scholarly journals Biodiversity of orb-web spiders (family: araneidae) of buner valley, Pakistan

2022 ◽  
Vol 82 ◽  
Author(s):  
L. Luqman ◽  
K. Saeed ◽  
K. Muhammad ◽  
M. S. Ahmad ◽  
F. Akbar ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Shannon Index ◽  
Arid Area ◽  
Taxonomic Study ◽  
Simpson Index ◽  
Generic Level ◽  
Building Area ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Sweep Net

Abstract The present research was carried out to explore the spider fauna of Buner valley with taxonomic study from February 2018 to January 2019. For this purpose samples were collected, four times at each month from 4 tehsils: Daggar, Gagra, Mandan and Totalai. Two methods were used, hand picking and sweep net for collection of samples. During day and night, three habitats, arid area, agriculture land and building area were search for collection. A total of 534 samples of spider were collected from four sampling sites, in which 379 were belonging to family Araniedae. After confirmation, the identified species were belonging to 8 genera (Neoscona, Argiope, Cyclosa, Araneus, Cyrtophora, Larinia, Erivoxia and Poltys) and 19 species. 18 of them were identified to specie level while a single specie to its generic level. The genus Neoscona was the dominant genus 26.31% having 5 species while the genus Argiope 21.05% is the second dominant having 4 species followed by Cyclosa 15.78% having 3 species followed by Cyrtophora and Araneus 10.52% having two species both. The Poltys and Larinia 5.26% are the rarest genera represent single-single specie both. Statistical analysis show that specie richness (D) = 5.77, Simpson index (1-D) = 0.87, Shannon index (H) = 2.33. Diversity of spiders was evenly distributed and calculated Evenness value was H/InS = 0.5408. There is also few atypical species and Fisher alpha estimate high value (Fisher α) = 4.42. Chao-1 estimated we have reported 22 species.

Web characteristics determine niche partitioning for orb-web spiders (Araneae, Tetragnathidae) in Malaysia

2017 ◽  
Vol 51 (3) ◽  
pp. 262-275 ◽  
Author(s):  
Dzulhelmi Muhammad Nasir ◽  
Thary Gazi Goh ◽  
Asraf Bakri ◽  
Faszly Rahim ◽  
Zulqarnain Mohamed ◽  
...  
Keyword(s):  
Niche Partitioning ◽  
Orb Web ◽  
Orb Web Spiders

scholarly journals Guiding lights: Foraging responses of juvenile nocturnal orb‐web spiders to the presence of artificial light at night

Ethology ◽  
2019 ◽  
Vol 125 (5) ◽  
pp. 289-297 ◽  
Author(s):  
Nikolas J. Willmott ◽  
Jessica Henneken ◽  
Mark A. Elgar ◽  
Therésa M. Jones
Keyword(s):  
Artificial Light ◽  
Light At Night ◽  
Orb Web ◽  
Orb Web Spiders

The silk tuft web decorations of the orb-weaver Gasteracantha cancriformis : testing the prey attraction and the web advertisement hypotheses

Behaviour ◽  
2008 ◽  
Vol 145 (3) ◽  
pp. 277-295 ◽  
Author(s):  
Felipe Gawryszewski ◽  
Paulo Motta
Keyword(s):  
Drosophila Melanogaster ◽  
Foraging Success ◽  
Uv Reflectance ◽  
Web Advertisement ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Large Animals ◽  
And Control ◽  
The Web ◽  
Prey Attraction

AbstractSeveral orb-web spiders build conspicuous decorations in their webs. The prey attraction hypothesis proposes that decorations increase spider foraging success by attracting prey, and that attraction is linked to UV reflectance. Alternatively, the web advertisement hypothesis proposes that decorations are a signal that advertises the presence of the web to large animals. We tested both hypotheses for the web silk tufts of Gasteracantha cancriformis. Even though tufts are UV reflective, we did not find support for the prey attraction hypothesis. In the field, when webs with tufts painted black and control webs were compared, there were no differences in the number of prey captured, number of damaged areas in webs and type of prey captured. In the laboratory, Drosophila melanogaster did not demonstrate preference for tufted silk lines versus non-tufted silk lines. Our data also did not give support for the web advertisement hypothesis. The proportion of web destruction was similar between web with tufts painted black and control webs during four days of experimentation. Therefore, two of the most favoured hypotheses that attempt to explain decorations do not apply for web silk tufts in our study system. Instead we propose that silk tufts might be an aposematic signal.

