Knot formation reduces water exchange by adult males of the hairworm,Paragordius varius(Nematomorpha: Gordioidea)

Autor: Blake W. Nelson, Jay A. Yoder, Andrew E. Rosselot, Andrew J. Jajack
Rok vydání: 2014
Předmět:
Zdroj: Marine and Freshwater Behaviour and Physiology. 47:299-311
ISSN: 1029-0362
1023-6244
DOI: 10.1080/10236244.2014.941171
Popis: To examine how aggregation by hairworms may enhance survival in freshwater, we determined water balance characteristics of Paragordius varius in groups of different sizes. P. varius is hyperosmotic resulting in high body water content and functions down to one-half of water stores. Absence of a critical transition temperature implies a watertight, low-porosity cuticle. Aggregated worms lose water slowly, as a physiological consequence of reduced motor activity. The water balance strategy shifts from a reliance on high dehydration tolerance for isolated individuals, affording high water loss rates, to suppressed activation energy when aggregated, wherein blocking water gain is important when water loss is slower. Low water loss rate derives from stillness and aggregating that facilitate mating or anti-predator defense, rather than as a behavior to regulate water loss. Presence of hairworms in streams is an indicator of high-quality water that is necessary to maintain water balance.
Databáze: OpenAIRE
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