TY - JOUR
T1 - Energy balance and metabolic changes in an overwintering wolf spider, Schizocosa stridulans
AU - Potts, Leslie J.
AU - Koštál, Vladimir
AU - Simek, Petr
AU - Teets, Nicholas M.
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/10
Y1 - 2020/10
N2 - Winter provides many challenges for terrestrial arthropods, including low temperatures and decreased food availability. Most arthropods are dormant in the winter and resume activity when conditions are favorable, but a select few species remain active during winter. Winter activity is thought to provide a head start on spring growth and reproduction, but few studies have explicitly tested this idea or investigated tradeoffs associated with winter activity. Here, we detail biochemical changes in overwintering winter-active wolf spiders, Schizocosa stridulans, to test the hypothesis that winter activity promotes growth and energy balance. We also quantified levels of putative cryoprotectants throughout winter to test the prediction that winter activity is incompatible with biochemical adaptations for coping with extreme cold. Body mass of juveniles increased 3.5-fold across winter, providing empirical evidence that winter activity promotes growth and therefore advancement of spring reproduction. While spiders maintained protein content throughout most of the winter, lipid content decreased steadily, suggesting either a lack of available prey to maintain lipids, or more likely, an allometric shift in body composition as spiders grew larger. Carbohydrate content showed no clear seasonal trend but also tended to be higher at the beginning of the winter. Finally, we tested the hypothesis that winter activity is incompatible with cryoprotectant accumulation. However, we observed accumulation of glycerol, myo-inositol, and several other cryoprotectants, although levels were lower than those typically observed in overwintering arthropods. Together, our results indicate that winter-active wolf spiders grow during the winter, and while cryoprotectant accumulation was observed in the winter, the modest levels relative to other species could make them susceptible to extreme winter events.
AB - Winter provides many challenges for terrestrial arthropods, including low temperatures and decreased food availability. Most arthropods are dormant in the winter and resume activity when conditions are favorable, but a select few species remain active during winter. Winter activity is thought to provide a head start on spring growth and reproduction, but few studies have explicitly tested this idea or investigated tradeoffs associated with winter activity. Here, we detail biochemical changes in overwintering winter-active wolf spiders, Schizocosa stridulans, to test the hypothesis that winter activity promotes growth and energy balance. We also quantified levels of putative cryoprotectants throughout winter to test the prediction that winter activity is incompatible with biochemical adaptations for coping with extreme cold. Body mass of juveniles increased 3.5-fold across winter, providing empirical evidence that winter activity promotes growth and therefore advancement of spring reproduction. While spiders maintained protein content throughout most of the winter, lipid content decreased steadily, suggesting either a lack of available prey to maintain lipids, or more likely, an allometric shift in body composition as spiders grew larger. Carbohydrate content showed no clear seasonal trend but also tended to be higher at the beginning of the winter. Finally, we tested the hypothesis that winter activity is incompatible with cryoprotectant accumulation. However, we observed accumulation of glycerol, myo-inositol, and several other cryoprotectants, although levels were lower than those typically observed in overwintering arthropods. Together, our results indicate that winter-active wolf spiders grow during the winter, and while cryoprotectant accumulation was observed in the winter, the modest levels relative to other species could make them susceptible to extreme winter events.
KW - Cryoprotectants
KW - Energy stores
KW - Winter activity
KW - Wolf spiders
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U2 - 10.1016/j.jinsphys.2020.104112
DO - 10.1016/j.jinsphys.2020.104112
M3 - Article
C2 - 32891618
AN - SCOPUS:85090546732
SN - 0022-1910
VL - 126
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
M1 - 104112
ER -