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A very simple guide to help you understand and take care of your sturgeon or sterlet in your garden pond.                                                      

No two ponds are the same and water parameters, fish stock numbers, feeding rates, filtration systems all cause some type of fluctuations and so this has to be factored in while reading this guide. What works for someone may not work for someone else, this is a guide and should be treated as so. 

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Water Quality Parameters Sturgeon Require:

 

PH: 6.0 – 8.5

Total hardness 50-400 ppm

Oxygen 8 mg/L minimum 

Ammonia (NH3) 0.01 mg/L

Nitrite (No2) 0.01 mg/L

Nitrate (No3) 100 mg/L

Temperature -10c – 22c (optimum 16c)  

 

Pond Size:

 

Sturgeon need a large area and the minimum should be no less than a 2000 gallon pond

Depth should always be 3ft/1m or more to help stop fluctuations and freezing in cold winters.

 

Size & Lifespan

 

Sterlet: 0.6 - 1 meter in length and life for approx 25 years

Sturgeon: 1.5 - 2 meter in length and live for approx 60 years

Huso: 5 - 7 meter in length and live for approx 100 years

 

Handling Sturgeon

 

A Sturgeon spine (back) is not very strong, and can break easily. They have no bones like most things to protect it. 

To handle a large Sturgeon with your hands, have the head pointed at you.  Do not hold the tail at this point.

Gently cup the sturgeon head in the palm of your hand. Your thumb or finger will fit in the ridge surrounding the mouth. Now take hold of the tail and lift to shoulder height. You can use a wet towel for grip on the tail which may be easier.  

The sturgeon will automatically form a "J" shape. If it struggles you are holding the head too tightly. Just your hand holding the tail and loosening the grip on the head. The head should be near your waistline. 

You can now take the weight of the sturgeon and lift it out of the pond, walk a short distance and place it in the new tank.

 

Feeding Your Sturgeon.

 

Sturgeon are carnivorous benthic feeders. Sturgeon do not eat plants.

They require a sinking high meat based protein pellet of 42% protein or more. 

Feed Sturgeon twice every day a minimum of  0.3 - 1.0% of their body weight depending on age and size. 

Some people advise to feed 3% of body weight. But this seems way too much.

Feed them with little amounts but quite often. At least twice daily and if possible feed after dusk because this is their preferred time to feed.

Signs of malnutrition in Sturgeon:

Early signs are if its head looks big compared to its body, it is under fed.

Starting to bend into a horseshoe looking shape. This too is very under fed.

 

Food Pellet size

 

2-3mm pellet for 6-14 inch

3-6mm pellet for 14-20 inch

6mm pellets and above for 20-25 inches and so on.

If you can measure their mouth width. The size of pellet they should be fed will be half the width of the mouth. 

 

If the temperature is optimum 16-20c a Sturgeon can eat every hour if they choose. Siberians will eat right down to -11c. UK winters are cold but not Siberia cold, you must attempt to feed everyday.

 

Oxygen Sturgeon Require.

 

8 mg/L is the minimum Sturgeon and Sterlet require for good quality of life.

 

Dissolved oxygen and temperature chart.

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Water Temp (c) --- D.O (mg/L) 

 

       0                           14.6  Good

       5                           12.7       

     10                           11.2       

     15                           10.0  perfect

     20                             9.1  

     25                             8.2    

     27                             7.9  fatal             

     30                             7.5  

 

This chart does not factor in the fish loads, how clean the system is or plants that are present which can all change the dissolved oxygen level.

 

Signs of low oxygen levels.

Sturgeon either roll over onto their back due to losing balance.

Or they spin in circles, in the same direction. Both are a lack of oxygen to the brain and it is causing equilibrium issues. 

Place them in cool aerated water and gently rock them back and forth with enough force so the gill plates open and close. This should flush fresh oxygen into their system.

The cooler the water the more oxygen there is to help them.

Also the time it takes water temperature to change can shock fish. Sturgeon cannot handle temperature changes of more than 4c (Deg) per hour.

So shallow ponds are not great at slowing down temperature fluctuations. A depth of at least 1m, and shade helps combat this. Trapped air, air bubbles trapped in the body is a problem for sturgeon. They are unable to dive and feed, which in turn is even more problematic for them.

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Sturgeon Behavior

 

Although some Sturgeon species are known for being a large predator at the top of the freshwater food chain.

Most Sturgeon are placid fish that can live alongside other species of pond fish including koi, goldfish, orfe and tench, with no  problems at all.

However they are carnivores and if they taste what they decide is food, it will be food.

They huddle and have done since they hatched

This is called "swarming" when they are hatch lings. They can be only days old before 10000s of them will swim around as one to look like a larger fish, it's not a shoal full of scared fish.. it's something very different and fascinating to watch.

