Initially, the worm was thought to obtain a permanent shelter from predation at a minor expense to the coral. However, experimental work has shown that the cost to the coral is minimal and that the worms can provide two quite significant benefits to the coral: First, the top of the calcareous operculum is secreted in the form of multiple sharp rays.
“Olde mossie-backed divers” such as myself, were usually told the urine tale in our scuba classes in the late 1960s or early 1970s; but once we started to think about it, particularly as scientists (junior grade), it made no sense, whatsoever.
The moral is…never underestimate the power of nematocysts.
A large and intense Arctic temperature swing—more than 40 degrees above normal—has caught the attention of scientists.
Macrophotography Shows Phytoplankton Abundance Is Very High In Cool, Clear (?) Water; Is It The Same Over Coral Reefs?