The fish weighs about 14 kg, and is  probably the biggest goldfish in the world.  The fisher, named Raphael Biagini, needed about 10 minutes to get the goldfish ashore.  Before he started fishing that day, some colleague fishers told him there’s a giant goldfish in the pond and that they have been trying to catch him the last six years.

“We didn’t know what bit in our fishing line, but we knew it was big.  The fish was a good fighter, but not good enough…” says Biagini.  Luckily the 30-year old fisher from Montpelier released the fish after a photo session.

I guess this beautiful goldfish’s quiet life is over now everyone knows where he is at…

Most aquatic snails are tropical and should not be kept with goldfish.  It is particularly worth noting that apple snails are often sold as ideal tankmates for goldfish.  They are not, for two reasons: one, they are tropical snails that prefer the water temperature to be about 4 degrees celsius warmer than is healthy for goldfish; and two, goldfish will eat the ends of their antennae and eye stalks.

There are only two snail species that can be kept with goldfish, and they are the ramshorn snail and the pond snail.

The ramshorn snail has a shell in a flat coil shape that can be bright red, pink, blue, black, green, brown, orange or yellow.  It can also have stripes or spots in combinations of these colours.  The red and pink ramshorn snails have actually got very low pigment levels, allowing their unusually (for a snail) red blood show through.

The pond snail’s shell is more like the shape of a twisted cone, broad at the opening and ending in a point.  The variety of colours is not as wide as the ramshorn, but it can have a range of patterns and light and dark colours.

The main benefit of aquarium snails is their appetite for algae.  They will clean the glass, stones, ornaments, pumps and anything that has a surface algae will grow on.  This saves a lot of time and effort, and generally means that weekly water changes don’t need to be accompanied by scraping the glass and siphoning off the scrapings.

One thing that is very important to snails is the pH level of the water.  pH is a measure of the acidity or alkalinity of the water.  Although goldfish are happy enough with anything between pH6 and pH8, snails need it to be over pH7.  Anything below pH7 is acidic and will erode snails’ shells.

The biggest problem with aquarium snails is their capacity for breeding.  For every snail in a tank at the start of a year, 500 can be expected at the end of the year.

The solution to such a problem in most animal species would be to get either two males or two females to prevent breeding.  This won’t work with aquarium snails because both ramshorn and pond snails are hermaphrodites.  This means that each and every one of them has both male and female reproductive organs, and is therefore able to mate with any other snail of the same species.

The obvious solution to this problem would be to keep only one snail.  Unfortunately that won’t work either.  Both the ramshorn and the pond snail have an ability known as auto-fertilisation.  This means single snails can produce offspring without a breeding partner.

If this happened in an aquarium, all snails would be exact clones of the parent that auto-fertilized.  This is obviously not ideal, but in the wild it is a technique used by snails to quickly stock a body of water that has no snails in it.  Other unrelated snails will most likely arrive to mix in some new genes and prevent genetic problems.  Both species of snail can survive out of water, and do so to get to new ponds and lakes.

Interesting stuff.

To start with, there are two basic colour types: metallic and calico.

Calico

Calico is the name given to the colour pattern most commonly found on shubunkin goldfish.  It is an irregular pattern of orange, yellow, red, black, brown, blue, violet, pearl, white and/or silver.  As long as there are three or more of these colours in a random pattern, the goldfish is calico.

Another feature of calico colouring is that some of the scales are shiny, some are translucent, and some are velvet in appearance.  The shininess of goldfish scales depends on the amount of a substance called guanine present in the scales.  The more guanine, the more reflective the scale.

The blue and violet colours that can be found in calico goldfish are actually black pigments deep under the skin that appear coloured when viewed through the pearly coloured skin.

Metallic

The term metallic is slightly misleading, as it does not necessarily mean reflective all over.  Metallic coloured goldfish can have shiny or velvety scales.

Metallic colouring is divided into two types: self-coloured and variegated.

Self-coloured means nothing more than the same colour all over.  The colour can be orange, yellow, red, black, brown or blue.

Variegated simply means that the goldfish has more than one colour, and both sides of the fish are almost exactly the same pattern.  As well as the list of colours available in self-coloured fish, silver and white can be present in variegated fish.  A good example of variegated colouring is the redcap oranda.

Almost everybody knows it, but plenty of people do it.  Goldfish that live in a bowl do not get enough oxygen, are exposed to disease, and usually die young.  If they are unlucky enough to survive into adulthood, they will be too big for the bowl and suffer from deformities.  It is cruel.  Don’t do it.

