"to his chagrin I call him H2O"


Duncan is punning on watery and fishy themes again with the the two nicknames given to Henning Hale-Orviston by his son and wife.



Jumping Salmon
Creative Commons Attribution Share AlikeJumping Salmon - Credit: Jerome Charaoui

Gus calls him H2O which is the chemical symbol for pure water and Ma calls him Hen which Gus informs us is common usage among fishermen of the US Northwest for female steelhead



[this picture was labeled steelhead in the Wikipedia article and in one place on the license page though its title claims salmon.  They're closely related so I'll  let this stand for now as it's so gorgeous. ]