The White-tailed spider was fished out of some water and played dead whilst being photographed, before it went on its way. The first image shows a close-up of the underside of the cephalothorax with a unique pattern that appears to be due to the creeping growth of a white filament-like structure across it. The same growth isn’t obvious on the underside of the abdomen. It’s not clear from the images where this growth has come from but possibly at the connection of the cephalothorax to the abdomen. Not sure what this is but possibly a fungal infection similar to Puppeteer Fungus that affects flies. One for the spider experts.