We examined the defaecation behaviour of Argiope aurantia both in natural situations and in a greenhouse. The spiders defaecated more frequently at night than during the day. The nightly pattern of defaecation was not related to time of feeding. A. aurantia displayed at least two distinct behaviours related to defaecation, one of which involved leaving the web. These results are discussed in re...

Introduction: Biosorption of heavy metals can be an effective process for the removal of heavy metal ions from aqueous solutions. Also, living lichens are known to accumulate metals across their surface. Materials and methods: In this study, the biosorption of cadmium ions Cd (II) by the lichens Acarospora strigata, Lecanora muralis and Caloplaca aurantia was investigated in aqueous solution i...

The effects of various metabolic inhibitors on the motility of Spirochaeta aurantia were investigated. After 15 min in sodium arsenate buffer, 90% of cells remained motile even though adenosine triphosphate levels dropped from 5.6 to 0.1 nmol/mg (dry weight) of cells. After 70 min in sodium arsenate, 5% of cells were motile. Addition of phenazine methosulfate plus ascorbate at this time resulte...

Background: To curtail competition with their own sperm, males of several spider and insect species mutilate their genitals or sacrifice themselves entirely using their genital parts or their whole dead bodies as mating plugs. The orb-web spider, Argiope aurantia, is a species characterized by both male self-sacrifice and extreme female-biased sexual size dimorphism. Plugs may reduce female mat...

The carbohydrate-binding specificity of Aleuria aurantia lectin was investigated by analyzing the behavior of a variety of fucose-containing oligosaccharides on an A. aurantia lectin-Sepharose column. Studies with complex-type oligosaccharides obtained from various glycoproteins by hydrazinolysis and their partial degradation fragments indicated that the presence of the alpha-fucosyl residue li...

Hypotheses for the adaptive significance of extreme female-biased sexual size dimorphism (SSD) generally assume that in dimorphic species males rarely interfere with each other. Here we provide the first multivariate examination of sexual selection because of male-male competition over access to females in a species with 'dwarf' males, the orb-weaving spider Argiope aurantia. Male A. aurantia t...