Some Common Cold Water Pond Fish
Green Tench, Golden Tench
The usual wild Tench is a dark green, almost black, but this golden variety has been bred for ornamental ponds. Their ability to live in poorly oxygenated water makes them ideally suited to ponds in localities where good water condition is difficult to maintain.
Mainly bottom feeders, eating larvae and daphnia. Whilst young, algae is consumed.
A very attractive, salmon-orange coloured fish, which is very active. It swims near the surface of the water, and can be seen constantly in the Summer.
This lively and attractive fish makes a good pond fish. It prefers a muddy bottom. Breeding is difficult, but when it occurs, it takes place amongst marginal plants in early Summer, at which time females develop a long fleshy tube (ovipositor) from the genital opening down which the eggs are passed. In the wild the eggs, numbering from 40 to 100, are deposited in the freshwater mussel’s gill chamber, where they are fertilized by the male, and hatch 3 weeks later. The young then leave the mussel after 2 to 3 days, when the yolk-mass has been absorbed. In your pond it is unlikely that natural conditions can be simulated, but fish can be induced to spawn in artificially contrived `mussels’. If ‘mussels’ are not made available the ovipositor shrinks and no eggs are laid. Food for the bitterling comprises plankton, daphnia and tubifex worms.
Rudd, Golden Rudd
Normally a shoaling fish frequenting warm lakes, and slow moving rivers. Will keep well with other fish of the carp family, and will hybridise with roach or bream. Will eat small amounts of pond weed, water milfoil, stonewort and some other plants, but larger specimens are wholly carnivorous. Other food includes snails, larvae of the mayfly and caddis fly plus bloodworms and daphnia.
Sexually mature after 3 or 4 years (around 5 inches). Spawning takes place April/June, when water temperature around 65°F. Eggs deposited on submerged plants, hatch in 8 to 15 days.
What a beautiful fish this is! It prefers a thickly planted pond with a muddy bottom. Food comprises water fleas (daphnia), midge and other larvae, worms and small snails. Spawning occurs at around 70°F in shallow water where a very large number of eggs can be laid, over a period of weeks. The fry which hatch from the adhesive eggs after 3-8 days are sustained by a yolk-sac for a further 2-3 days before floating to the surface. Fry can be fed on algae and very small daphnia.
Growth can be rapid, sexual maturity is reached at 3-4 years and weight can be up to 1-1/2 – 2 kg. At this time. Poorly oxygenated waters are tolerated, and it does well in very warm areas.