One of the biggest mysteries of evolution is how species first developed complex vision. Jellyfish are helping scientists ...

For Japanese marine photographer Ryo Minemizu, some of the world's tiniest creatures prove to be the most awe-inspiring.

A group of volunteers in Hawai'i recently worked to eradicate invasive jellyfish from a historic local fishpond.

This threat applies to at least a quarter of the species in six different classes, including arachnids and chilopodans (centipedes), as well as anthozoans and hydrozoans (marine invertebrates related ...

The survival of more than 3,500 animal species is in jeopardy ... (centipedes), as well as anthozoans and hydrozoans (marine invertebrates related to jellyfish and corals), according to the ...

as well as anthozoans and hydrozoans (marine invertebrates related to jellyfish and corals). Smaller percentages of other classes' species are also directly at risk from a warming climate.

In the 1990s, Christian Sommer, a German marine biology student, collected these tiny jellyfish while studying hydrozoans in Rapallo ... makes it unique among known animal species. Immortal jellyfish- ...

Although the transparent blue blobs resemble jellyfish, velella velella aren’t actually jellies, according to the National Park Service. They’re hydrozoans — a species related to jellyfish ...

After the arrival of thousands of barquetes de Sant Pere, as they are known in Mallorcan - Saint Peter’s sailboats or to be more precise ‘velella velella’, a jellyfish-like hydrozoa species - was ...

On Saturday, the Repic beach in Puerto Soller was covered by thousands upon thousands of 'velella velella', a jellyfish-like hydrozoa species known in English, among other names, as 'little sail'.

scientists divide the more than 4,000 species known as jellyfish into four groups: Scyphozoa or "true" jellyfish, Cubozoa or box jellyfish, Staurozoa or stalked jellyfish, and Hydrozoa.