Winter adaptations of the leaf litter and soil arthropod Collembola

OR: Are these guys living amongst us?

Jeff McClenahan

March, 2006

Winter Ecology – Spring 2006

Mountain Research Station – University of Colorado, Boulder

What are Collembola, and why the heck do we care?

Primitive, wingless, non-insect Hexapods Leaf litter decomposers Diets composed of fungi and algae*

*Verhoef et al., 1988

Components of winter ecology we have seen

Adaptations to cold Evidence of biotic soil activity Below-snow temperatures that support life The Antarctic is cold

Winter active species Ceratophsella sigillata*

Temperature dependent dormancy during summer Main growing season is winter Uses antifreeze molecules in algae: polyols

*Zettel, 2000

Glycerol production in Gomphiocephalus hodgsoni*

Produced via hydrolysis of triaclglycerols Able to enter the glycolytic pathway with help of ATP High concentration in October and lower in January

(Antarctic) Measured super cooling point (SCP) as low as -38 degrees

C

*Sinclair and Sjursen, 2001

Partial desiccation in Onychiurus articus*

Long periods of -2.5 degrees C, resulting in reduced water content

Lowered SCP from -6.1 to -15.5 degrees C Gained normal body weight within 24 hours when water

was available

*Worland, 1996

Brief look at the process of ecdysis

Unexpected role of ecdysis in Tullbergia antarctica*

Ametabolous ecdysis: sheds cuticle throughout life, even after adulthood

Sheds cuticle as a means to rid themselves of ice

*Worland, 2005

What does this all mean?

Arthropods where we don’t expect them? 9000 named species Inhabit high elevations and high latitudes Evidence suggests that these winter systems are dynamic

Alpine tundra?

Sub-alpine forests?

Cited references

Sinclair BJ and Sjursen H. 2001. Cold tolerance of the Antarctic springtail Gomphiocephalus hodgsoni. Antarctic Science 13:271-279

Worland MR. 1996. The relationship between water content and cold tolerance in the arctic collembolan Onychiurus arcticus. European Journal of Entomology 93:341-348

Worland MR. 2004. Factors that influence freezing in the sub-Antarctic springtail Tullbergia antarctica. Journal of Insect Physiology 51:881-894

Verhoef HA, Prast JE, Verweij RA. 1988. Relative importance of Fungi and Algae in the diet and nitrogen nutrition of Orchesella cincta and Tomocerus minor. Functional Ecology 2:195-201

Zettel J. 2000. Alpine Collembola-adaptations and strategies for survival in harsh conditions. Zoology-Analysis of Complex Systems 102:73-89