2. Put in a blender

A fairly old story, but nonetheless shocking.  An artist called Marco Evaristti had work displayed at an exhibition in the Trapholt Art Museum in Kolding, Denmark in 2003.  His artwork was a blender with 2 live goldfish in it, and an open invitation to anybody to turn the blender on.  Somebody did, liquidising the goldfish within a second.  Mercifully it was a quick death, but unnecessary, crass, attention-grabbing and cruel.

3. Sealed inside a novelty keyring

Street traders in Qingdao, China have been selling novelty plastic keyrings with a little bit of water and a goldfish inside.  The keyrings are made of transparent plastic with a picture of Huanhuan – an Olympic mascot – printed on it.  Needless to say each goldfish has little or no room to swim in, hardly any oxygen, and is destined to die of suffocation.

Before going on to different fish species, it is worth repeating the fact that narrow-bodied and fat-bodied goldfish varieties should not be kept together.  The narrow-bodied goldfish such as common, comet and shubunkin will have eaten all the food before the fat-bodied ones (most fancy goldfish) realise it’s feeding time.

Also, before introducing any new tank mates, make sure to quarantine them properly beforehand.  Non-goldfish tankmates for goldfish have the potential to cause enough problems already without disease being one of them.

Another thing to be aware of – if the other species of fish can fit into a goldfish’s mouth, it will end up in a goldfish’s mouth.

Hillstream Loach

The hillstream loach is perfectly adapted for latching onto a surface and facing into a strong current.  Their natural habitat is fast-flowing streams, and they have a perfectly streamlined body.  Their perfect tank environment has a strong pump creating a current.  Because of this it is impossible to keep both goldfish and hillstream loaches in their ideal conditions.  Goldfish are not built to deal with a constantly strong current.

Like all algae eaters, they need to be fed away from the goldfish.  The best plan is to feed the goldfish at one end of the tank, then drop in some sinking food for the loach at the other end.  A varied diet is best for them, but algae tablets and sinking pellets should form the basis of their diet.

One nice feature of the hillstream loach is its ability to change colour according to its surroundings.

Weather Loach aka Dojo

The weather loach is a slender, fast fish that can grow up to 6 inches long.  They scavenge around the bottom of the tank, and thrive where there is fine gravel to root around in.

They can dart extremely quickly and have been known to leap out of goldfish tanks.  Obviously this is fatal if not witnessed.  It is a good idea to have some sort of cover over the water to prevent this, and only to uncover as much of the surface as is necessary when performing any aquarium maintenance.

When weather loaches are not sitting at the bottom of the tank, they do enjoy swimming in and around tank ornaments.  These ornaments can cause injury to fancy goldfish that have protruding eyes.

Corys

Corys are a type of catfish, and there are over 10 common cory species.  They usually sit close to the bottom of the tank, not doing very much.  Occasionally they will go for a swim, but will usually sit about doing very little.

Most cory species sold for goldfish tanks are not the type of catfish that can grow bigger than a man.  In fact they will not usually grow beyond 3 inches.

Like loaches they are bottom feeders, and need sinking food chopped up small.  They generally get on well with goldfish, but if not fed properly will suck the protective slime coat off goldfish.  This is a disaster if it happens.  The slime coat protects against all manner of goldfish illnesses and diseases, and its loss can be catastrophic for goldfish.

White Cloud Minnows

White cloud minnows are small fish that grow to about 1 inch long.  They are social fish and should be kept in shoals rather than as individual fish.  This feature makes them an attractive addition to an aquarium.

They will eat the same food as goldfish, and do not need fed separately as they can swim fast and can compete.

One thing they do like is a hiding place somewhere in the tank.

The main problem with white cloud minnows is their size.  When goldfish grow big enough, they will almost certainly eat them.

Other

There is one other species of fish that is often said to compatible with goldfish – the chinese algae eater.  However, it is a tropical fish and although it has been kept with goldfish with moderate success, it is not recommended.

The only other species that can be kept with goldfish are snails.  The most attractive one (subjective of course) is probably the golden apple snail.

In Chinese there are two words that are spelt in English as yú. To the untrained ear they sound exactly the same, but one means fish and the other means bounty or surplus.

Therefore goldfish became a symbol of surplus and wealth, and a gift of goldfish is a blessing in the hope of good fortune.

