If you have visited us over the past month you will have noticed our brand new outdoor aquarium full of indigenous species including; Silver Rudd (Roach), Sticklebacks, Mirror Carp, Ghost Carp, Gudgeon and Green Tench.
We cannot, of course, forget also the variety of molluscs and plant species such as Swan Mussels, Ramshorn and Trapdoor Snails that are in the aquarium. At first, whilst cycling the tank, the water was murky. We popped a couple of swan mussels in and within a week it’s crystal clear. These guys filter on average 10L of water a day EACH. That’s a lot of floating particles taken away from the water. They will also mooch about, putting out their foot and pushing themselves around the bottom and will often burrow into the sand or sediment present. This sediment, whether it is a collection of dead plant matter, fish waste or just things that have fallen into the pond, gradually develops pockets of phosphates and nitrites that left undisturbed can grow to lethal levels for the fish. The mussels and other burrowing snails displace these bubbles, breaking them up and letting the gas rise to the surface where it will be dispersed into the atmosphere.[youtube https://www.youtube.com/watch?v=p3s5xnvoSTQ&w=420&h=315]
The tank itself is more about demonstrating an ecosystem than just a display. The way each fish and animal deals with the environment is infinitely fascinating. Sticklebacks front up every other fish, no matter the size, and are always territorial whereas gudgeon and green tench scoot about the bottom and in and out of weeds picking up detritus as they go.
Mirror Carp and Ghost Carp tend to stay in small groups and hang around the plants and the surface as the Rudd and Orfe shoal in great glittery masses up and down the length of the 8ft tank.
It’s important to us that we show the diversity and beauty of native fishes but also the idea of an ecosystem in either a pond or aquarium. Clinical trials have demonstrated that the increased variety of species in a pond or aquarium is positively correlated with decreased stress, heart rate and blood pressure as well as just being more interesting! (Well maybe that last one is more opinion than fact!)