Relevancy, thy name is Flytrap. Welcome to the first of our "Dear Facebook" editorials, in which we put the entire Facebook community on a pedastel, throw topical questions at it and make up semi-ludicrous answers till somebody's lawyers ask us nicely to stop.

This week's topic is fish. Or to be more precise, fish games. Heavyweight social gaming operator Zynga made its own contribution to the subgenre - Fishville - over the weekend, to compete with such popular piscines as Reef Life and Happy Aquarium. Slide launched another - Top Fish - only yesterday. Quite frankly, we're starting to wonder.

Without further ado, then - Dear Facebook: why are you obsessed with fish?

1. Because all Facebook users are actually penguins.

One of the dafter side effects of massive global over-fishing is that penguins now find it easier to breakfast on virtual cod than the old skool variety. Mmmmm. 50 by 50 pixels of animated scale texture. You'll want ketchup on that.

2. Because we associate tropical fish with holidays.

Not much explanation needed here, shirley? Every sim - indeed, every game - is a "holiday" of sorts, catering to our basic human escapist urges. By allowing users to fiddle with various specimens of brightly coloured aquatic fauna, publishers are simply providing outlets to those who can't afford tickets to the Caribbean.

3. Because fish - unlike mobsters, Orcs, vampires, farmers, etc - don't spend most of their time killing stuff.

Ooh, dubious reasoning there. Ever watch Blue Planet? Although you could certainly argue that Facebook-based fish are peaceful critters. We have yet to see a Barracuda zeroing in on a crowd of minnows in Happy Aquarium.

4. Because fish are novel.

It's just a phase, in other words. The market is bored with cuddly farm animals, cafes and crooked gangsters. Fins and tentacles are in; hooves, soya lattes and Tommy guns are out. Next year we'll probably be up to our necks in amateur bee-keeping sims, or something.

5. Because down where it's wetter, dat's where it's better.

A matter of empirical fact, you know.

6. Because playing a Facebook sim is exactly as enthralling as watching fish swim round a tank.

Did I type that out loud?

7. Because Zynga's in cahoots with Birds Eye.

Hold on, I think I hear the lawyers coming.

(Feel free to post your own hypothetical responses below.)