Ishmael describes the behavior of whales when they gather in herds. There are two types of whale "schools," divided by gender.
The all-female schools, which Ishmael describes as harem-schools, are often accompanied by a single, huge male, much larger than any of the females, which Ishmael calls the "Grand Turk."
The harem-school rambles around through different waters, and the Grand Turk protects the females from any obnoxious young male whales who think they're going to mate with one of them.
Sometimes the males seem to duel for love of the females by jawing at each other.
The Grand Turk mates with many different females, but doesn’t care at all for his children.
Eventually, in extreme old age, the Grand Turk disbands the harem entirely and becomes a lone whale.
At this stage in the Grand Turk’s life, the fishermen don’t hunt him much, because his oil isn’t plentiful enough to make it worth the trouble.
The Grand Turk is also called the "schoolmaster" of the group of whales... although Ishmael thinks it's a pretty immoral schoolmaster who’s always sleeping with the students. Where did he get this stuff?
The all-male schools of young whales are much more violent and hot-headed and very dangerous for whaling ships to encounter.
The other difference between the schools is how they behave when one of them is attacked—the males abandon their fellows to their fates, wile the females cluster so closely around an injured schoolmate that they often become victims, too.