scholarly journals PHYTOSOCIOLOGY AND STRUCTURAL CHARACTERIZATION OF WOODY REGENERATION FROM A REFORESTATION WITH NATIVE SPECIES IN SOUTHEASTERN BRAZIL

2016 ◽  
Vol 40 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Michel Anderson Almeida Colmanetti ◽  
Luiz Mauro Barbosa ◽  
Regina Tomoko Shirasuna ◽  
Hilton Thadeu Zarate do Couto
Keyword(s):  
Native Species ◽  
Sao Paulo ◽  
Shannon Index ◽  
Southeastern Brazil ◽  
São Paulo ◽  
Simpson Index ◽  
Paulo State ◽  
São Paulo State ◽  
High Diversity

ABSTRACT In Brazil, specifically in São Paulo State, there are guidelines based on the high diversity of tropical forests that instructs the restoration projects in the state (current SMA 32/2014). The main goal of this study was verify the importance and effectiveness of the high diversity of arboreal species originated from a reforestation, and its influence in a woody regenerating composition. We developed a phytosociologic study in a woody regenerating stratum of a nine year old reforestation at a Private Reserve of Natural Heritage (RPPN), in Mogi-Guaçu, São Paulo State. All specimens with height > 30 cm and Diameter at Breast Height (DBH) < 5 cm were evaluated. The woody regenerating diversity was smaller than the overstory diversity and the species composition was similar to the overstory. The Simpson index (1-D) was 0.85, Shannon index (H') was 2.46 and the Pielou index (J') was 0.60. The zoochoric dispersion syndrome was major among the species. Our results suggest that the use of high diversity of native seedlings in a reforestation leads to high diversity of species in woody regeneration stratum, after one decade of planting.

scholarly journals Gut Microbiota Play an Essential Role in the Antidiabetic Effects of Rhein

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ruifeng Wang ◽  
Pu Zang ◽  
Junxiu Chen ◽  
Fei Wu ◽  
Zhouqin Zheng ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Essential Role ◽  
Fasting Blood Glucose ◽  
Shannon Index ◽  
Simpson Index ◽  
Significant Difference ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Host Metabolism ◽  
Antidiabetic Effects

It is clear that the gut microbiota can affect host metabolism and alterations of the gut microbiota can link with metabolic disease. Rhein has been used in traditional Chinese medicine with putative antidiabetic effects. Here we show that oral administration of rhein for 6 weeks can significantly reduce fasting blood glucose (FBG) level (8.30 ± 4.52 mmol/l versus 18.89 ± 6.06 mmol/l, p < 0.01), elevate the active glucagon-like peptide 1 (GLP-1) level (22.21 ± 2.61 pmol/l verss 14.46 ± 5.22 pmol/l, p < 0.05), and increase the number of L-cells in the terminal ileum. The antidiabetic effect of rhein is abrogated in db/db mice treated with rhein in combination with broad-spectrum antibiotics. We observed that the abundance of the Bacteroidetes is increased in mice treated with rhein (0.361±0.022 versus 0.185 ± 0.055, p < 0.05,). In addition, there is no significant difference in diversity between rhein-treated groups and the controls (Shannon index: p = 0.88; Simpson index: p = 0.86). Taken together, our results indicate that modulation of the gut microbiota may play an essential role in the antidiabetic effects of rhein.

scholarly journals Correction to: Testing traditional hypotheses about prey capture efficiency in orb-web spiders

2020 ◽  
Author(s):  
Fernanda Carolina da Silva ◽  
Mateus Moleta ◽  
Camila Alves Dos Anjos ◽  
Gabriel Marra Schade ◽  
Gabriel Staichak ◽  
...  
Keyword(s):  
Prey Capture ◽  
Capture Efficiency ◽  
Orb Web ◽  
Orb Web Spiders

Memory of prey larders in golden orb-web spiders, Nephila clavipes (Araneae: Nephilidae)

