Nephila Pilipes Research Articles

Nephila spider male aggregation: preference for optimal female size and web clustering.

Sexual size dimorphism theory predicts biased operational sex ratios (OSRs) and an uneven distribution of males among certain females. We studied this phenomenon through a field census of the giant wood spider Nephila pilipes (family Nephilidae) in Singapore, a species where females are, on average, 6.9 times larger than males. Specifically, we tested two hypotheses concerning male distribution, given their tendency to aggregate in certain female webs. The optimal female size hypothesis predicts that males would predominantly occupy webs of intermediate-sized females. The web clustering hypothesis posits that more males would be found in webs closer together compared to those farther apart. Our snapshot census revealed a female-biased OSR (females: males = 1.85) with an uneven distribution of males in female webs. Most males were found in webs of intermediate-sized females aligning with the optimal female size hypothesis. Proximity among female webs was indicative of male presence, lending support to the web clustering hypothesis. While our study's limited sample size warrants caution, we conclude that in N. pilipes, male occupation of female webs is facilitated by the clustering of webs, and males prefer to cohabit with optimally sized, receptive females.

Insights into the Evolutionary Dynamics: Characterization of Disintegrin and Metalloproteinase Proteins in the Venom Gland Transcriptome of the Hemiscorpius lepturus Scorpion.

The Disintegrin and Metalloproteinase (ADAM) family, also known as the metalloproteinase/disintegrin/cysteine-rich (MDC) proteins, includes both secreted and transmembrane molecules involved in critical biological processes, such as cell migration, adhesion, and signaling. This study aimed to investigate the evolutionary relationships and structural characteristics of disintegrin and metalloproteinase proteins identified in the venom gland transcriptome of the scorpion Hemiscorpius lepturus. Using bioinformatics tools, we analyzed the open reading frame, conserved motifs, and primary, secondary, and tertiary structures of these proteins. Five proteins, named HLDis- Met1, HLDisMet2, HLDisMet3, HLDisMet4, and HLDisMet5, were identified. Their predicted 3- D structures were within normal ranges (Z-score between -4 to -9). Phylogenetic analysis revealed that HLDisMet1 shares similarities with proteins from various spider species (Nephila pilipes, Argiope bruennichi, Araneus ventricosus, and Trichonephila inaurata madagascariensis), HLDisMet2 with the scorpion Centruroides sculpturatus, HLDis- Met4 with the scorpion Tityus serrulatus, and HLDisMet5 with several snake species (Python bivittatus, Vipera anatolica senliki, Protobothrops mucrosquamatus, and Naja naja). These findings highlight the significant similarities between HLDisMet proteins and those found in other venomous species, suggesting a complex and diverse evolutionary pathway for venom components. The cross-species conservation observed may indicate a convergent evolutionary strategy, where different species independently develop similar venom components to adapt to similar ecological niches or prey types. This study highlights the evolutionary significance of venom diversification and its potential applications in understanding venom biology across different species.

Study on Diversity of Fungus Associated with Nephila pilipes

The fungus has various type of association with spider. They can be pathogenic or symbiotic or commensal in relationship to spiders they live on. In the current study the diversity of fungi in association with Nephila pilipes spider were recorded. The fungi were isolated from its legs and saliva. The microscopic and macroscopic characters were obtained. The measurements of hyphae, conidia and conidiophore were recorded. The fungal growth was more on legs compared to saliva. The legs of the adult spider carried more fungi than saliva as they are associated with soil, carrying microflora on their legs. Further the four different fungus isolated as aspergillus, penicillium, Trichoderma and Cladosporium. The penicillium colony had abundant growth, aspergillus had moderate growth and Cladosporium had less growth compared to Trichoderma.