It's like 10000s of sturgeon fry pretending to be a full grown sized fish and hugging the bottom searching for food.

They can "tail walk", like dolphins do.

Swimming upright with half their bodies out of the water. I've heard plenty of reasons they do it..but mostly it's trying to get your attention or watching you.

Feed them, they'll do it if they are hungry.

 

Sturgeon Health Issues. 

 

Sturgeon are Vectors meaning they are immune to most disease and viruses but can carry them unaffected. They will not suffer from anything really other than bacterial infections.

This is not something sturgeon suffer from, it is a result of poor pond maintenance and cleanliness.

 

Parasites on Sturgeon

 

Sturgeon are rarely bothered by parasites in the garden pond. 

Sturgeon in the wild migrate from the ocean/coastal estuaries, travelling inland to spawning grounds in freshwater rivers & lakes. Sturgeon are anadromous meaning they can live in either fresh or salt water and switch between the two. 

 

Maybe sturgeon are clever, maybe this is just coincidence.

If they are subject to parasitic attacks on their outer body from marine dwelling parasites. They travel to water that kills all the parasites in freshwater. They can do this anytime they like, and change the environment they live in. Not many fish can do this.

 

Around 2010 there was a study on Lake Sturgeon, almost by accident they found something remarkable. Lake Sturgeon showed they can take some genes from parasites. They can take genes from parasites. More research is needed but could this be some type of evolutionary defense against them. Maybe this is wild out of the box thinking but what if they are taking on the parasites genes so to a parasite, they are just another parasite and not a host.  

 

I also have this theory too..

When a sturgeon is killed for caviar it is knocked out and drained of its blood while it's still alive, the reason is because if a sturgeon is killed instantly it releases a toxin, tainting the meat or caviar (roe), so this could be the reason that they simply just don't taste good to a parasite while they are alive.

Also fish smell fishy, but if you actually smell sturgeon, they smell like citrus.. so maybe they taste too citrus, because if you have tasted quality caviar you get an aftertaste of grapefruit, could be that too.

 

Once in fresh/brackish water they are only bothered by internal parasites/pathogens which may affect their digestive system or swim bladder, they will swim to the coastal areas, and rid them via salted water. 

The freshwater parasites that attack the outside of the body that commonly kill carp/koi. Rarely bother sturgeon, if at all.

Maybe this migration will help cleansing of external parasites ready for spawning. 

Sturgeon will also remain unaffected due to the thick like leather skin compared with soft koi skin. Freshwater parasites just don't thrive on sturgeon like they do on koi.

 

As for parasites living on Sturgeon you'll see plenty of papers, most are dated in the 1800s or 1930s quite old so are then rewritten. So if you read these, you can say there are parasites on Sturgeon. You will then find in the mix a couple that say these tests or papers are inconclusive for a Sturgeon to be a host. This is because they may have just been passing through a said area and had stragglers, just on the Sturgeon but not living on the Sturgeon. 

So scientifically out in the wild you have to assume they have them although there are conflicting papers. There is no paper that puts parasites on a sturgeon and  the life cycle of the parasite to prove they feed and breed on a sturgeon host to date. 

But for arguments sake, let's say there are parasites attacking Sturgeon like they do koi, there are 1000s if not millions of pictures of koi with damage caused by parasites of various types...how many Sturgeon pictures do you think there are with parasite caused damage....from the invention of the camera...not one picture. zero. 

Online sites show you parasites and "buy this" to rid your sturgeon of parasites, but all are pictures of fish with scales, not one is a sturgeon.

They must have forgotten to take some pictures or a video to actually show the damage parasites cause on Sturgeon.

 

Another reason why it is thought they may become caught on the Sturgeon like free floating algae rather than living on them.

Is the point of what type it was and so look at the parasite itself..is it freshwater or a marine species that was found on the Sturgeon. Meaning the freshwater body parasite would not survive on a host that traveled into sea water with a salinity level able to instantly kill the parasites. Think about it, if all freshwater parasites like  or freshwater body fluke all targeted a host that is immune to virus and disease and lives for 100s of years and the sheer size some Sturgeon reach, Sturgeon would be a far better host than the carp. 

But...that could mean a Sturgeon could literally wipe out all the freshwater parasite species in one single day. All it would have to do is travel along its migratory paths while using its anadromous nature to swim from a freshwater waterway to the ocean. That is it, that's all it would take for all the freshwater parasites to be dead in one go. It doesn't make sense for them to choose such a fish as a host that can do this.

