Title
Submersion Tolerance Among Riparian and Non-Riparian Spiders
Start Date
13-11-2015 8:00 PM
End Date
13-11-2015 9:59 PM
Description
Terrestrial arthropods that inhabit dynamic boundaries between terrestrial and lotic systems are under constant risk of flooding. Many spiders may have evolved behavioral, physiological, or morphological adaptations to cope with flooding either through avoidance or submersion tolerance. Mechanisms for coping with periodic flooding have important implications for predicting species composition, recolonization, and resilience against flood-related disturbance for riparian arthropod communities. We examined submersion tolerance of spiders by taxon, size, and microhabitat. We compared web-building and cursorial, riparian and non-riparian, and ground-dwelling versus more arboreal species. We submerged individual spiders for three hours in distilled water and recorded survival, activity level immediately after removal, and activity level eight hours after removal (N = 1,113). During trials we noted spiders that were in hypoxic comas versus those that formed plastrons (breathing bubbles) during submersion. We found large differences in submergence tolerance by taxon and habitat. Web-building spiders showed poor survival post submersion, even those that live on overhanging vegetation along rivers and streams. Most wolf spiders and fishing spider species showed no negative effects of submersion and most were active the entire time of submergence. We also found significant differences in submersion tolerance between populations of the same species within the riparian zone compared to populations from other habitats, indicating population-level local adaptation to flooding for multiple species. Spiders with dense or spatulate setae (i.e. “hairy spiders”) appeared particularly well adapted to form plastrons during inundation and suggest one function for dense setae on some species. This morphological feature alone may account for the ability of lycosids and pisaurids to exploit the stochastic interface of the river and adjacent terrestrial habitats.
Type
Poster
Language
eng
Submersion Tolerance Among Riparian and Non-Riparian Spiders
Elaine Langone Center, Terrace Room
Terrestrial arthropods that inhabit dynamic boundaries between terrestrial and lotic systems are under constant risk of flooding. Many spiders may have evolved behavioral, physiological, or morphological adaptations to cope with flooding either through avoidance or submersion tolerance. Mechanisms for coping with periodic flooding have important implications for predicting species composition, recolonization, and resilience against flood-related disturbance for riparian arthropod communities. We examined submersion tolerance of spiders by taxon, size, and microhabitat. We compared web-building and cursorial, riparian and non-riparian, and ground-dwelling versus more arboreal species. We submerged individual spiders for three hours in distilled water and recorded survival, activity level immediately after removal, and activity level eight hours after removal (N = 1,113). During trials we noted spiders that were in hypoxic comas versus those that formed plastrons (breathing bubbles) during submersion. We found large differences in submergence tolerance by taxon and habitat. Web-building spiders showed poor survival post submersion, even those that live on overhanging vegetation along rivers and streams. Most wolf spiders and fishing spider species showed no negative effects of submersion and most were active the entire time of submergence. We also found significant differences in submersion tolerance between populations of the same species within the riparian zone compared to populations from other habitats, indicating population-level local adaptation to flooding for multiple species. Spiders with dense or spatulate setae (i.e. “hairy spiders”) appeared particularly well adapted to form plastrons during inundation and suggest one function for dense setae on some species. This morphological feature alone may account for the ability of lycosids and pisaurids to exploit the stochastic interface of the river and adjacent terrestrial habitats.