Jumping spider invades an orb web to prey on a resident male

AbstractWhile surveying operational sex ratios of the giant golden orb weaverNephila pilipes(Fabricius, 1793) in Singapore, we documented a stunning case of predatory behavior of a jumping spiderViciria pavesiiThorell, 1877. A femaleV. pavesiiinvaded aN. pilipesorb web that was occupied by the resident female and four males, and successfully captured, killed, and removed one of theNephilamales. Whether araneophagy inV. pavesiiis opportunistic or a predatory ritual remains to be tested more precisely, but because the observed predatory event triggered an aggressive response by theN. pilipesalpha male, it is plausible thatV. pavesiimay engage in aggressive mimicry. We place our observation into the context of jumping spider cognition and behavioral tactics that are so far well understood only in a few spartaeine genera, notablyPortiaKarsch, 1878.ViciriaThorell, 1877, we argue, is another such jumping spider taxon worthy of behavioral scrutiny.

Self‐Healable Spider Dragline Silk Materials

AbstractDeveloping materials with structural flexibility that permits self‐repair in response to external disturbances remains challenging. Spider silk, which combines an exceptional blend of strength and pliability in nature, serves as an ideal dynamic model for adaptive performance design. In this work, a novel self‐healing material is generated using spider silk. Dragline silk from spider Nephila pilipes is demonstrated with extraordinary in situ self‐repair property through a constructed thin film format, surpassing that of two other silks from spider Cyrtophora moluccensis and silkworm Bombyx mori. Subsequently, R2, a key spidroin associated with self‐healing, is biosynthesized, with validated cohesiveness. R2 is further programmed with tunable healability (permanent and reversible) and conductivity (graphene doping; R2G) for electronics applications. In the first demonstration, film strips from R2 and R2G are woven manually into multidimensional (1D‐3D) conductive fabrics for creating repairable logic gate circuits. In the second example, a reversibly‐healable R2/R2G strip is fabricated as a re‐configurable wearable ring probe to fit fingertips of varying widths while retaining its detecting capabilities. Such a prototype displays a unique conformable wearable technology. Last, the remarkable finding of self‐healing in spider silk can offer a new material paradigm for developing future adaptive biomaterials with tailored performance and environmental sustainability.

Structural Elucidation of the Masp1 and Masp2 Protein from Nephila Pilipes Web Via Bioinformatics Approaches

Major ampullate spidroin (MaSps) from orb-weaver spp spider has recently gained interest due to its exceptional characteristics. The biomechanical and biochemical properties from MaSps offer potential in harvesting and exploiting MaSps as a promising bio-based product. However, the current research on the structural elucidation focused more onto the Nephila clavipes spider web rather than the Nephila pilipes which are more common in this region. Herein, this study integrates the used of computational power and algorithm to elucidate the 3D protein morphology of MaSp1 and MaSp2 of Nephila pilipes dragline silk protein using nearly complete amino acid sequences obtained from the protein database. In silico homology modelling via Phyre2, SWISS-MODEL and RaptorX was adopted to predict the protein structure of MaSP-1 and 2 using proteins threading, automated comparative modelling of three-dimensional (3D) protein structures and deep learning approaches. Consequently, we described a thorough 3D protein models of MaSp1 and MaSp2 with a higher percentage of coils, α-helix and a low percentage of β-sheet on repetitive regions of MaSp1 and MaSp2. The results of this current work provide insights into Bioinformatics potentials in engineering spider silk-based biomaterial and bridging the most apparent gaps in the knowledge of MaSp1 and MaSp2.

Structural and Mechanical Variations of Major Ampullate Silk Spun by Malaysian Nephila pilipes Spider

Structural and Mechanical Variations of Major Ampullate Silk Spun by Malaysian Nephila pilipes Spider

Antimicrobial potential of Indian cooperative spider, Stegodyphus sarasinorum, and Golden orb spider, Nephila pilipes hemolymph against pathogenic bacteria

Probiotic potential of thermotolerant lactic acid bacteria isolated from “Gari “a cassava-based African fermented foodBertrand Tatsinkou Fossi, Robert Ndjouenkeu

Araneid spiders of Shendurney wildlife sanctuary in southern Western Ghats, India

A survey of spiders conducted for a period of two seasons in Shendurney wildlife sanctuary revealed a total of 38 species. Nephila pilipes, Cyclosa hexatuberculata and Cyclosa bifida were the common species. Checklist of Araneid spiders is prepared.

