Scientists have discovered that one of the most unusual creatures in the animal kingdom is far more diverse and evolutionarily complex than previously known. An international team led by the University of Göttingen has reconstructed the evolutionary history of branching marine worms – rare annelids that live hidden inside sea sponges and whose bodies branch repeatedly into multiple posterior ends. Until now, only three species of branching worms have been identified. By combining DNA sequencing of museum specimens with newly collected specimens and detailed anatomical analyses, the researchers discovered ten new species and solved a long-standing puzzle dating back to the nineteenth century. The results were published in the Zoological Journal of the Linnean Society.

Symbiotic ammonia-oxidizing archaea in marine sponges are not strict specialists, but true "flexitarians": A team led by microbiologists Bettina Glasl and Katharina Kitzinger from the University of Vienna, in collaboration with partners from Australia, has shown that these microbes dine not only on ammonia but also on amino acids such as valine, leucine, and isoleucine - and presumably do that to communicate with their animal host. The findings shed new light on one of the oldest animal-microbe symbiotic relationships on Earth and point to a previously underestimated role played by archaea. The study was published in the prestigious journal Science Advances.

Salk scientists uncover new advantages and mechanisms of mitohormesis, a process where mitochondrial stress early in life leads to lasting benefits. By inducing mitohormesis in mice, researchers found they could help the heart build lasting resilience against damage from a common chemotherapy drug—and identified a molecule called citrate as the chemical messenger that carries this protective signal to the rest of the cell. The findings may help explain why antioxidant therapies to counter cellular stress have largely failed and suggest new directions for healthy aging therapies.

With their slender bodies and long front legs, Miracinonyx trumani—often nicknamed the “American cheetah”—was long thought to be a North American analog of the African big cat. But in a new study publishing September 4 in the Cell Press journal Current Biology, researchers reveal that the extinct cat was more closely related to pumas. Some populations living near the Arctic preyed almost exclusively on fish, challenging the long-held assumption that these “cheetahs” chased fast-running prey, such as pronghorns. 

A new study led by researchers at the University of California, Santa Cruz, has overturned decades of assumptions about Miracinonyx trumani, the extinct predator popularly known as the American "cheetah.” By analyzing nuclear paleogenomes and stable isotopes from fossils found as far north as the Yukon, scientists have discovered that this iconic cat was not a true cheetah, but a highly adaptable relative of the puma that specialized in eating fish to survive the Arctic.

A Virginia Tech-led study of people who feed birds in the United States and Canada found that most believed feeding and watching birds had a positive effect on their well-being. The study also identified three ways people described that connection: through emotions, engagement, and a sense of meaning.

A study investigated how ingesting expanded polystyrene (EPS) affects wharf roaches, a common shoreline scavenger. EPS-fed animals showed no significant reduction in lifespan, but their guts displayed altered expression of genes involved in chemical defense, DNA repair, and digestion. Gut microbial communities were largely unchanged, although several rare taxa were detected only in EPS-fed specimens. The findings highlight the need for a more comprehensive understanding of how microplastic pollution affects marine ecosystems.

Why do some ants help nestmates in distress while others don't? A research team from Johannes Gutenberg University Mainz and Tel Aviv University has addressed this question in a new study. The researchers examined worker ants of the species Cataglyphis niger, some of which had shown rescue behavior while others had not. The result, recently published in the Journal of Experimental Biology, suggests that the key difference lies not in body size, morphology, or the animals' energy reserves, but in gene activity in the nervous system.

A revised species inventory updates Hainan’s terrestrial mammal fauna, highlights island‑specific conservation risks and provides baseline data for regional wildlife management.