20th International Congress of Arachnology

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of Florida, USA; 2Department of Biological Sciences,
University of Pittsburgh, USA
Understanding the design of prey defenses, such as
aposematic colors, involves understanding the per-
ceptual and cognitive abilities of predators that drive
their evolution. Research in this area has focused on
‘key’ predators (e.g., birds), with less attention paid to
invertebrate predators. To understand selection pres-
sures that jumping spiders exert on prey color patterns,
we first examined natural color biases in several species
of both generalist and specialist predators across five
jumping spider genera. Experiments using artificially-
colored prey have revealed a few common themes. First,
generalist predators typically avoided color patterns
that are often associated with chemically-defended
prey (e.g., red, yellow, and black-and-white stripes).
Moreover, while these color biases generally appear to
have innate components, they are also quite flexible
in both the lab and field. In the lab, spiders can be
‘trained’ to develop either preferences or aversions by
exposing them to different combinations of natural-
occurring prey. In the field, we find additional evidence
that prey color biases are flexible and shaped by experi-
ence: different populations (exposed to different types
of colorful prey) exhibit different (and predictable)
prey color biases. Finally, we examine the idea that
species with the strongest aversions to aposematic color
patterns also have the highest susceptibility to prey
toxins. We discuss the implications of these findings
for the evolution of prey coloration. Moreover, many
of the colors that females avoid when foraging are the
same colors that males incorporate into their colorful
courtship displays suggesting that male color patterns
may act as sensory traps to avoid cannibalism; we will
discuss ongoing work examining potential spillover
between a female’s learned food color biases and her
responses to the same colors in male courtship, and
implications for the evolution of elaborate male color-
ation in salticids.
Keywords: Salticidae, color, foraging, mate choice,
sexual selection, prey choice
Oral presentation
Leg injuries and wound repair among
cosmetid harvestmen
Victor R. Townsend Jr., Maynard H. Schaus
Virginia Wesleyan College, 1584 Wesleyan Drive,
Norfolk, VA 23502 USA
Previous studies of leg injuries in harvestmen have
generally focused on the fitness consequences of leg loss
for individuals that use autospasy as a secondary defense.
In this study, we examined the rates of leg injuries among
three species of cosmetid harvestmen, assessed the impact
of leg damage upon locomotion in two species and inves-
tigated the process of wound healing over a 10 day period
in one species. We observed considerable interspecific
variation in leg injuries among male and female harvest-
men. We also observed interspecific differences in the rate
of damage in relation to leg position, with leg IV exhibiting
the highest rate of injury. We hypothesize that interspecific
variation in leg injuries may reflect encounters with differ-
ent types of predators associated with specific habitats. With
respect to the functional significance of leg damage, indi-
viduals with injuries (lab-induced) to leg IV (less than 48
hrs post-injury) walked at speeds significantly slower than
uninjured adults or individuals collected from the field that
had fully healed leg wounds. In the lab, we assessed wound
healing by damaging femora IV of adults with a scalpel and
observing the changes in the wounds over time. Using SEM,
we classified wounds into four distinct stages: fresh (within
0–24 hrs, hemolymph coagulum forms), recent (from
48–144 hrs, hemolymph coagulum has smooth, featureless
surface), older (at least 172 hrs post-injury, hemolymph
coagulum is scale-like with observable cell fragments and
fibers), and fully healed (scale replaced by new cuticle
growth that may include setae and 1–2 auxillary claws
on terminal stump). We also used SEM to examine leg inju-
ries of an additional 41 individuals collected from the field.
Although we did not observe any fresh wounds, we found
multiple individuals that had healing wounds (recent or
older) and several harvestmen with fully healed injuries.
Keywords: Opiliones, neotropical, natural history,
Cosmetidae, morphology, SEM
190 DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
Cushing