Why and how Killifish came to exist.

Belonesox, the "Pike livebearer". Esox is the genus for Pike. Not related but in the 18th century when the name was coined they looked similar and in that era that's all that mattered. Around the 1950s we woke up to the idea the family relationships matter, appearances mean nothing so we quietly switched the bases od classification to what is called "Phylogenetic" relationships, that is, based on fish having common ancestors and no just because they ended up looking the same. This is called "convergent evolution" - where two things end up at the same place despite not being related at all. "divergent evolution" is where on forms evolves into one ore more different forms, and is one way new species occur (on geological time scales over thousands and millions of years)

Breeding to improve your killifish II

Hypothetical evidence improved selenium status may improve reproductive issues with problem fishes


The story of the first Blue Gularis in captivity (with photo!), the "Yellow Gularis" and a three other killifish kept in the first decade of the 20th century, as told by Paul Arnold.