You turn your back for a few minutes...

So, have a small shrimp tank on my desk at work. I asked in General Office who I would have to speak to for permission to keep a small tank. They advised me that the partner in charge of my floor would be the one to ask. I asked him, and he said he had no problem with it (while giving me the now traditional 'the librarian is crazy, don't make any sudden moves' look).

So I got a teeny tank. It has no filtration or anything else, as 1) the tank

is too small to fit a filter into without taking up a third of the tank, and 2) it would make noise, and as this is the worlds quietest open plan office (our kitchen area is referred to as The Big Brother Kitchen as everyone can hear everything said in it), noise is not a good thing. I'd get...frowned at.

And when I say this tank is teeny, I mean it's *really* teeny. About 4 litres. It has Java Moss, and a moss ball in it, on top of hermit crab micro sand. I wasn't really expecting much of it, hopefully just the shrimp to survive, if I was lucky. This is far smaller than is usual for shrimp, especially without filtration, but I thought I'd try my luck. If things didn't go well, I'd add a quiet filter and brazen it out with my colleagues.

It's got 5 Cherry Red Shrimp in it, and I decided after a week or two that it needed some little snails too, as the chrimp aren't able to get the algae off the sides very well, so now it's also got 5 red ramshorns snails in there too. They immediately set to work and now the sides are lovely and clear.

The shrimp seem very happy - every few days I come in to yet another 'ghost' shrimp lying on the tank floor, which is the shed remains of a moult. The shrimp can only grow through moulting, so periodically they have to split off their shell and ping themsleves out of it. To the ghost shrimp are evidence that they're growing well.

The Java Moss (a slow growing plant) is sprouting, and the shrimp love hiding in it and feeding on the biofilm that growns on it.

My colleagues love the tank, and ask for regular updates on how things are in it. It's quite amusing - the variety factor of having something living in the office!

And...

There's a breeding frenzy going on in there!

The snails have laid eggs on the tank wall (hard to show in this photo - the clear disk on the side has half a dozen little blobs embedded in it), and I think some of them have already hatched, if the tiny little blobs slowly moving along the tank walls are baby snails. I'll need to remove them when they get to a size I can grab them, as these snails are hermaphrodites, so they'll just keep on breeding madly!

The female shrimp have matured, and now I can see yellow 'saddles' on them, which are actually the eggs maturing in their ovaries. If I'm lucky, they may even breed soon. Cherry Red Shrimp don't have a larvae stage - when they're born, they're perfect little replicas of adults.

The females are the fully red ones, the male in these photos is the lighter red with whiteish sides.

There's also small things pinging around the tank. I think these are probably Daphnia / water fleas that could have arrived with the water the snails came in. They can get into the algae between the sand particles that the shrimp might have missed. They're no trouble, and nothing in there will eat them, so they should be happy too.

It's just a desktop soup of crustacean sex.