In an underground cave of southern China, an eyeless river creature with an externally “visible” skull moved through the dark ...

Scientist Paul Helfrich has studied the T. bryo fish parasite for years and remains fascinated by its life cycle and potential lethality for trout and mountain whitefish.

Today, the Turtle Bay Exploration Park in Redding will release a group of young Chinook salmon into the Sacramento River, marking an important moment in their journey toward the wild.

During guided outings in a small motorboat along a Malaysian river, we would also see purple herons, endangered storks, and — a highlight of the trip — an orangutan.

Seen up close, each polyp has a tube-like body and an opening ringed with dozens of “transparent” tentacles. These ...