 

Parasites need a host to thrive on, it doesn't know its in a pond filled with tap water on some estate in middle of Yorkshire or travelling down the river Volga in Europe, surely it's too risky to choose to live on the anadromous fish as it may be travelling down the Volga or Thames towards the sea where the parasites will soon instantly meet their doom.

They would not seek a host that can live in salt water like a carp that doesn't dwell in the sea, if they are freshwater\brackish parasites they want a freshwater\brackish based host.

Sturgeon are not a good parasitic host. 

 

Also i mentioned a while back that Sturgeon have to be killed for the egg roe, this is because if they die suddenly they release a toxin, it's called Ciguatoxin. This is to protect against predators eating them or their soon to be released eggs.

This is why Sturgeon are knocked out first and drained of blood before eggs for caviar are taken. So if you are a parasite, and you kill the sturgeon it will probably kill all of the parasites as well.

There are 100s of fish that do this, mainly reef fish and parasites probably know and parasites probably avoid these fish types the most.

When you have sturgeon imported, they are not like koi,  30% of the batch are subjected to being slaughtered and tested for everything inside and out and if they are found to be carriers of anything the import is not allowed and wont go ahead. If they have come into the UK legally they will be, everything free. 

The reason is because they are Vectors they can carry nearly any virus, disease and remain absolutely in-effected.

 

So with my opinion and theory of why parasites wouldn't choose a sturgeon host or leave asap if they were to find themselves on one, I'll finish it with this.

So here is a little on the stragglers too.

I have scraped quite a few, in fact 1000s and found no parasites, over years and years I've had many calls about this very thing, "if i treated the koi will the sturgeon bring back in the parasites"...did you scrape the sturgeon, "yes but no parasites".

Those sentences have been quoted to me 1000s of times. 

I trust if they find them on the koi they would also be on the Sturgeon, but in all cases not one person came back and said yes it has parasites, not one.

I am 99% sure they won't carry them or be a hive waiting to be placed back in the pond, because we as a community of Sturgeon keepers would have found one. 

 

You should look to protect your fish pond from birds and insects like snails or new additions whether its fish, plants or equipment. This is where most parasites come from.

 

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 Treatments for Sturgeon and Sterlets.

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You should take precautions especially when using PP, formalin or any with high metal content or with oxygen stripping properties.

Some products for fish that can affect the digestive tract of parasites that could harm Sturgeon such as fluke treatment, harm them on the inside and as treatment ends and weeks pass your sturgeon could suddenly become ill which is then fatal, but looks like it's for no reason. 

 

Algae treatments, pretty much all of them labelled as safe, some have no labels deemed as safe. Are they safe, how can you know if you don't know what is in it?

Can they calculate how much of the dissolved oxygen will diminish while using these algae medications, probably not.

Some use metals like zinc, a mineral. Very toxic to fish in high quantities. But described as "natural minerals" again this could be just marketing.

Monolinuron is another very common but the label states the product as safe.

So just check if unsure with a quick online search of the ingredients..I promise you, you will be shocked what these people have you bath your beloved pets in. 

Yet we really can't blame the med though, it's not the med that are the problem.

It's the lack of understanding what the med are going to do or change that is the problem. I mean you wouldn't pour soap into a pond because you understand what will generally happen, it's common sense it'll be bad for the fish. So just a quick search of the main ingredients in these products will help you decide whether you wish to use them or not.

 

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Quarantine Sturgeon

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Take Sturgeon out and place it in QT/hospital tanks while treatments take place if possible..every pond should have some sort of QT/hospital tank. A small blow up paddling pool will do if you're stuck for space. 

 

Bacterial infections can kill Sturgeon or  Sterlet. Acriflavine helps for example, but at the risk of the fish becoming sterile according to some papers I have read.

And the list goes on, one tiny benefit for a host of terminal ailments.

On this bacterial infection though, the fins can be red and drop to one side, if the fish looks limp and tired you should check him and give cool fresh water, salted if you can.

 

Trapped air or enlarged swim bladder issues.

This can be fatal for obvious reasons like the sturgeon can not dive and feed which in time proves fatal. Stress, could you imagine just one day waking up and you are a balloon floating around your house.. hilarious until you realize you can't stop it.

The causes can be a number of things, but mainly gulping air looking for food on the surface because they are hungry, spending time around air stones as mentioned before and taking in a few air bubbles or being held over air stones because the owner thinks it's helping.

This trapped air can sometimes be massaged out.

Be gentle and use a firm single motion from the vent towards the head. Vent towards head.

Pressing the air out, this will pop out and best to do underwater so you can see the air come out and they don't take any more in. Be firm but gentle because all the sturgeon organs are in the middle.

Only do this for a Few minutes, then leave so not to cause more stress. Try again if needed in a few hours.

