DOI: 10.5061/dryad.dz08kps7p
title: Plasticity in extend phenotype how the cobweb spider <em>Campanicola campanulata</em> altering web architecture and trade-off behavioral investments in response to prey availability variation

description: Some spiders use sand grains, soil particles, prey remains, and plant
 debris to build detritus-based, bell-shaped cobwebs. The retreat and
 gumfooted lines in cobwebs are thought to have defensive and foraging
 functions. Extended phenotypic plasticity has been proposed as a means by
 which animals alter their phenotypes in response to  changing
 conditions. Animals may display extended phenotypic plasticity as a
 consequence of environmental variation. The aim of this study was to test
 both the extended phenotypic plasticity and the trade-off hypothesis by
 looking at whether a common cobweb spider Campanicola
 campanulata alter web architecture and behavioral investments in
 response to the availability of prey. When prey availability increases,
 spiders build webs higher up, build smaller and lighter retreats, and
 cobwebs with fewer gumfooted lines and smaller capture areas. The results
 showed that spiders invested less in both foraging and defensive
 investments in the presence of a large number of ant prey. These results
 suggested that the web architecture of C. campanulata exhibits a
 high degree of plasticity in response to variations in prey availability,
 but the behavioral investments did not involve trade-offs between foraging
 and defense.
description: <strong>Study species</strong><br>
 <em>Campanicola campanulata</em> (Araneae: Theridiidae) is a
 cobweb-building spider that is widely distributed in Hubei, Zhejiang, and
 Guizhou province of China (Chen 1993). These spiders gather in cool but
 rain-proof habitats such as forests, farmlands or hillsides and mainly
 feeding on ants. We have observed that spiders often build their webs in
 places such as concave rocks, earthen walls, or under low-hanging
 branches. Each individual spider builds a complete cobweb that consists of
 anchor silks, dozens of sticky gumfooted lines, and a bell-shaped retreat
 made of silk, sand, pebbles, debris, leaves, or shells. 
 The anchor silk, composed of strands of silk, connects the
 bell-shaped retreat to stone walls, tree branch or other substrates,
 providing stability and preventing wind damage to the web. The bell-shaped
 retreat, made of silk-wrapped sand grains, soil particles, prey remains
 and plant detritus, is usually suspended and lined with silk tunnels
 (Henschel and Jocqué, 1994). This structure significantly reduces the
 spider′s vulnerability to enemies and provides a safe space for resting, ,
 mating, spawning, and caring for its young. It also offers protection
 against predators such as araneophagy spiders or birds. 
 The capture web consists of a few to several dozen radial
 gumfooted lines that extend from the edge of the bell-shaped retreat and
 are fastened to coarse sand grains or fixed substrates. These lines
 primarily function to trap preys walking underneath the web and prevent
 the invasion of enemies. Once ants are intercepted by sticky gumfooted
 lines, the vibratory signal generated by the ant's struggle will be
 transmitted to the spider in the retreat. The spider then tear the lines
 away from the substrate and pull its prey up toward the retreat, making it
 difficult for the ant to get the leverage needed for escape (Argintean et
 al. 2006).  <strong>Spider collection and
 maintenance</strong><br> From 20 to 25 March 2022, we
 collected sub-adult (i.e., 1 molt before adulthood, ~2.4 mm in body
 length) C. campanulata from Guanyin Lake Scenic Area (31º 14′ 8.66′′ N,
 114º 01′ 21.57′′ E) in Hubei Province, China, and raised them to adulthood
 in the laboratory. The spiders were maintained individually in a plastic
 box (length × width × height: 10 cm × 5 cm × 10 cm) with bamboo sticks
 attached to their inner sides to allow them to build webs. The front and
 back sides of the box were made of removable transparent Perspex glass.
 All spiders were kept in the laboratory with controlled environmental
 conditions (temperature: 25 ± 1℃; relative humidity: 80 ± 5%; photoperiod:
 14 h:10 h L : D). The bottom of the box was covered with a layer of sand
 for the spider to collect to build a retreat, and a piece of sponge with
 absorbed water was placed at the bottom of the box to provide water for
 the spider. We fed each spider with 2 ants (Monomorium sp., ~2.2 mm in
 body length) every 2 days, and the developmental status (molting) of each
 spider was checked twice daily (09:00 and 21:00).
 <strong>Experimental design and
 procedure</strong><br> We selected sixty newly matured female
 spiders (~2 days after maturity) that have been well-fed for 3 days and
 were randomly divided into 4 treatments (N = 15 in each group) with
 different number of ants : blank control (CK)—0 ants, low prey
 availability (LA)—5 ants, medium prey availability (MA)—10 ants and high
 prey availability (HA)—20 ants, respectively. All the spiders were
 transferred to a box with a layer of sand grains at the bottom, and a
 wooden stick attached to the sides and the inner wall at the top to form a
 wooden frame. Sand grains were collected in the wild habitat for spiders
 to build the retreat, while wooden frames was used as a climbing fulcrum
 for spiders to build their webs.The body size (carapace width, body
 length, and body weight) of each spider was measured before the
 experiment. We measured the body condition parameters (carapace width,
 body length, and body weight) of each spider before the experiment. All
 spiders were provided with Monomprium ants and water ad libitum two days
 before the experiment and were given 36 h to allow them to build webs,
 none were fed during the experiment. All the trails were recorded using
 video camera (HDR-CX 680; SONY). <strong>Latency
 and duration of web-building</strong><br> After being
 introduced into the experimental setup, the spider will have a period of
 exploration of the new environment, during which spiders spin silk and
 fasten it to the appropriate sand grains. Then spiders climb to the top of
 the setup via sticks on both sides and select a suitable anchor point to
 begin transporting sand grains. The period from when spiders were
 introduced into the experimental setup until they begin to transport the
 first sand grain is defined as the latency of web-building. Due to the
 energy consumption of the spider to construct the retreat and the
 gunfooted lines (Blamires et al. 2014), the spider will have several rest
 times during the web-building, but the spider will not rest for more than
 2 hours at a time (H. Zhang’s pers. obs.). Once the spider has rested for
 more than two hours, we consider the web-building process to be complete.
