A perfect fish in the evolutionary sense, the broadbill swordfish derives its name from its distinctive bill – much longer and wider than the bill of any other billfish – which is flattened into the sword we all recognize. And though the majesty and...

The history of biology is populated by numerous model species or organisms. But few vertebrate groups have aided evolutionary and ecological research more than the live-bearing fishes of the family Poeciliidae. Found throughout tropical and subtropic...