Sturgeon care guide

Sturgeon and Sterlet Keeping Guide

No two ponds are the same and water parameters will fluctuate. Fish stock numbers, feeding rates and filtration systems all factor in these changes.
So read this and treat as a guide only.
What works for someone may not work for someone else.

 


✴Parameters:


PH: 6.0 – 8.5

Total hardness 50-400ppm

Oxygen 8mg/L
(minimum in summer)

Ammonia (NH3) 0.01 mg/L

Nitrite (No2) 0.01 mg/L

Nitrate (No3) 100 mg/L

Temperature 2c – 22c



✴Pond size:


Sterlets 1000gal/min
Sturgeon 2000gal/min
But this is not essential until fully grown
Depth at least 3ft/1m



✴Sizes & Lifespan


Sterlets: 0.6m-1m approx. 20yrs+
Albino Sterlet
White tip Sterlet


Sturgeon: 1.5m-2m approx. 50yrs+
Siberian
Diamond back (Russian)
Stellatus
Ship


Huso: 5-7m+ approx. 100yrs+
Kaluga
Beluga


Hybrids are normally bred with Sterlet, so sizes and ages are thought to be like the Sterlet approx. 1-1.5m, approx. 20-30yrs.



✴Handling Sturgeon


With smaller Sterlet you can a net quite easily, just make sure the scutes are don’t get tangled up & damaged. 


Sturgeon spines are not much stronger than a hotdog & break easily if dropped or fall a few feet from a net.


Handle large sturgeon with your hands, bring the head close with net. Hold the head first, this is essential because if you hold the tail first you set off its fight or flight reaction & they tend the choose flight. 


Cup the Sturgeons head in your hand so the gill plate is in your palm with mouth facing you, thumb will fit in the mouth ridge. Then hold the tail and lift in one motion. Use a wet towel for grip. 


Lift tail high with head around your hip area. Hold firmly but be gentle, it will form a "J" shape. If it twists, raise hand with tail and loosen grip on head, keep the head near your hip. Cup head again and carry like this to pond/tank. 



✴Feeding


Sturgeon are bottom feeders that eat meat.


Sturgeon DO NOT eat algae or clean the bottom of the pond.

Feed Sturgeon twice every day a minimum of approx. 0.3 - 1.0% of their body weight depending on age and size. You can go to 4% of body weight but it’s not needed. 


We suggest specially made Sturgeon food above 45% protein content. Sturgeon fed with 42% protein in our opinion do not grow as well. Its standard food and malnutrition being the main killer of young sturgeon you should not scrimp on the protein content to save a few quid. Do not use trout/halibut pellets. 3-5% protein content difference in one pellet is a vast amount. 


We recommend feeding little and often just after dark due to them being dusk till dawn feeders and more active at night. 


Lack of food is the main issue for sturgeon stress and fatalities. 


Feed daily, there is good reason for this. Without food in the belly the stomach carries on producing more acid and build up until it ruptures the stomach lining. When this happens, the acids will leak out onto other organs and start to dissolve them. This is fatal. 


When Sturgeon struggle to feed some use the method of food down a pipe. This method is not great, but whatever helps right. 


Koi for example soon become wise to this pipe method. 


Scatter the food at similar places & similar times late evening, the sturgeon will be more active and find some. Avoid drains and air stones when throwing food in the pond. Compensate for the other fish that will eat the food too.


You'll see on some things I repeat myself. Yes, it is that important. 

"The koi are eating all the food"
Koi are omnivorous, koi are true bottom feeders. 


They are very happy eating sturgeon food so just put more in for the fish that missed out. Take out any uneaten food with net. 


You wouldn’t let your dog/cat starve because dog/cat No. 2 ate all its food, no you would feed them some more. Same with the fish. 

Feeding one sturgeon or Sterlet amongst 10-15 koi is always going to be a problem.


Just like if it was reversed, 1 koi competing with 10 sturgeon. Even the odds out a little, have a few in the pond, they communicate, and you’ll see a difference in the once lonely single sturgeon. 



✴Signs of malnutrition in sturgeon:


Early signs are body shape, you want the sturgeon to be the same width as its head all the way down to its dorsal fin. 


Starting to bend into a horseshoe shape. This is too late, sadly the Sturgeon/Sterlet will die. Takes on a horseshoe shape. 


Although swimming upside down on the surface is a regular sight in juvenile sturgeon as they are always hungry.


To see this behaviour above a size of 12 inch the sturgeon is at least very hungry, up its daily intake of food. Little but often is better.
Digesting food every 30mins - 1hr. But twice daily is enough. 