 The period between spiders begin to transport the first sand grain and
 when the spider finished web-building is called the duration of
 web-building. For each spider, we recorded the latency and duration of its
 web-building by analyzing the videos, because we believe that these
 parameters can more or less reflect the spider's decision on
 web-building behavior when different numbers of ants are present. Ants are
 not only dangerous prey but also potential predators for spider, and the
 roles of predator and prey may be reversed if one of them makes a mistake
 (Líznarová and Pekár, 2013; Peká rand Toft, 2015).
 <strong>Web architecture measurements and behavioral
 investments quantification</strong><br> For each web, we
 measured the parameters of web architecture including the length of anchor
 silk (ASL), the height of retreat (RH), the number of gumfooted lines
 (GLN), the height of the retreat center from the ground (CRH), the
 diameter of retreat entrance (ED), the length of each gumfooted line (GL),
 and the weight of the retreat (RW) (Figure 1D). Because the projection of
 the gumfooted lines on the ground is irregular, some gumfooted lines are
 near to the center, and the others are far away to the center, so we
 measured the length of the most inner (CRI) and the most outer (CRO)
 capture radius and use the average of the them as the average radius (CRA)
 to estimate the capture area. RW was measured after the other 8 web
 architecture parameters were measured. We cut the retreat off from the web
 and measured its weight to the nearest 0.01 mg using an electronic balance
 (FA1004N type, HANGPING).  It is well known that the
 capture area and retreat volume in the cobweb are important indicators of
 the web-building strategy and behavioral investment in capturing prey and
 avoiding predators because spiders with larger capture areas will have
 higher rates of prey encounter and foraging success (Benjamin and
 Zschokke, 2003; Blackledge and Zevenbergen, 2007; Salomon 2007;
 Zevenbergen et al. 2008; Fischer et al. 2023; Sergi et al. 2020). While
 spiders with larger retreats are less likely to be discovered by predators
 and thus face lower  predation risk (Manicom et al. 2008). We used the
 same formula in previous studies to calculate the capture area and retreat
 volume (Zhang et al., 2023a; b) and also quantify the foraging investment
 (i.e., total length of gumfooted lines, GTL) and defense investment (i.e.,
 energy consumption in building retreat, EC) during web-building (Zhang et
 al., 2023a; b).   <strong>Statistical
 analysis</strong><br> We checked the data for the normality
 and homogeneity of variance using Shapiro–Wilk and Levene tests,
 respectively. Since the data were not normally distributed, we used the
 Kruskal–Wallis test to compare the differences in web architecture and
 behavioral investments between treatments. If there was a significant
 difference in the results, Wilcoxon’s rank sum test with continuity
 correction was used to pairwise comparative the results between any 2
 treatments. We performed all statistical analyses using R 4.4.2 (R Core
 Team 2025). All tests were 2-tailed, and the P-value for significance was
 set at &lt; 0.05.
description: # Plasticity in extend phenotype how the cobweb spider *Campanicola
 campanulata* altering web architecture and trade-off behavioral
 investments in response to prey availability variation This is the dataset
 for Zhang, H.X., Zhang, H, Hu, L., Wen, L.L., & Li, C.C. 2025.
 Plasticity in extend phenotype how the cobweb spider Campanicola
 campanulata altering web architecture and trade-off behavioral investments
 in response to prey availability variation. Principle Investigator Contact
 Information: Changchun Li, Hubei Key Laboratory of Resource Utilization
 and Quality Control of Characteristic Crops, College of Life Science and
 Technology, Hubei Engineering University, Xiaogan 432000, Hubei, China;
 e-mail: [lcc386@163.com](mailto:lcc386@163.com) Date of data collection:
 March 20 to 25 2022 Location of data collection: PR China Recommended
 citation Zhang, H.X., Zhang, H, Hu, L., Wen, L.L., & Li, C.C. 2025.
 Plasticity in extend phenotype how the cobweb spider Campanicola
 campanulata altering web architecture and trade-off behavioral investments
 in response to prey availability variation ## File Information
 **DATA_Plasticity_in_extend_phenotype_how_the_cobweb_spider_Campanicola_campanulata_altering_web_architecture_and_trade_off_behavioral_investments_in_response_to_prey_availability_variation.csv** Variable List: 1. Group: Spiders in four number of ant treatments(CK, Low, Medium and High). 2. Num: number of each spider in four number of ant treatments(CK, Low, Medium and High). 3. CW(mm): carapace width of spiders in different treatments. 4. BL(mm): body lengths of spiders in different treatments. 5. BW(mg): body weight of spiders in different treatments. 6. LW(hour): latency of web-building. 7. DW(hour): duration of web-building. 8. ASL(mm): length of anchor silk. 9. RH(mm): height of retreat. 10. ED(mm): diameter of retreat entrance. 11. CRH(mm): height of retreat center from the ground. 12. CRI(mm): the length of the most inner capture radius. 13. CRO(mm): the length of the most outer capture radius. 14. GLN: number of gumfooted lines. 15. RW(mg): weight of retreat. 16. CA(cm2): capture area of the cobweb. 17. RV(mm3): volume of retreat. 18. GTL(mm): total length of gumfooted lines of the cobweb. 19. EC(10-6J): energy consumption during web-building. Data was processed/analyzed with R 4.4.2.