What's the difference between six little boys burning ants with magnifying glasses in the school playground and six big boys dragging a blue marlin to its death in the South China Sea (as reported on the front page of your Sunday Morning Post last week)?

No, really; what's the essential difference, other than that the marlin is likely to find itself on an endangered species list soon while ants are not? The fisherman will say, of course, that fish must die to feed people, so he may as well have a bit of fun in the process. But this poor creature was tortured for more than three hours before it perished.

Fish feel no pain, the angler may counter. According to a recent study, that may be true: fish do appear to show "little effect" from injuries and toxins, says Professor James Rose of the University of Wyoming, in the United States. But fishermen fished even when studies suggested the opposite (as many still do). Isn't the worrying thing here that, in the 21st century, some of our own species still kill for fun?

Deep-sea anglers cannot even hide behind the excuse - used by fox hunters in Britain and big-game chasers on private African reserves - that without their investment in the pursuit, their quarry would be wiped out by farmers and/or poachers.

That schoolboys like to immolate ants suggests killing creatures is an inherent male human trait - but so, you might argue, are enslaving other people and subordinating women. Can you imagine the Post running a story lauding the capture of slaves or the beating of women by six hedge-fund managers?

Attitudes will probably change. And with luck, there might even be a few marlin left to feel the benefit.