There are lots of different things that we call "fish", and they belong to lots of different taxonomic groups.  I mean, hagFISH aren't even considered vertebrates any longer.  Still, all of the 28,000 or so species that we refer to as fish all have some basic similarities, likely due to the unforgiving nature of the aquatic realm.  You can't be evolutionarily sloppy and function well in the water.  However, within the basic fish template, there's still room for a lot of diversity.  This week in Fish Biology, we'll be discussing body forms, the many ways that the basic fish design has been molded to better function in a specific role. Regardless, here's a teaser. Scientific binomials, so as not to give anything away in the common names.

What drives the...

...odd mouth of Nemichthys scolopaceus,

....the spectacular dorsal fin of Istiophorus platypterus,

...or the misshapen fins of Histrio histrio?

Is there adaptive value in the magnificent rostrum of Pristis pectinata,

...or of Polyodon spathula?















What about the greatly elongated pectoral fins of Cheilopogon melanurus,

...or pretty much anything about Ogcocephalus darwini?

Why does Chaenocephalus have yellow blood?












And, finally, what in blue blazes is going on with Macropinna microstoma?