Biocompatible spider silk-based metal-dielectric fiber optic sugar sensor.

Various optical components employed in biomedical applications have been fabricated using spider silk because of its superior properties, such as elasticity, tensile strength, biodegradability, and biocompatibility. In this study, a highly sensitive fiber optic sugar sensor is fabricated using metal-nanolayer-coated spider silk. The spider silk, which is directly collected from Nephila pilipes, a giant wood spider, is naturally a protein-based biopolymer with great flexibility, low attenuation, and easy functionalization. The surface of the spider silk-based fiber is coated with a metal nano-layer by using the glancing angle deposition technique. This fiber optic sugar sensor is based on the principle of the change in the refractive indices of sugar solutions. The attained experimental results show that the proposed sugar sensor is highly sensitive in the detection of fructose, sucrose, and glucose concentrations. This work may provide a new way to realize precise and sensitive online sugar measurements for point-of-care diagnostics.

Cylindrical Glands and Egg Sac Silk of Giant Wood Spider, Nephila pilipes

Different types of silk glands are located inside the abdomen of spider. Three pairs of cylindrical glands are developed in female giant wood spider, Nephila pilipes. In the present study, attempt have been made to explain the anatomy and histology of cylindrical glands and details of its spinning field with the help of scanning electron micrograph (SEM). The microscale topology and surface nanostructure of egg sac silk threads was studied with advance techniques of atomic force microscopy (AFM).It is concluded that, in female spider, cylindrical glands and egg sac silk produced by them plays a very important role in successful perpetuation of species. Roughness analysis of egg sac silk suggested that this biomaterial has high toughness that may be suitable for dissipating high amounts of mechanical energy. This silk is having high and stable mechanical performance. Hence, successful large scale production of this beautiful and strong, naturally pink colored spider silk will definitely open a new gate in textile sector.

Hybrid sequencing reveals the full-length Nephila pilipes pyriform spidroin 1 (PySp1)

Araneid spider silk glands can spin seven silk types that have task-specific properties owing to the higher order structure of spider silk proteins. This gives silks superior potential as novel biomaterials. Nephila pilipes, the giant golden orb-weaver, is one of the largest spiders and spins silk with exceptional torsional deformation, toughness, and other properties to support its mass; further investigation relies on a complete amino acid sequence. However, there are no full-length N. pilipes spidroin sequences; in fact, across species, most sequences remain fragmentary because of repetitive region assembly difficulties in short-read sequencing. Here, we develop a hybrid sequencing method that utilizes short-read sequencing to identify seven spidroin terminals in N. pilipes, and long-read sequencing to confirm the full-length pyriform spidroin 1 (PySp1) gene. PySp1 is 11,181 base pairs, with a single exon encoding a 3,726 amino acid protein, the QQ(x)4Qx motif, and lower repeat homogenization, distinct characteristics of genera Nephilinae PySp1. The full-length N. pilipes PySp1 sequences sheds light on spidroin evolution and demonstrates a helpful strategy to find full-length spidroins.

Male opportunistic mating increases with intensity of female sexual cannibalism in 3 web-building spiders.

Sexual conflict is common in animals, and female sexual cannibalism represents an extreme form of sexual conflict. Males in many species have evolved a variety of strategies to circumvent or decrease the risk of female sexual cannibalism. Opportunistic mating, by which a male mates with a female when she is disturbed or when she is feeding or undertaking moulting, is one of such kinds of strategies, and widely occurs in many animals, especially in spiders. However, whether the occurrence of male opportunistic mating depends on the intensity of female sexual cannibalism remains largely unexplored. We predicted a positive correlation between them. In this study, we tested this prediction by performing a series of mating trials in the laboratory using 3 species of web-building spiders with different intensities of female sexual cannibalism: Nephila pilipes, Nephilengys malabarensis, and Parasteatoda tepidariorum. We found that the occurrence of male opportunistic mating was positively, though not statistically significantly, correlated with the intensity of female sexual cannibalism, thus supporting our hypothesis. All together, we provide evidence that male opportunistic mating may have evolved to respond to the selection pressure posed by female sexual cannibalism.