Sucking the mucus off another fish, sucking the sides of the pond wall or poking nose out of surface also indicates the sturgeon is hungry.



✴Food/pellet size & approx. sturgeon size:


2-3mm for 6-14″
3-6mm for 14-20″
6mm+ for 20-25″ and so on.


This is a basic guide due to the different types and mouth sizes Sturgeon and Sterlets have. Stellate Sturgeon and Sterlet have very small mouths. 


You can roughly measure their closed mouth. Half the size of their mouth gives you the size pellet they will be happy with.


So a 10mm wide mouth they want approx. 4-5mm pellet.


Every fish is different so treat as a rough guide.


Sturgeon will sift through debris in your pond trying to find insects or missed food. 


They do not to eat the dead leaves and plant debris. They cannot digest most plant proteins so cereal or soya-based foods are no good for sturgeon, check label.



✴Aeration.


Koi can happily swim in a pond a with 6mg/L of dissolved oxygen (D.O) content. 


This level would almost surely kill a Sturgeon. Many koi medications will strip oxygen to this low level and will cause the Sturgeon problems. 


8mg/L is the minimum they require, Period.


Water and oxygen mixture happens where they both meet. The smaller the air bubbles the faster they will mix. Most air stone are useful because although not a great deal is mixed as the bubbles rise, they pop on the surface and there is plenty of water/oxygen mixture going on. 


Sturgeon food is oily, it can create a film over the surface of a still pond. Air stones will break the film and help mix the air with the water.


There are different types of air pumps and air stones out there, ponds generally use 8mm pipe or airline with a 60L-100L per minute pump. This would be fine with a couple of 10" discs or cylinder stones (debris can’t get trapped under the cylinder stone) in a 2000gal pond for example. But more mixture the better so maybe two pumps, one for filter one for the pond. 


Don’t forget your non-return valves for the airline so the pumps don’t syphon water into the pump if you have a power outage. 


Do not place your sturgeon over an air stone.


Trapped air, air bubbles trapped in body cavity is a killer of Sturgeon. They are unable to dive and feed, they can get sunburn and are easy pickings for predators if floating around on the surface. 


Do not place sturgeon over air stones. 


Here is a small chart of the water temperature dissolved oxygen content 


Water Temp (c) - D.O (mg/L) 

 0 - 14.6
5 - 12.7
10 - 11.2
15 - 10.0 *perfect*
20 - 9.1 *optimal growth*
25 - 8.2 *getting low*
27 - 7.9 *sturgeon issues*
30 - 7.5 *sturgeon killer*


Bear in mind on this chart, you see you have a set amount of D.O in the water in your pond at a certain temperature. Don’t forget other factors like fish, plants (at night) including algae and the bacteria in the pond and filter. They all take oxygen from that amount. So, if you have 10 fish in the pond and its 25c at 8.2mg/L of D.O, there is probably less D.O than 8mg/L.


Aeration is key and in summer with hot temperatures either cool the water going in just to add more oxygen as colder water holds more.


 Hose pipe coiled in large bucket of ice for example or a separate QT tank that can be kept cool and shaded would be a great idea.



✴Living with other fish:


Sturgeon are friendly placid fish that can live alongside other species of pond fish including koi, goldfish, orfe and tench etc. With no issues or problems at all.


Be aware of the larger fish at 4-5ft plus swallowing the odd fingerling, they cannot see what they taste. All fish will pick at the weak and finish them off. With Sturgeon, it’s just swallowed whole.


We normally see ponds with 10 fish and only 1 sturgeon for example and we always wondered why. Most people we have asked mentioned the size sturgeon can reach, a very valid point, you must build a suitable size pond, while calculating your pond build also plan for a few sturgeon as most ponds 8 out of 10 ponds will end up with a sturgeon or two in them. 


We say plan for at least two.
They are pod fish meaning they are social, sleep/rest together, feed together, swim together and new studies have shown they will communicate with one another with a deep rumbling sound. Sturgeon are a lot more at ease with a few other sturgeon or Sterlets about. 



✴Sturgeon health issues. 


If kept within good quality and well aerated water, sturgeon will put many other fish to shame, health wise. 


Sturgeon are Vectors meaning they are immune to disease and viruses, but they can carry them, pass them on but remain unaffected. Properly quarantined sturgeon will be free of disease or virus but check if your dealer/seller has properly quarantined their other fish stocks too, if they sell other species namely carp/koi. 



Parasites 


Koi suffer bad for these nasties.
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 salted or freshwater, or switch between the two. 


