scholarly journals External power amplification drives prey capture in a spider web

2019 ◽  
pp. 201821419 ◽  
Author(s):  
S. I. Han ◽  
H. C. Astley ◽  
D. D. Maksuta ◽  
T. A. Blackledge
Keyword(s):  
Muscle Power ◽  
Prey Capture ◽  
Muscular Contraction ◽  
Anatomical Structures ◽  
Spider Web ◽  
Physiological Limits ◽  
Power Amplification ◽  
External Power ◽  
Multiple Cycles ◽  
The Web

Power amplification allows animals to produce movements that exceed the physiological limits of muscle power and speed, such as the mantis shrimp’s ultrafast predatory strike and the flea’s jump. However, all known examples of nonhuman, muscle-driven power amplification involve anatomical structures that store energy from a single cycle of muscular contraction. Here, we describe a nonhuman example of external power amplification using a constructed device: the web of the triangle-weaver spider, Hyptiotes cavatus, which uses energy stored in the silk threads to actively tangle prey from afar. Hyptiotes stretches its web by tightening a separate anchor line over multiple cycles of limb motion, and then releases its hold on the anchor line when insects strike the web. Both spider and web spring forward 2 to 3 cm with a peak acceleration of up to 772.85 m/s2 so that up to four additional adhesive capture threads contact the prey while jerking caused by the spider’s sudden stop subsequently wraps silk around the prey from all directions. Using webs as external “tools” to store energy offers substantial mechanical advantages over internal tissue-based power amplification due to the ability of Hyptiotes to load the web over multiple cycles of muscular contraction and thus release more stored energy during prey capture than would be possible with muscle-driven anatomical elastic-energy systems. Elastic power amplification is an underappreciated component of silk’s function in webs and shows remarkable convergence to the fundamental mechanical advantages that led humans to engineer power-amplifying devices such as catapults and ballistae.

scholarly journals Snap-jaw morphology is specialized for high-speed power amplification in the Dracula ant, Mystrium camillae

2018 ◽  
Vol 5 (12) ◽  
pp. 181447 ◽  
Author(s):  
Fredrick J. Larabee ◽  
Adrian A. Smith ◽  
Andrew V. Suarez
Keyword(s):  
High Speed ◽  
Muscle Power ◽  
Element Analysis ◽  
Predator Prey ◽  
Mantis Shrimp ◽  
Power Amplification ◽  
Form Function ◽  
Function Relationship ◽  
Relationship Of ◽  
Insight Into

What is the limit of animal speed and what mechanisms produce the fastest movements? More than natural history trivia, the answer provides key insight into the form–function relationship of musculoskeletal movement and can determine the outcome of predator–prey interactions. The fastest known animal movements belong to arthropods, including trap-jaw ants, mantis shrimp and froghoppers, that have incorporated latches and springs into their appendage systems to overcome the limits of muscle power. In contrast to these examples of power amplification, where separate structures act as latch and spring to accelerate an appendage, some animals use a ‘snap-jaw’ mechanism that incorporates the latch and spring on the accelerating appendage itself. We examined the kinematics and functional morphology of the Dracula ant, Mystrium camillae , who use a snap-jaw mechanism to quickly slide their mandibles across each other similar to a finger snap. Kinematic analysis of high-speed video revealed that snap-jaw ant mandibles complete their strike in as little as 23 µsec and reach peak velocities of 90 m s −1 , making them the fastest known animal appendage. Finite-element analysis demonstrated that snap-jaw mandibles were less stiff than biting non-power-amplified mandibles, consistent with their use as a flexible spring. These results extend our understanding of animal speed and demonstrate how small changes in morphology can result in dramatic differences in performance.

scholarly journals In situ three-dimensional spider web construction and mechanics

2021 ◽  
Vol 118 (33) ◽  
pp. e2101296118
Author(s):  
Isabelle Su ◽  
Neosha Narayanan ◽  
Marcos A. Logrono ◽  
Kai Guo ◽  
Ally Bisshop ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Hierarchical Structures ◽  
Spider Webs ◽  
Spider Web ◽  
Web Geometry ◽  
Under Construction ◽  
The Web

Spiders are nature’s engineers that build lightweight and high-performance web architectures often several times their size and with very few supports; however, little is known about web mechanics and geometries throughout construction, especially for three-dimensional (3D) spider webs. In this work, we investigate the structure and mechanics for a Tidarren sisyphoides spider web at varying stages of construction. This is accomplished by imaging, modeling, and simulations throughout the web-building process to capture changes in the natural web geometry and the mechanical properties. We show that the foundation of the web geometry, strength, and functionality is created during the first 2 d of construction, after which the spider reinforces the existing network with limited expansion of the structure within the frame. A better understanding of the biological and mechanical performance of the 3D spider web under construction could inspire sustainable robust and resilient fiber networks, complex materials, structures, scaffolding, and self-assembly strategies for hierarchical structures and inspire additive manufacturing methods such as 3D printing as well as inspire artistic and architectural and engineering applications.