 

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Which treatments are safe for sturgeon

 

We always say NONE. This is because it's not a 100% guarantee they are safe.

They generally don't need them. Also, I've said it is pure luck whether your Sturgeon will survive a treatment, that is quoted from a well known manufacturer.

If any creature was starved of oxygen for long periods of time, it would be a miracle if they survived, but surely they have sustained brain damage. Some keepers of Sturgeon still seem to risk this with Sturgeon. Take them out and Qt them.

Malachite green for example stays in the fish for a very long time. Malachite is a mutagenic, it causes cancer in fish and humans. Yet doesn't state this on the label and koi keepers continue to pour "mg" into their water. 

Don't take my word for it..look up what's in the bottle, it's all there in black & white.

Some won't even tell you what's in it..could be cyanide for all we know, but "natural minerals" is in the description..cyanide is a natural chemical. So if you don't know, it's not safe.

I think more clarity should be put on the bottles for the average user with regards to Sturgeon and the possible side effects. But like most things if you focused on the side effects etc, you'd probably not use them. 

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I'm Not saying all manufacturers are unhelpful because most will definitely take calls from customers if they have problems with products or even just queries..some not all. So if you're left with injured Sturgeon after following the instructions to the letter and disaster has happened while using a said pond treatment, be sure to call them and let them know.

They cannot help if they do not know. They can tweak the amount which in turn may not harm the Sturgeon. It may take a few more doses but the fish and Sturgeon are all healthy and unharmed in the end.

All that said, the main point here is to take out your Sturgeon when treating other fish or the pond, but if you don't take them out and treatment is fatal, just let the manufacturer know. 

 

Salt and Sturgeon

 

Sturgeon are anadromous fish meaning they can live in either fresh or saltwater.

Sterlets are considered only to dwell in freshwater in the wild.

For that reason let's say Sterlet are primarily freshwater fish.

So a salt bath with a lower Salt content would be better for Sterlets.

 

Salt baths

2 oz or 55 grams of salt per gallon of water for Sturgeon, for  20 mins

Stay with them, use a salt meter.

Pond dosage of one 25kg sack for 2000 gal pond 

gives the rough amount you would need for a dose of 0.3% salinity. Have a salt meter to hand.

Many people salt their ponds, some short term, some long term. 

The benefits far outweigh the negatives.. in fact i can't think of any negatives. If you know what you are doing and

trying to achieve. 

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The Garden Pond and Sturgeon

 

Sturgeon can also have other issues too.

Plants in the pond such as long grasses, Lilly and reed type plants can be an issue for very small Sturgeon and Sterlets because they cannot swim backwards and can become trapped. With the five rows of scutes running along the full length of their body, blanket weed/string algae can be deadly for small sturgeon if it grows out of control, snagging them. Heron nets or safety nets can pose a similar problem of snagging Sturgeon if left hanging on the water's surface so be aware of this too.

A heavily planted pond can be troublesome for Sturgeon during hot summer nights where the plants stop producing oxygen and produce carbon dioxide instead, the content of oxygen in the water can become very low due to the high temperature.

 

Also low pressure, i.e. thunderstorms again creates low oxygen levels in ponds. 

 

Sturgeon need at least 8-11 mg/L content of dissolved oxygen

Koi live happily with a oxygen content of 6 mg/L

In hot weather you must have aeration in the pond.

Say you have 2000 gal pounds, a 60L-100L air pump would be fine, that's money well spent. 

Your pond, filter and fish will seriously benefit. 

But if on days where the weather is so hot the dissolved oxygen still seems to be going down to dangerous levels that may harm your sturgeon. You must be able to cool the water somehow. Coiled DIY hose pipe in the freezer while running through a dechlorinator cartridge would suffice in emergency situations.

 

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So to remind ourselves

 

Feed Sturgeon and Sterlet daily or mainly at night, the right type and size of high protein sinking food.

 

Plenty of fresh clean aerated water and try to it keep cool in hot weather.

 

Keep more than one Sturgeon or Sterlet.

 

Advice, question it before acting.

 

Be careful if treating the pond or other fish with chemicals and check the label.

Remove Sturgeon from the pond and place in the qt/hospital tank while treatments are used if possible. Let manufacturers or dealers know if problems arise.

 

I haven't covered all aspects of Sturgeon keeping. I hope this basic guide has helped you understand a little more about Sturgeon & Sterlet and how to keep them safe, happy and well. 

Disclaimer, this is just my humble opinion from my experience keeping sturgeon.

If your fish is ill or you need assistance, you should contact your local stockist or fis vet to help as they should be able to give the best advice to you in time of need. 

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written by

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Mark Addey

Sturgeon Guy

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