Whalers called a lot of things porpoises. Sometimes they were dolphins. Sometimes they were mahi mahi.

↓ Transcript
Panel 1 [Josiah Ripley and Frances Goldwhit are working to get the fish over the bulwarks as Samuel Nelson turns to address Adelaide.]

SAMUEL:
S’a porpoise

FRANCIS:
It changes colors when it dies. Would the lady like to see?

Panel 2 [Adelaide, frowning slightly, opens her book again while still speaking to the men.]

ADELAIDE:
That’s quite all right.

Panel 3 [Lawrence peacefully sweeps in the foreground as the group of men haul the flailing fish up on deck and Adelaide returns back to reading aloud]

Panel 4 [Same shot, only now a scream is coming off camera. Lawrence is looking up in alarm, as is everyone else in the background]

JACKSON:

Ahhhhhhh—-(thud onomatopoeia)