Upside-down jellyfish lob tiny grenades to kill prey
Mucus secreted by a group of jellies, known as upside-down jellyfish, is filled with tiny, wriggling cell masses that allow them to fire stinging substances from a distance.For years, snorkelers in mangrove forests around the Florida Keys, Caribbean, and Micronesia have reported a bizarre and unpleasant phenomenon. Despite being careful not to touch the jellyfish littering the seafloor below, swimmers sometimes feel a stinging sensation that seems to come from the water itself. After encountering stinging water while studying the jellies, scientists sought to get to the bottom of these prickling shores. To their surprise, they discovered that mucus secreted by these jellyfish is filled with tiny, wriggling cell masses that allow them to fire stinging substances from a distance. The researchers reported the newly identified structures, which they dubbed cassiosomes, on February 13 in the journal Communications Biology.“It was really one of the most shocking days in my history...