scholarly journals Effects of Habitat Change on the Web Characteristics and Fitness of the Giant Wood Spider (Nephila pilipes) in Sri Lanka

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Tharaka Wijerathna ◽  
Dilini Tharanga ◽  
Inoka C. Perera ◽  
Mayuri R. Wijesinghe
Keyword(s):  
Sri Lanka ◽  
Adult Female ◽  
Prey Capture ◽  
Home Gardens ◽  
Capture Efficiency ◽  
Population Declines ◽  
Silk Thread ◽  
Close Proximity ◽  
Female Abdomen ◽  
The Web

We compare web properties and fitness of the Giant wood spider Nephila pilpes within and outside its natural rainforest habitat in Sri Lanka. The nonforest habitats comprised rural home gardens and plantations. We hypothesize that marked differences would be evident between the two habitats in (i) web properties and (ii) fitness of the female spiders. Web architectural and silk thread properties were measured in 25 webs of adult female spiders in each of the two habitats, while female abdomen size was used as the proxy for fitness. Findings support both hypotheses. The nonforest webs were more closely knit (smaller mesh spaces) and the hub was placed at higher position on the web than that in the forest webs both altering prey capture efficiency. Also, females in nonforest habitats were significantly smaller than those in the forest, indicating lowered fitness. The disparities in web characteristics and fitness are impressive given that the forest and nonforest habitats are located in close proximity, suggesting that rainforest orbweaver spiders such as Nephila pilpes may suffer population declines if the extents of natural forest continue to shrink.

Foraging behaviour in orb-web spiders (Araneidae): do web decorations increase prey capture success in Argiope keyserlingi Karsch, 1878?

2000 ◽  
Vol 48 (2) ◽  
pp. 217 ◽  
Author(s):  
M. E. Herberstein
Keyword(s):  
Foraging Behaviour ◽  
Prey Capture ◽  
Paired Comparison ◽  
Mortality Rates ◽  
Argiope Keyserlingi ◽  
Orb Web ◽  
Orb Web Spiders ◽  
The Web ◽  
Web Size ◽  
Prey Attraction

Orb web spiders in the genus Argiope attach highly visible silk bands called decorations or stabilimenta to their webs. Two different hypotheses regarding the function of these structures were investigated in the field using Argiope keyserlingi: prey attraction and anti-predatory device. The first hypothesis suggests that web decorations attract prey to the web, and webs carrying decorations will capture more prey than those without. A field census of prey capture showed that webs adorned with more decorative bands indeed captured more but similarly sized prey per hour compared with webs carrying fewer decorations. Web height or web size, however, were not related to the rate of prey capture. This pattern was confirmed by a paired comparison of prey-capture rates within individuals that increased or decreased the number of decorative bands on consecutive days. Individuals that used more decorations also captured more prey compared with days when they spun fewer decorations. The second hypothesis suggests that these structures function as anti-predatory devices and, consequently, spiders on decorated webs benefit from a lower rate of mortality than spiders on undecorated webs. A census of the mortality rates of spiders over 19 days revealed that spiders did not disappear from undecorated webs more frequently than from decorated webs. Consequently, the idea that web decorations act as anti-predatory devices in A. keyserlingi was not supported.

scholarly journals Small behavioral adaptations enable more effective prey capture by producing 3D-structured spider threads

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Caroline C. F. Grannemann ◽  
Marco Meyer ◽  
Marian Reinhardt ◽  
Martín J. Ramírez ◽  
Marie E. Herberstein ◽  
...  
Keyword(s):  
Prey Capture ◽  
Behavioral Differences ◽  
Research Attention ◽  
Fiber Alignment ◽  
Web Performance ◽  
Behavioral Adaptations ◽  
Zigzag Pattern ◽  
Orb Web ◽  
The Impact ◽  
The Web

AbstractSpiders are known for producing specialized fibers. The radial orb-web, for example, contains tough silk used for the web frame and the capture spiral consists of elastic silk, able to stretch when prey impacts the web. In concert, silk proteins and web geometry affects the spider’s ability to capture prey. Both factors have received considerable research attention, but next to no attention has been paid to the influence of fiber processing on web performance. Cribellate spiders produce a complex fiber alignment as their capture threads. With a temporally controlled spinneret movement, they connect different fibers at specific points to each other. One of the most complex capture threads is produced by the southern house spider, Kukulcania hibernalis (Filistatidae). In contrast to the so far characterized linear threads of other cribellate spiders, K. hibernalis spins capture threads in a zigzag pattern due to a slightly altered spinneret movement. The resulting more complex fiber alignment increased the thread’s overall ability to restrain prey, probably by increasing the adhesion area as well as its extensibility. Kukulcania hibernalis' cribellate silk perfectly illustrates the impact of small behavioral differences on the thread assembly and, thus, of silk functionality.