The Importance of Biosemiotics for Morphology

Morphology and its relevance for systematics is a promising field for the application of biosemiotic principles in scientific practice. Genital coupling in spiders involves very complex interactions between the male and female genital structures. As exemplified by two spider species, Nephila clavipes and Nephila pilipes ssp. fenestrata, from a biosemiotic point of view the microstructures of the male bulb’s embolus and the corresponding female epigynal and vulval parts form the morphological zone of an intraspecific communication and sign-interpreting process that is one of the prerequisites for sperm transfer. Hence these morphological elements are of high taxonomic value, as they play an essential role in mating and fertilization and consequently in establishing and preserving a reproductive community. Morphology clearly benefits from a biosemiotic approach, as biosemiotics helps to sort out species-specific morphological characters and to avoid problematic typological interpretations.

Mechanical and structural properties of major ampullate silk from spiders fed carbon nanomaterials.

The dragline silk of spiders is of particular interest to science due to its unique properties that make it an exceptional biomaterial that has both high tensile strength and elasticity. To improve these natural fibers, researchers have begun to try infusing metals and carbon nanomaterials to improve mechanical properties of spider silk. The objective of this study was to incorporate carbon nanomaterials into the silk of an orb-weaving spider, Nephila pilipes, by feeding them solutions containing graphene and carbon nanotubes. Spiders were collected from the field and in the lab were fed solutions by pipette containing either graphene sheets or nanotubes. Major ampullate silk was collected and a tensile tester was used to determine mechanical properties for pre- and post-treatment samples. Raman spectroscopy was then used to test for the presence of nanomaterials in silk samples. There was no apparent incorporation of carbon nanomaterials in the silk fibers that could be detected with Raman spectroscopy and there were no significant improvements in mechanical properties. This study represents an example for the importance of attempting to replicate previously published research. Researchers should be encouraged to continue to do these types of investigations in order to build a strong consensus and solid foundation for how to go forward with these new methods for creating novel biomaterials.

DNA BARCODING OF COMMON MALAYSIAN SPIDERS USING THE CYTOCHROME OXIDASE I (COI) GENE

For the last twenty years, many newly described spiders were collected from Malaysia and in fact, more than 11,000 species were recorded in Peninsular Malaysia as well as in Sabah and Sarawak states. Scientists have put an immense effort on untangling the spider biology from its physical structure and behavior to silks and venoms. However, working with spiders is impeded by the difficulties in species identification via solely morphological methods. Thus, DNA barcoding is an alternative technique that employs standard fragment to facilitate species identification. Isolation of genomic DNA from three Malaysian spiders were performed using NucleoSpin® DNA insect extraction kit. Amplification of reference mitochondrial cytochrome oxidase I (COI) gene employing PCR with two set of primers followed by the DNA sequencing and validation through phylogenetic analysis were carried out. The commercial extraction kit was effective for the recovery of good quality of intact genomic DNA band as indicated by the integrity analysis. Both set of primers successfully amplified 100% of the samples with approximately 600 – 700 bp of PCR products. The obtained sequences (610 bp to 692 bp) were compared with the sequences available in Gene Bank. BLAST and phylogenetic analysis revealed that the analyzed individual samples belong to Nephila pilipes, Neoscona nautica and Crossopriza lyoni, respectively. Phylogenetic analysis provided unique insight into the evolutionary relationship of each analyzed sample. This study aids in an accurate identification of the selected local spider species at molecular level using the COI gene.

On a new synonymy in the spider genus Nephila Leach, 1815 (Araneidae, Nephilinae) from India with supplementary notes on colour polymorphism in the genus.

