The chambered, or pearly, nautilus (Nautilus pompilius) is a charismatic cephalopod species known for its exceptional spiraling, chambered shell. It belongs to a family that has barely changed since ...

Bluefin tuna are an ocean-going fish that grow up to 10 feet long and can weigh as much as 1,200 pounds. Unlike almost all fish, bluefin tuna are warm-blooded and able to regulate their body ...

DESCRIPTION: Walruses are easily distinguished by their long, white tusks, cinnamon-brown skin, grizzled whiskers, and bodies full of blubber. Growing up to 3,750 pounds, male Pacific walruses are ...

Oases in the desert, Southwestern streams are among the most delicate ecosystems on the planet. In these shallow, ephemeral waters, species like the Mexican garter snake once carved out a precarious ...

The narrow-headed garter snake is a nonvenomous snake found in and near the cool, clear headwater streams of the U.S. Southwest. With its stripeless, grayish-colored body, it has been called “drab” in ...

Why are bats dying in North America? An estimated 6.7 million bats have died since 2006 because of an outbreak of white-nose syndrome, a fast-moving disease that has wiped out entire colonies and left ...

Three vital provisions give the Act its teeth. It’s “citizen-suit” provision lets public-interest groups and individuals petition and sue sluggish federal agencies to make sure the Act protects ...

Ocean acidification strips seawater of the materials that marine animals — such as corals, plankton and shellfish — use to build their shells and skeletons. This can stunt growth or cause deformations ...

The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems. Biological diversity, often shortened to biodiversity, is ...

The U.S. transportation sector is responsible for about a third of our country’s climate-damaging emissions. In California transportation is the leading source of greenhouse gas pollution, accounting ...

The American pika — a small, herbivorous, conspicuously cute mammal related to rabbits and hares — is adapted to the cold climate in high-elevation boulder fields and alpine meadows in the mountains ...

Hellbenders may not be pretty to everyone, but these strictly aquatic salamanders are as interesting as their awesome name implies — and they grow up to 2 feet long and sometimes top 4 pounds, making ...