A team of researchers in Australia have imaged fossilized soft organs of early jawed vertebrates for the first time, finding that our ancient fish ancestors’ hearts, livers, and stomachs are strikingly similar to ours.

A high-quality genome sequence for this versatile insect will likely aid eco-evolutionary research.

Threatened and endangered species were among the dead, likely poisoned overnight by a chlorination system used to decontaminate the animals’ tank water.

A fossil analysis suggests that the yunnanozoan, a wormlike fish that flourished around 520 million years ago, sported structures that were the precursors of the head and jaws of modern vertebrates.

A study yields insights into how predator-prey dynamics may shift with climate change, but many questions remain.

The fish species is separated from mammals by hundreds of millions of years of evolution, yet its seemingly primitive brain can handle many of the same elaborate visual tasks.

The roar of nearby boat engines alters how fish care for and protect their young, resulting in fewer successful nests and smaller offspring, a study finds.

Tourist photos help identify endangered manta rays and highlight the efficacy of recovery efforts at Komodo National Park.

Once thought to be silent, fish turn out to produce a range of vocalizations—so polluting the oceans with noise could pose a danger to them.

These tiny reef fish harbor luminous bacteria, and the chromosome-level assembly of the species’ genome may facilitate the duo’s use as a vertebrate model for symbiosis.

Scientists find that two species can be trained to distinguish quantities that vary by one.

Researchers determined the season during which the meteor struck by studying the bones of fish excavated from a contentious field site.

The Scientist spoke with cognitive neuroscientist Ronen Segev about how he taught goldfish to maneuver a moveable tank over land toward a visual target.

Moving collectively on the water surface could help protect schools of fish from being eaten by predatory birds.

Shared features, such as thick, slimy skin and a throat filled with teeth, suggest that medusafishes are all related.

The high-quality genome sequence sheds light on the colorful nature of these popular aquarium fish.

An analysis suggests that a commercially important mass migration of fish may have no real adaptive value.

A modeling study estimates that by drastically reducing fish biomass over the past century, industrial fishing may be affecting ocean chemistry, nutrient fluxes, and carbon cycling as much as climate change.

A study of feeding behavior suggests the fish feed differently in front of their partners—a behavioral feature also found in primates.