Plasticity in extended phenotypes: orb web architectural responses to variations in prey parameters
1School of Biological Science, University of Sydney, Sydney 2006, Australia. sblamires@thu.edu.tw
The Journal of Experimental Biology
|August 31, 2010
Summary
Spider orb web architecture is plastic, adapting to feeding frequency and prey characteristics. Web area and mesh size change, but radii number remains constant, reflecting trade-offs in silk investment.
Area of Science:
- Behavioral Ecology
- Animal Physiology
- Arachnology
Background:
- Spider orb webs are extended phenotypes, influenced by environmental factors and spider physiology.
- Orb web plasticity allows adaptation to prey variations, but nutrient effects are hard to isolate.
- Previous studies faced challenges decoupling prey nutrients from size, energy, and feeding patterns.
Purpose of the Study:
- To investigate how nutrient concentration and prey parameters influence orb web plasticity in Argiope keyserlingi.
- To control for prey protein concentration while manipulating prey size, energy density, and feeding frequency.
Main Methods:
- Analyzed nutrient concentrations of cockroaches, adult, and juvenile crickets.
- Devised experiments controlling prey protein and varying prey size, ingested mass, energy concentration, and feeding frequency.
- Observed and measured changes in orb web architecture, including decoration length, web area, mesh size, and number of radii.
Main Results:
- Argiope keyserlingi alters overall web architecture based on feeding frequency.
- Web area and mesh size were responsive to feeding frequency and prey length.
- Decoration length showed contradictory responses to prey mass/energy, suggesting confounding factors.
Conclusions:
- Orb web spiders adjust web area and mesh size based on feeding frequency and prey size, optimizing silk investment.
- The number of radii is not affected by prey parameters, indicating a fixed structural element.
- Plasticity in decoration length is complex and may involve balancing prey attraction with predator risk.
Related Concept Videos
00:58Plasticity
Plasticity is the property where an object loses its elasticity and undergoes irreversible deformation, even after the deformation forces are eliminated. If a material deforms irreversibly without increasing stress or load, then this is called ideal plasticity. For example, when a force is applied to an aluminum rod, it changes its shape, but it does not return to its original shape once the force is removed. Plastic deformation or ductility is thus a permanent deformation or change in the...
02:27Background and Environment Affect Phenotype
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
02:39Predator-Prey Interactions
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...
01:01Neuroplasticity
Neuroplasticity reflects the brain's remarkable capacity to adapt and evolve, responding dynamically to learning, experiences, or injury by reorganizing its neural circuitry. This reorganization involves creating new neural connections and refining old ones through a series of biological processes that contribute to the brain's lifelong development and adaptability.
01:21Plastic Behavior
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and reloaded.
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...