More wonderful art from Dean Stahl of Steelhorse Studios.

Cod (Gadus sp.) and haddock (Melanogrammus aeglefinus) are related species of the piscine family Gadidae, easily mistaken for one another by fish novices.

Conger eel is actually a popular, non-technical name for various eel species, including but not limited to members of the genus Conger.

Sole is an even less concretely defined term that is variously used in different parts of the English-speaking world to refer to any number of species of flatfish, including the families Soliedae, Achiridae, Cynoglossidae, and Pleuronectidae. The Pleuronectidae include the species generally known as plaices, as well as various species known as halibut.

I know that last one wasn't mentioned in the comic, but I threw it in just for the halibut.