The golden orb-weaving spider genus Nephila Leach, 1815 currently has four representatives in India: Nephila dirangensis Biswas Biswas, 2006, Nephila kuhlii (Doleschall, 1859), Nephila pilipes (Fabricius, 1793) and Nephila robusta Tikader, 1962 (World Spider Catalog 2020). While N. kuhlii has its type locality in Java (Doleschall 1859) and that of N. pilipes in Australasia (Fabricius 1781), N. dirangensis and N. robusta are both confined to India (World Spider Catalog 2020). Tikader (1962) described the species N. robusta based on a single female specimen collected in West Bengal. The original genitalic illustrations of this species, however, show close resemblance to that of N. pilipes, indicating its possible synonymy with the latter. To confirm the novelty of N. robusta, we examined its type specimen and the result is presented below. Additionally, we discuss the occurrence of colour morphs in the Indian populations of N. pilipes.

Hydrothermal Effect on Mechanical Properties of Nephila pilipes Spidroin.

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a post-treatment process to reorganize molecular structures and improve the physical strength of spider silk is reported. The major ampullate dragline silk from Nephila pilipes with a high β-sheet content and an adequate tensile strength was utilized as the study material, while that from Cyrtophora moluccensis was regarded as a reference. Our results indicated that the hydrothermal post-treatment (50–70 °C) of natural spider silk could effectively induce the alternation of secondary structures (random coil to β-sheet) and increase the overall tensile strength of the silk. Such advantageous post-treatment strategy when applied to regenerated spider silk also leads to an increment in the strength by ~2.5–3.0 folds, recapitulating ~90% of the strength of native spider silk. Overall, this study provides a facile and effective post-spinning means for enhancing the molecular structures and mechanical properties of as-spun silk threads, both natural and regenerated.

High contrast yellow mosaic patterns are prey attractants for orb‐weaving spiders

Abstract Many animals improve their foraging success by producing signals that exploit the sensory biases of potential prey, but the specific properties that make these sensory traps effective remain unclear. We combine field experiments with phylogenetic comparative analyses to investigate the visual luring properties of different signal designs in web‐building spiders. Our field experiments used cardboard spider models to examine the effects of area of colour patches, colour and pattern on the foraging success of the colourful giant wood spider, Nephila pilipes. These experiments revealed that both the colour (yellow) and pattern (yellow and black mosaic) are essential for luring prey in a high ambient light environment. We subsequently used phylogenetic comparative analyses to demonstrate an evolutionary association between prey viewing environment and spider ventral signal among 63 species of orb‐weavers from 53 genera. Combined, our data show that (a) the colour of the bright body parts of orb‐weavers is essential for both diurnal and nocturnal prey attraction, whereas the pattern and area of colour patches are important for diurnal foraging and (b) the evolution of these visual lures is associated with the viewing environment, specifically ambient light intensity. We conclude that the effectiveness of colour luring might be a major driver of the convergent evolution of yellow mosaic patterns in phylogenetically divergent orb‐weavers. Our discoveries indicate that prey colour preferences and signal efficacy play a significant role in the evolution of visually mediated prey‐luring systems. A free Plain Language Summary can be found within the Supporting Information of this article.

A Cuboid Spider Silk: Structure-Function Relationship and Polypeptide Signature.

A unique cuboid spider silk from the outer egg sac of Nephila pilipes, with an unusual square cross-section, is disclosed. The structure-function relationships within this silk are first studied through structural characterization, mechanical measurement, protein conformation, and polypeptide signature of silk proteins. This silk maintains the higher stiffness property of egg sac silks, and also shows a species difference. Environmental response of the mechanical properties within this silk are observed. Synchrotron FTIR microspectroscopy is used to monitor the silk protein conformation in a single natural silk. The β-sheet structure aligns parallel to the fiber axis with a content of 22% ± 2.6%. The de novo resulting polypeptide from the solid silk fibers are novel, and an abundant polar amino acid insertion is observed. Short polyalanine (An , n ≤ 3), alternating serine and alanine (S/A)X, and alternating glycine and alanine (G/A)X, GGX, and SSX dominates in the resulting de novo polypeptide. This accords with the composition pattern of other egg sac silk proteins, besides the rarely observed GGX. This study broadens the library of egg sac spider silks and provides a new perspective to uncover structure-function relationships in spider silk.