scholarly journals No edge effect on quantity of prey captured in the forest-dwelling tetragnathid orb spider Metellina mengei

2020 ◽  
pp. 1-13
Author(s):  
Madeline A. Richards ◽  
Thomas Hesselberg
Keyword(s):  
Habitat Fragmentation ◽  
Edge Effect ◽  
Edge Effects ◽  
Prey Capture ◽  
Anthropogenic Effects ◽  
Behavioural Effects ◽  
Invertebrate Predators ◽  
The Creation ◽  
Prey Length ◽  
The Web

Abstract Among the most damaging anthropogenic effects for ecosystems is habitat fragmentation. One of its consequences is the creation of edges, which results in more exposed habitats that have different ecological and behavioural effects on the different species that live there. However, the nature and magnitude of these effects remain unknown for most of the animals and plants inhabiting these edge habitats. This study intends to determine if quantity of prey capture by a woodland population of the orb spider Metellina mengei is subjected to edge effects. By observing the prey capture of this species at edge and interior locations of a woodland, we found no significant effects of edge on the number of prey captured or the average prey length. Instead, we found that inclination of the web, but not web area or other measured web parameters, had a significant effect on prey capture. Therefore, this species of spider may be minimally affected by its location within the woodland and more affected by its surrounding microhabitat, which raises the possibility that non-specialised invertebrate predators could be less impacted by fragmentation than generally recognised.

scholarly journals Caught in the web: Spider web architecture affects prey specialization and spider-prey stoichiometric relationships

2018 ◽  
Vol 8 (13) ◽  
pp. 6449-6462 ◽  
Author(s):  
Lorraine Ludwig ◽  
Matthew A. Barbour ◽  
Jennifer Guevara ◽  
Leticia Avilés ◽  
Angélica L. González
Keyword(s):  
Spider Web ◽  
Web Spider ◽  
Web Architecture ◽  
Prey Specialization ◽  
The Web

scholarly journals Unique behavioural modifications in the web structure of the cave orb spider Meta menardi (Araneae, Tetragnathidae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Simonsen ◽  
Thomas Hesselberg
Keyword(s):  
Foraging Behaviour ◽  
Model Organism ◽  
Spider Web ◽  
Web Structure ◽  
Morphological Adaptations ◽  
Ecological Complexity ◽  
Surface Dwelling ◽  
Web Asymmetry ◽  
The Web ◽  
Behavioural Adaptations

AbstractIn the last decade there has been a renewed interest in the study of behavioural adaptations to environmental constraints with a focus on adaptations to challenging habitats due to their reduced ecological complexity. However, behavioural studies on organisms adapted to nutrient poor subterranean habitats are few and far between. Here, we compared both morphological traits, in terms of relative leg lengths, and behavioural traits, captured in the geometry of the spider web, between the cave-dwelling spider, Meta menardi, and two aboveground species from the same family (Tetragnathidae); Metellina mengei and Tetragnatha montana. We found that the webs of the cave spider differed significantly from the two surface-dwelling species. The most dramatic difference was the lack of frame threads with the radii in the webs instead attaching directly to the surrounding rock, but other differences in relative web size, web asymmetry and number of capture spiral threads were also found. We argue that these modifications are likely to be adaptations to allow for a novel foraging behaviour to additionally capture walking prey within the vicinity of the web. We found only limited evidence for morphological adaptations and suggest that the cave orb spider could act as a model organism for studies of behaviour in energy-poor environments.

scholarly journals The role of capture spiral silk properties in the diversification of orb webs

2012 ◽  
Vol 9 (77) ◽  
pp. 3240-3248 ◽  
Author(s):  
Anna Tarakanova ◽  
Markus J. Buehler
Keyword(s):  
Mechanical Properties ◽  
Prey Capture ◽  
Coarse Grained ◽  
Driving Factor ◽  
Web Performance ◽  
Spider Web ◽  
Orb Web ◽  
System Energy ◽  
Thread Strength

Among a myriad of spider web geometries, the orb web presents a fascinating, exquisite example in architecture and evolution. Orb webs can be divided into two categories according to the capture silk used in construction: cribellate orb webs (composed of pseudoflagelliform silk) coated with dry cribellate threads and ecribellate orb webs (composed of flagelliform silk fibres) coated by adhesive glue droplets. Cribellate capture silk is generally stronger but less-extensible than viscid capture silk, and a body of phylogenic evidence suggests that cribellate capture silk is more closely related to the ancestral form of capture spiral silk. Here, we use a coarse-grained web model to investigate how the mechanical properties of spiral capture silk affect the behaviour of the whole web, illustrating that more elastic capture spiral silk yields a decrease in web system energy absorption, suggesting that the function of the capture spiral shifted from prey capture to other structural roles. Additionally, we observe that in webs with more extensible capture silk, the effect of thread strength on web performance is reduced, indicating that thread elasticity is a dominant driving factor in web diversification.

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