Behaviour ◽  
2013 ◽  
Vol 150 (12) ◽  
pp. 1345-1356 ◽  
Author(s):  
Rafael L. Rodríguez ◽  
Robb C. Kolodziej ◽  
Gerlinde Höbel
Keyword(s):  
Field Experiment ◽  
Total Mass ◽  
Potential Effect ◽  
Continuous Variable ◽  
Adaptive Significance ◽  
Nephila Clavipes ◽  
Food Hoarding ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Prey Items

Nephila clavipes spiders accumulate prey larders on their webs. We conducted a field experiment to ask if the spiders search for larders that have been pilfered (experimentally mimicking the potential effect of kleptoparasites), and to ask if the spiders vary their search efforts according to the size of the larder. All spiders searched for larders removed from their web, and spiders that lost larger larders (i.e., consisting of more prey items) searched for longer intervals. We thus suggest that N. clavipes form memories of the size of the larders they have accumulated, and that they use those memories to regulate recovery efforts when the larders are pilfered. The content of those memories may include discrete prey counts or the accumulation of a continuous variable correlated with counts, such as the total mass of captured prey. We discuss the adaptive significance of this ability in the framework of costs related to kleptoparasites and the ecology of food hoarding.

scholarly journals Biological liquid crystal elastomers

2002 ◽  
Vol 357 (1418) ◽  
pp. 155-163 ◽  
Author(s):  
D. P. Knight ◽  
F. Vollrath
Keyword(s):  
Liquid Crystal ◽  
The Novel ◽  
Dragline Silk ◽  
New Class ◽  
Detailed Explanation ◽  
Fibrillar Collagens ◽  
Biological Liquid ◽  
Orb Web ◽  
Liquid Crystal Elastomers ◽  
Orb Web Spiders

Liquid crystal elastomers (LCEs) have recently been described as a new class of matter. Here we review the evidence for the novel conclusion that the fibrillar collagens and the dragline silks of orb web spiders belong to this remarkable class of materials. Unlike conventional rubbers, LCEs are ordered, rather than disordered, at rest. The identification of these biopolymers as LCEs may have a predictive value. It may explain how collagens and spider dragline silks are assembled. It may provide a detailed explanation for their mechanical properties, accounting for the variation between different members of the collagen family and between the draglines in different spider species. It may provide a basis for the design of biomimetic collagen and dragline silk analogues by genetic engineering, peptide- or classical polymer synthesis. Biological LCEs may exhibit a range of exotic properties already identified in other members of this remarkable class of materials. In this paper, the possibility that other transversely banded fibrillar proteins are also LCEs is discussed.

The marginal cost of structural diversity of mixed uneven-aged hard maple forests

2002 ◽  
Vol 32 (4) ◽  
pp. 616-628 ◽  
Author(s):  
Shashi Kant
Keyword(s):  
Growth Model ◽  
Acer Saccharum ◽  
Marginal Cost ◽  
Structural Diversity ◽  
Shannon Index ◽  
Forest Stand ◽  
Simpson Index ◽  
Southern Ontario ◽  
Theoretical Concepts ◽  
Size Diversity

Theoretical concepts pertaining to the marginal cost (MC) of the structural diversity of a forest stand are developed. A matrix growth model is estimated for mixed uneven-aged forest stands of hard maple (Acer saccharum Marsh.) from southern Ontario. The estimated growth model is used to derive the MC equations for the Shannon and the Simpson indices of total structural diversity (TSD), species diversity (SD), and tree-size diversity (TD). The effects of exclusion and inclusion of the opportunity cost (OC) on the MC of the TSD are compared. The contributions of SD and TD to the MC of the TSD are disaggregated. The MCs of TSD, SD, and TD for the Shannon and the Simpson indices are iso-elastic. The elasticity of the MC of the TSD for the inclusion of OC is greater than the elasticity of MC of the TSD for the exclusion of OC. The elasticities of MC of TSD, SD, and TD for the Shannon index are greater than the elasticities of MC of TSD, SD, and TD, respectively, for the Simpson index. The elasticities of MC of SD are smaller than the elasticities of MC of TD, for both indices. However, these results are specific to the hard maple forests of southern Ontario and cannot be generalized. Some general features of MC equations of structural diversity are discussed.

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