacterial species abundance. Not only were substantial changes in the fecal bacterial composition detectable …

Heavy Metals In Seaweeds From A Polluted Estuary In Coastal Maine, Ian D. Medeiros, Arthur C. Mathieson, Nishanta Rajakaruna

Biological Sciences

Seaweeds (macroalgae) accumulate heavy metals from seawater and can therefore serve as biological monitors of marine pollution. In this paper, we present data on the tissue chemistry of seaweeds from the area of Callahan Mine, an intertidal copper and zinc mine in Brooksville, ME, USA, abandoned in the 1970s and now designated as a Superfund site. The mine is located on the Goose Pond estuary, which drains into the ocean via a tidal waterfall at Goose Falls. Seaweed tissue samples from this estuary had the same relative concentrations of metals as had been reported previously in water samples from this …

Floristic Response To Urbanization: Filtering Of The Bioregional Flora In Indianapolis, Indiana, Usa, Rebecca W. Dolan, Myla F.J. Aronson, Andrew L. Hipp

Biological Sciences

PREMISE OF THE STUDY: Globally, urban plant populations are becoming increasingly important, as these plants play a vital role in ameliorating effects of ecosystem disturbance and climate change. Urban environments act as filters to bioregional flora, presenting survival challenges to spontaneous plants. Yet, because of the paucity of inventory data on plants in landscapes both before and after urbanization, few studies have directly investigated this effect of urbanization.

METHODS: We used historical, contemporary, and regional plant species inventories for Indianapolis, Indiana USA to evaluate how urbanization filters the bioregional flora based on species diversity, functional traits, and phylogenetic community structure. …

Ultramafic Geoecology Of South And Southeast Asia, M.L. Galey, A. Van Der Ent, M.C.M. Iqbal, N. Rajakaruna

Biological Sciences

Globally, ultramafic outcrops are renowned for hosting foras with high levels of endemism, including plants with specialised adaptations such as nickel or manganese hyperaccumulation. Soils derived from ultramafic regoliths are generally nutrient-deficient, have major cation imbalances, and have concomitant high concentrations of potentially phytotoxic trace elements, especially nickel. The South and Southeast Asian region has the largest surface occurrences of ultramafic regoliths in the world, but the geoecology of these outcrops is still poorly studied despite severe conservation threats. Due to the paucity of systematic plant collections in many areas and the lack of georeferenced herbarium records and databased information, …

The Alpine Vascular Plants Of Baxter State Park, Maine, Usa, Abigail J. Urban, Glen H. Mittelhauser, Matthew Dickinson, N. Rajakaruna

Biological Sciences

We conducted 12 days of field surveys on five mountains over 1100 m in elevation (Katahdin, North Brother, South Brother, Mount Coe, and The Owl) in Baxter State Park (BSP), Maine during the summers of 2013–14. In addition, we examined historic manuscripts, unpublished data, and herbarium records for plant records from the five mountains. Katahdin, the largest and tallest of the five mountains, has a rich history of botanical exploration and we documented 1559 herbarium vouchers that were collected from the mountain, primarily before the mid-1900s. Combining all data sources, we documented 38 families, 87 genera, and 131 taxa of …

Role Of Woody Biochar And Fungal-Bacterial Co-Inoculation On Enzyme Activity And Metal Immobilization In Serpentine Soil, Tharanga Bandara, Indika Herath, Prasanna Kumarathilaka, Mihiri Seneviratne, Gamini Seneviratne, Nishanta Rajakaruna, Meththika Vithanage, Yong Sik Ok

Biological Sciences

Purpose

In this study, we investigated the effect of biochar (BC) and fungal bacterial co-inoculation (FB) on soil enzymatic activity and immobilization of heavy metals in serpentine soil in Sri Lanka.

Materials and methods

A pot experiment was conducted with tomatoes (Lycopersicon esculentum L.) at 1, 2.5, and 5 % (w/w) BC ratios. Polyphenol oxidase, catalase and dehydrogenase activities were determined by idometric, potassium permanganate oxidisable, and spectrophotometric methods, respectively. Heavy metal concentrations were assessed by 0.01 M CaCl₂ and sequential extraction methods.

