The whale=fish thing is also an old joke about catholics. Back when one could not eat meat on fridays, all sorts of water-living mamals were declared to be "fish" for purposes of eating. So a new world protestant author in the 1800s is pointing a critical finger at oldworld religion and science.

We have lost knowledge of such nuance, like rewatching MASH or Trek and missing the religious and racial messages that made them so controversial then but banal today.

> Back when one could not eat meat on fridays, all sorts of water-living mamals were declared to be "fish" for purposes of eating.

Like what, seals? Otters?

Something tells me that otters were never passed off as "fish".