The goldfish apparently has an identity crisis. It is a fish with a single name, but many guises, some as extreme as to suggest that they belong to another species.
The goldfish has very humble beginnings, with its first natural mutation simply being a change in its colour. It dropped its brown demeanour for a yellow finish, and endeared itself to those who had initially reared it for food.
What has emerged since from such chrysalis-like beginnings has been a string of varieties with wild permutations in colour, shape and form. Even though these varieties do not resemble each other, it is easy to be carried away into thinking these are different species. Not so. So packed with gems were first goldfishes' genetic treasure chests that hidden in such meager packaging were the many fancy varieties based on the same theme. Coming at it biologically, all of the varieties of goldfish can be successfully interbred to produce viable offspring, which will continue to amaze and confound in the sheer diversity of varieties produced.
Over the years, breeders have concentrated on producing different varieties of goldfish by changing any of the physical features. Whatever the goldfish's feature, it has probably been mutated to produce a different variety at one time or another. Eye shape and position, body colouration and scalation, body shape, fin size, shape and number have all been changed to produce a different variety of goldfish.
The different varieties of goldfish can be divided quite practically into two groups. Those that will live and thrive in a garden pond (including over wintering) and those that will not, and are best kept in an aquarium full time or brought in for the pond to overwinter inside. This latter group are referred to a fancy goldfish in the trade and will generally be displayed for sale in aquaria rather than open topped troughs and tanks.
1). Goldfish varieties safe for the pond.
There is a general rule of thumb in recognising whether a goldfish variety is suitable for a pond. If it resembles the overall typical shape of a goldfish, but shows differences in colour or even fin length, then it is likely to be hardy enough to tolerate UK winters and fast enough to compete for food in a pond.
Examples of these fish include:-
The common goldfish.
Typically a very evenly pigmented fish with short and sturdy fins and tail. Often available in a number of different colour variations where other colours such as white and black appear on top of the original golden colouration.
The Comet goldfish.
These have been bred for a long tail fin, which in larger specimens may be half the length of the whole body. Comets are rarely one colour, but will regularly display white and red patterns that are more pronounced when viewed from the top. Furthermore, the comet's colour is usually more red than gold.
Shubunkin.
Compared with the other previous goldfish varieties, the Shubunkin is extremely distinctive in its colouration, with much variation occurring between individual fish. Rather than being gold, Shubunkins are blue where the colour appears to come from beneath the scales rather than from above as in the traditional goldfish. The Shubunkin has a black and orange mottling set on the bluish 'mother of pearl' like background. I remember when I first saw Shubunkins, that I was put off because their imperfect and random patterning made them appear diseased!
2). The fancy gold fish.
These are more distant relatives of the goldfish and been selected to exhibit some extreme physical features. These fish are so in-bred that they lack the vigour of their distant relatives. They will not tolerate a British winter in a pond.
Examples of these fish include:
A. Orandas
When viewed from above, their double-tail looks like a butterfly. They can adopt a variety of colours, including calico, which resembles a Shubunkin.
B. Blackmoor
Similar in shape to an Oranda, this black fish has bulbous eyes that project from the head.
C. Lionheads
These have a development on their head similar to the mane of a male lion. They too have a twin tail, but lack a dorsal fin.
D. Bubble Eyes, Pom-Poms and Celestials
These are all fancy goldfish in the extreme. Where breeders have selected for wild variations in head and eye developments.
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