Results and discussion

An increase in BC application reduced polyphenol oxidase, …

Drivers Of Redistribution Of Fishing And Non-Fishing Effort After The Implementation Of A Marine Protected Area Network, Reniel B. Cabral, Steven D. Gaines, Brett A. Johnson, Tom W. Bell, Crow White

Biological Sciences

Marine spatial planning (MSP) is increasingly utilized to sustainably manage ocean uses. Marine protected areas (MPAs), a form of spatial management in which parts of the ocean are regulated to fishing, are now a common tool in MSP for conserving marine biodiversity and managing fisheries. However, the use of MPAs in MSP often neglects, or simplifies, the redistribution of fishing and non-fishing activities inside and outside of MPAs following their implementation. This redistribution of effort can have important implications for effective MSP. Using long-term (14 yr) aerial surveys of boats at the California Channel Islands, we examined the spatial redistribution …

Plant Growth Promotion By Bradyrhizobium Japonicum Under Heavy Metal Stress, M. Seneviratne, S. Gunaratne, T. Bandara, L. Weerasundara, Nishanta Rajakaruna, G. Seneviratne, M. Vithanage

Biological Sciences

The increase in usage of heavy metals in different industrial activities causes their existence in effluents. Excessive concentrations of these heavy metals pollute soil and water. Heavy metals cause toxicities and other harmful effects not only in humans and animals but also in plants and soil microorganisms. Heavy metals disrupt many biochemical and physiological activities in bacteria, including growth, development, enzyme and hormone production. Indole acetic acid (IAA) is one of the most important hormones in plants, which is secreted by both bacteria and plants. The present study assessed the effects of Ni, Pb and Cu on the growth of …

Limestone Flora Of The Simonton Corner Quarry Preserve, Rockport, Maine, Usa, Margaret Stern, Ian D. Medeiros, Luka Negoita, N. Rajakaruna

Biological Sciences

Limestone is a distinctive substrate that has significant effects on soils and plants. The present study characterizes the diversity of vascular plants, bryophytes, and lichens at the Simonton Corner Quarry Preserve, an abandoned limestone quarry in Rockport, Maine, USA, which was in operation in the late 1800s. We document vascular plant diversity and associated edaphic features (i.e., soil pH and elemental chemistry) using 30 535 meter plots spread throughout the site. For vascular plants, 114 species in 96 genera and 50 families were observed; few of these species are known to prefer calcareous environments, and 38% are nonnative. Conversely, the …

A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna

Biological Sciences

Strong environmental gradients and varied land-use practices have generated a mosaic of habitats harboring distinct plant communities on islands on the coast of Maine. Botanical studies of Maine’s islands, however, are generally limited in number and scope. Baseline studies of Maine’s islands are necessary for assessing vegetation dynamics and changes in habitat conditions in relation to environmental impacts imposed by climate change, rising sea levels, invasive species, pests and pathogens, introduced herbivores, and human disturbance. We conducted a survey of the vascular plants and soils of forest, field, and ocean-side communities of Great Duck and Little Duck Islands, ME. These …

Solidago Gigantea Plants From Nonnative Ranges Compensate More In Response To Damage Than Plants From The Native Range, Huixuan Liao, Priscila Gurgel, Robert Pal, Ragan Callaway

Biological Sciences

Resistance and tolerance are two ways that plants cope with herbivory. Tolerance, the ability of a plant to regrow or reproduce after being consumed, has been studied less than resistance, but this trait varies widely among species and has considerable potential to affect the ecology of plant species. One particular aspect of tolerance, compensatory responses, can evolve rapidly in plant species; providing insight into interactions between consumers and plants. However, compensation by invasive species has rarely been explored. We compared compensatory responses to the effects of simulated herbivory expressed by plants from seven Solidago gigantea populations from the native North …

Resource Partitioning Along Multiple Niche Axes Drives Functional Diversity In Parrotfishes On Caribbean Coral Reefs, Thomas C. Adam, Megan Kelley, Benjamin I. Ruttenberg, Deron E. Burkepile

Biological Sciences

The recent loss of key consumers to exploitation and habitat degradation has significantly altered community dynamics and ecosystem function across many ecosystems worldwide. Predicting the impacts of consumer losses requires knowing the level of functional diversity that exists within a consumer assemblage. In this study, we document functional diversity among nine species of parrotfishes on Caribbean coral reefs. Parrotfishes are key herbivores that facilitate the maintenance and recovery of coral-dominated reefs by controlling algae and provisioning space for the recruitment of corals. We observed large functional differences among two genera of parrotfishes that were driven by differences in diet. Fishes …