Today's featured article for November 26, 2024
Heptamegacanthus is a genus of acanthocephalans (thorny- or spiny-headed parasitic worms) containing a single species, Heptamegacanthus niekerki. This worm is a parasite of the endangered giant golden mole found only in isolated forests near East London and in the Transkei, both in South Africa. The worms are about 4 millimetres (0.2 in) long and 2 millimetres (0.08 in) wide with minimal sexual dimorphism. Their body consists of a short trunk and a proboscis with 40 to 45 hooks arranged in rings, which are used to pierce and hold the rectal wall of its host. The life cycle of H. niekerki remains unknown; however, like other acanthocephalans, it likely involves complex interactions with at least two hosts. Although the intermediate host for Heptamegacanthus is not definitively identified, it is presumed to be an arthropod, such as an insect, which is eaten by the giant golden mole. The worms then mature and reproduce sexually within the mole's lower gastrointestinal tract, creating eggs which are released in its feces. (Full article...)
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Picture of the day for November 26, 2024
Ice eggs

Ice eggs, also known as ice balls, are a rare phenomenon caused by a process in which small pieces of sea ice in open water are rolled over by wind and currents in freezing conditions and grow into spheroid pieces of ice. They sometimes collect into heaps of balls on beaches where they pack together in striking patterns. The gentle churn of water, blown by a suitably stiff breeze, makes concentric layers of ice form on a seed particle that then grows into the floating ball as it rolls through the freezing currents. This formation of ice eggs was photographed in 2014 on Stroomi Beach in Tallinn, Estonia. The temperature was around −20 to −15 °C (−4 to 5 °F), and the diameter of each ball around 5 to 10 centimetres (2 to 4 in).

Photograph credit: Aleksandr Abrosimov