The association of goldfish with good fortune is reinforced in legend. One tells of a period of drought ending when the world’s first goldfish jumped out of a well. Other chinese myths have goldfish present at the beginning of time.

In art, paintings of fish have been found on Chinese artifacts dating from around 8,000 BC, and goldfish can be found in Chinese art to this day. Not only do these images represent or bring abundance and success, goldfish represent the notion that it is possible for anybody to achieve whatever they want.

Chinese brush paintings of goldfish perfectly capture the lightness of the fins, the lines of the body, and the life-force of the animal in a few simple strokes.

In Feng Shui, a painting of goldfish is regarded as having the same effect as an actual goldfish tank by practitioners.

So for at least 1,000 years goldfish have been part of one the most ancient, mysterious, fascinating and successful cultures on earth. No wonder they are such a welcome feature in homes and businesses throughout the world.

So if a goldfish is suffering from an illness that cannot be cured or even treated, what is the best way of ending its suffering?

Some methods of goldfish euthanasia are based on anaesthetic overdose. Others are based on rapidly increasing carbon dioxide levels in the water, thereby suffocating the fish. Some methods use extremes of temperature. The old fashioned (and still widely used) way is to behead the goldfish.

Finquel

Finquel is an American brand name for a fish anaesthetic called MS-222. An overdose of this drug is considered a very humane method of goldfish euthanasia. The problem is getting your hands on MS-222 and administering the correct dose. It is also important to note that MS-222 makes water acidic. If this is not buffered i.e. if the acidity is not reversed, the fish will die a painful death. The easiest way to do this is to add baking soda in equal measure to the MS-222. Please note, this is unrelated to the baking soda method of goldfish euthanasia. The suggested dose is half a teaspoon of MS-222 with half a teaspoon of baking soda for every 4 litres of water.

Clove Oil

Using clove oil to anaesthetise a goldfish is a more accessible form of anaesthetic overdose. Indeed clove oil is also known as eugonol, a common fish anaesthetic used by vets. Fill a separation tank with 4 or 5 litres of the goldfish’s tank water and place the goldfish in it. Then fill a jam jar half full of the same water. Add a teaspoon of clove oil and shake it until the water turns white. This will require a bit of effort as clove oil does not mix readily with water so it needs to be shaken. Pour this mixture into the separation tank and wait for the goldfish to lose consciousness.

Isoflurane

Another veterinary fish anaesthetic that is not generally given to members of the general public because it is a substance that can be abused by humans.

Clove Oil and Vodka

A variation of the clove oil and water method. The idea is for the clove oil to dissolve in the vodka, which is then easily dissolved in the tank water. This method is not recommended because it is very hard to get the correct dosage. If it is not correct, the vodka burns the goldfish’s gills and caused extreme pain prior to death.

Baking Soda

When mixed with water, baking soda produces carbon dioxide. To use this method of goldfish euthanasia mix 10 teaspoons of baking soda with a litre of water then add the mixture to a separation tank with the goldfish already in it.

Alka Seltzer

Works exactly the same way as baking soda – it increases carbon dioxide levels in the water. Use one tablet per 10 litres of water, then add the goldfish.

When using any of the anaesthetic overdose or carbon dioxide poisoning methods leave the goldfish for at least ten minutes after the last sign of life.

Beheading

This is a quick and pain free method of goldfish euthanasia. Until relatively recently it was the only method. However, there are 2 good reasons not to dispose of a goldfish this way: firstly, the fish will experience obvious discomfort and stress in the moments between being taken out of water and getting its head removed, and secondly it can be very messy.

Freezing and Boiling

Do not use either of these methods. They are now thought to cause extreme pain and slow death.

Summary

So to get back to the original question – if a goldfish is suffering from an illness that cannot be cured or even treated, what is the best way of ending its suffering? There lies the problem. There isn’t a best way. For a start we are talking about killing goldfish. Never nice.

Anaesthetic overdose is, on the face of it, the most humane method of goldfish euthanasia. However on a practical level it may not be possible to obtain veterinary anaesthetic in a reasonable timeframe (or at all). The carbon dioxide methods are quite likely to cause a degree of suffering simply due to the fact the goldfish is being suffocated. It’s bound to know something is seriously wrong. The reasons against beheading are the same. Freezing and boiling are out of the question.

So the most important thing is probably not how the goldfish’s suffering is ended, rather how great that suffering is. If you know your fish is experiencing high levels of pain and discomfort and has a poor quality of life with no chance of recovery, you are doing the right thing by disposing of it humanely.