A new freshwater dolphin from Brazil has been described in the journal PloS ONE, and represents the first such find in almost a century.

Scientists have confirmed the discovery of the first-ever, two-headed bull shark. The study, led by Michigan State University and appearing in the Journal of Fish Biology, confirmed the specimen, found in the Gulf of Mexico April 7, 2011, was a single shark with two heads, rather than conjoined twins.

Japanese researchers have for the first time been able to record a real-time video of thought processes moving within a living animal’s brain, and the creature in question is a fish!

Two new, closely-related species of zooplanktivorous haplochromine cichlid from southern Lake Victoria, Tanzania have been described in the journal ‘Zookeys’.

Two new species of Parosphromenus have been described from the island of Sumatra, Indonesia.

Following the recent description of B. mahachaiensis, another new species of the Betta splendens species group from Thailand is described in the latest volume of the journal ‘Vertebrate Zoology’.

New research published in the open access e-journal ‘PLOS One’ demonstrates the learning capabilities of the giant catfish Silurus glanis, Europe’s largest freshwater fish.

Scientists have shown that male Siamese fighting fish, Betta splendens, increase the frequency at which they breathe atmospheric air during aggressive interactions.

Paleontologists from the University of Florida have discovered that the dentition of an ancient great white shark relative indicates it  probably descended from makos rather than giant megatooth sharks such as megalodon.

Biologists from the University of Bonn have discovered that the dwarf cichlid Pelvicachromis taeniatus can perceive light in the near-infrared range, a phenomenon previously considered unlikely at best and which apparently helps them hunt prey in shallow African rivers.