Maybe sturgeon are clever, maybe this is just coincidence.


They are subject to parasitic attacks on their outer body from marine dwelling parasites, when ready to spawn which is a critical part in their lives. They travel to water that kills all the parasites i.e. freshwater. 


Once in fresh/brackish water they are only bothered by internal parasites/pathogens which may affect their digestive system or swim bladder, but as far as studies have shown fatality counts are very low. 


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


My opinion is that this is intentional along with other factors, and this migration is for the cleansing of external parasites ready for spawning. 


Sturgeon will 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. 


Unfortunately, most chemical treatments for ponds or parasites have not been tested on Sturgeon. Many firms claim they are safe, but this type of testing is illegal on sturgeon within the UK. So how do they know. They don’t. 


There has been no testing on sturgeon in the UK, this is illegal because they are an endangered species. You can query the manufacturers themselves, they say its pure luck whether treatment goes good or bad.
Some treatments are worded with
“safe for sturgeon”
This is so wrong because it seems they plaster sturgeon on the label because they know nearly all ponds have sturgeon in. 


So be very careful of the advice you take and the toxins you're advised to pour into your pond. 


Some cure, some kill. 


You should beware and take precautions when especially using PP, formalin or any with high metal content. 


Some products for fish that affect the digestive tract of parasites that could harm Sturgeon such as fluke treatment. 


Many use PP and strip the oxygen from the water, but many don’t put the oxygen back in the water, this is very bad for Sturgeon and usually ends in death.


Algae treatments can also be harmful to Sturgeon and sometimes be fatal due to the process stripping the water of oxygen, again causing lack of oxygen issues for sturgeon. 


Take Sturgeon out and place 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. 


I’ve been asked these questions 1000s of times:

✴"will the sturgeon have parasites too" 


I have yet to see in 20-25yrs proof of a parasitic infestation on a sturgeon. Not one. 


Maybe a couple are on a sturgeon. But being on the sturgeon purposely to feed n breed...Nope


✴"Which treatments are safe for sturgeon"


We always say none, as I’ve said it is purely luck whether your sturgeon will survive treatments, this is what I’ve been told by manufacturers. 


One or two maybe safe but this is not for certain, they could be affected on the inside from these chemicals. Malachite green stays in fish for life and is a mutagenic, it causes cancer in fish. 


I think more clarity should be put on the bottles for the average user with regards to Sturgeon and the side effects. 


Manufacturers will take calls from customers if they have problems with products. So, if your left with dead sturgeon after following the instructions to the letter and disaster has happened. Be sure to call them, they cannot help if they do not know. 


Take Sturgeon and Sterlets out while treating the pond and salt bath the sturgeon if you feel the need.


Sturgeon are anadromous fish meaning they spend parts of their lives in the wild in both
sea water and fresh water. They live in seawater and spawn in freshwater. So, a salt bath would be good for them occasionally.


Sterlet are considered only to dwell in freshwater in the wild.
So let’s say Sterlets are primarily freshwater fish.
So a salt bath is fine, but a lower Salt content would be better for Sterlets.



Salt baths


2oz or 56grams of salt per gallon of water for Sturgeon, for approx. 20mins.


Pond dosage. 


25kg for 2000gal pond
approx. amount you would need for a dose of 0.3% salinity


Many salt their ponds, the benefits far outweigh the negatives.
But it’s a Sturgeon guide not a salting pond guide. 



✴The garden pond and Sturgeon:


Plants in the pond such as long grasses, lily 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 can be very dangerous 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 beware of this too.


A heavily planted pond can be trouble for Sturgeon for this reason, 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. Low pressure, i.e. thunderstorms again creates low oxygen levels in ponds. 


Sturgeon need at least 8-11mg/L content of dissolved oxygen
Koi live happily with an oxygen content of 6mg/L


In hot weather you must have aeration in the pond, no ifs, no buts, and none of the cheaper fish tank air pumps, you have a pond spend the money and buy a proper pond air pump. 


Say you have 2000gal pond, a 60L-100L air pump would be fine, that’s £50-100 well spent. 


Just go get one and plug it in, your pond and fish will benefit greatly. 


So, to remind ourselves,


✴Feed Sturgeon and Sterlets daily the right type of high protein sinking food.


✴Plenty of clean aeration/oxygenated water


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


If you’re still unsure, remove Sturgeon from pond and place in quarantine/hospital tank while treatments are used.


I hope this basic guide has helped you understand a little more about Sturgeon & Sterlets and how to keep them safe and happy. 


MARK ADDEY
KC Caviar