18 Channels on the TV, and the best entertainment in my flat is the aquarium. Since I installed the four yabbies, they have settled in very well. They each have a plastic or aluminium hole to crawl into and I have just introduced some weed to help keep the water fresh. Yabbies make a hell of a mess so I also use flocculant to remove the colloidal murk and change the filters frequently because they clog up pretty quickly. Since the filter cartridges are so expensive, I went to the haberdashery and bought a roll of orlon fibre (used for quilts and duvets etc) for the princely sum of 80 cents for 20cm by 1m, and I picked up a bag of activated charcoal from the pet shop for about $8. I now make my own filters up for a hundredth of the cost of a cartridge.
As a result, the water is now crystal clear, and the yabbies are slowly turning from cream yellow to blue, as predicted. I have been trying to photograph them but I am having problems filming from outside the tank because of reflections in the glass, or shadows from the flash. If I put my waterproof camera inside the tank, they retreat into their holes whenever I try to shoot. As soon as I get a good shot I shall post it. I will figure it out.
The Gambusia I had in the tank are now reduced to a mere few. They have learned not to sleep on the gravel any more, but were decimated before they figured it out. They sleep at the surface or amongst the weeds now. The crayfish have taken to climbing the weeds so I guess that is no longer a safe place. It seems only justice that these nasty little invader fish, which have done so much ecological damage to Australian wildlife in ponds and streams, should suffer at the hands (or pedipalps) of native crustacea. When I first captured them, I knew it would be unlawful to release them again, and did not intend to do so. I was trying to figure out an entertaining yet humane way to kill them. Then I discovered that in fact even keeping them in a tank is unlawful.
Under the Fish Resources Management Act 1994 you must not do the following with any noxious fish:
- keep, breed, hatch or culture them;
- have them in your possession;
- consign or convey them;
- release them into any waters; or
- put them into a container or receptacle in which they might remain alive.
I was about to flush the Gambusia down the loo when I had the offer of yabbies caught from a private dam. I decided to see how they would interact. The score so far is definitely in favour of the crustaceans. I count the fish every day. On Sunday there were only nine left. This morning there were six. If any are left next Sunday, I shall humanely dispose of them.
Other than Gambusia, the omnivorous and voracious yabbies like ordinary fish food, and the occasional morsel of chicken breast or minced meat. I mostly feed them whole green beans or salad greens blanched in hot water and squeezed so that they sink. It is most entertaining to see the yabbies scuffle with each other over the beans, then once they have sorted themselves out with one each, settle down to eat in their odd crustacean way, grasping the bean with their claws, picking at it with maxillipeds and stuffing it into their mouths.
I think they are getting used to me.
PS 5 Gambusia