Sterlet Sick? Acipenserids; not for aquarium use  6/30/09
Hell Wet Webbers...My name is Peter Sewchok. You have helped me with several questions through the years.
I just purchased a very young, very small Sterlet (cousin of the larger Sturgeons for those reading). It is roughly an inch long, and I have it in a 40 gallon breeder
with mini-Amazon sword plants, some Cabomba, and a fine sand bottom. The Sterlet has started swimming like he is crazy; loops, upside down, etc. I know that they swim in odd patterns, but the past two days I found him lying on his back in the sand bed.
<I see... is he resting, or are his gill covers moving rapidly, as if he's panting?>
I have two large Bio-wheels in the tank and a powerhead for a current. The nitrites are zeroed, and the nitrates range from very small to zero before water changes. I hope that he is not near death. I am feeding high-protein flake food as he seemed to ignore the black worms and carnivore pellets.
<I'd be offering a more varied diet, in particularly with wet-frozen wormy things: bloodworms, Tubifex, etc.>
Water is cool.
<By which, do you mean the aquarium is unheated, or that there's a chiller attached? Optimal water temperature is about 14 degrees C; anything above 18 C is essentially lethal. Like a lot of Eurasian fish (such as Koi and Goldfish) they prefer water that is hard and alkaline, so avoid soft, acidic conditions. Kept cool and in the right water, this fish is actually quite hardy, though like a lot of "primitive" fish it is quite possibly intolerant of copper- and formalin-based medications.>
Any help? I know Sterlets get huuuge...his retirement home is a large pound. I lost two other larger Sterlets in a different tank; one leapt out despite it's hood, the other managed to mangle itself fatally on a powerhead. Please send any advice that you can: I love Sturgeons, sharks, and rays. To me, the Sterlet is much like a TRUE freshwater shark; basically the closet we will probably ever see in the hobby.
<More specifically, Sturgeons retain some primitive characteristics that sharks also possess, such as the heterocercal tail. Oddly enough, of all the living fishes, they're most closely related to Bichirs, though the two groups diverged sometime during the Triassic Period.>
I just also wanted to post a final note: Despite what one might read on the Net, Sterlets / Sturgeons are very tricky fish to keep...up there with salt Catsharks and freshwater rays.
<Like a lot of European fish, they're "tricky" when kept too warm; unlike the Continental United States, which experiences long, hot summers even in the northern temperate zone, Europe has a more maritime climate and summers are rarely particularly hot. So European fish tend to be adapted to relatively cool water, and compared with North American fish like Darters and Sunfish, they're often less tolerant of indoor temperatures. There are plenty of exceptions of course, but Sturgeons aren't among them. It's absolutely critical they're kept cool and provided with water that has a massive rate of turnover and lots of oxygen. I'd be aiming for a turnover rated 8-10 times the volume of the tank (i.e., a 320-400 gallons per hour filter for a 40 gallon tank) and using a venturi jet return to keep the water well agitated.>
Think before you try them.
<Weirdly, they're not infrequently sold here in England as pond fish; they can do well in big, deep, well-filtered ponds, but you don't see them much!>
Despite years in the hobby (15+), I am starting to believe that Sterlets are best left in the river.
<Certainly true for the larger species; Sterlets and the "Bester" (a Sterlet/Beluga hybrid) are farmed, so the ones you see in pet shops are most likely hatchlings from fish farms. As such, they're worth experimenting with if you're an advanced hobbyist interested in big, coldwater species.>
Thanks all,
Peter
<Cheers, Neale.>

Re: Sterlet Sick? – 07/01/09
Thanks for the response. The Sterlets that I have worked with before seemed to filter feed some of the time like their cousins the Paddlefish, and they largely ignored frozen foods.
<Sturgeons aren't filter feeders, they're predators, feeding primarily on insect larvae and crustaceans when small, and small fish when mature. They certainly don't need feeder fish in captivity, and as you probably know there are multiple compelling reasons not to use feeder fish anyway. But they certainly should receive a varied diet of meaty foods: earthworms, small crayfish, snails, mussels, prawns, etc. Once settled, they usually take carnivore pellets, but they're not "scavengers" as such.>
This guy is responding to some freeze dried bloodworms that I bought today (Omega 1), and still really seems to like the protein flakes.
<Dried foods are insanely overpriced for what they are, and many fish reject them. They can also cause constipation if used continually. So get yourself some wet-frozen foods: bloodworms, krill, mysis, Tubifex, etc. and use these as the staples, along with a bag of mixed frozen food from the supermarket (here in England at least, typically mussels, squid, and prawns).>
I don't think he likes the blackworms, which is strange because delicate fish ( ie stingrays) seem to love them.
<None of my fish like freeze-dried anything. Never have, in 25+ years of keeping fish!>
The weird swimming is still going on occasionally, and I'm wondering if maybe this is just the way some small sturgeon swim. The water turnover should be fine - Two Marine Land 800's and a sand level powerhead. I find it odd that Sterlets are used in ponds in Europe...wouldn't a pond with driftwood and plants present a softwater situation like one might find in a bog or in the Amazon?
<Not really, depends on the water chemistry, circulation, etc.>
To answer your question about the temp in the tank: no heater, no chiller.
Chillers are really hard to come by here in Pittsburgh, PA.
<Try mail order; widely used by marine aquarists.>
The room is cool - air temp 67. That's basically year round.
<That's your problem. Too warm. An old "mini bar" fridge, with a couple holes drilled in the case, and a couple metres of outlet pipes from a robust external canister filter does the job well.>
I don't have a thermometer in this particular tank. Lighting is minimal.
Tankmates are a half-inch long mad tom catfish that I rescued from the feeder tank of a local
FS, and a Hillstream loach / china loach / china Pleco (erro). I'm going to add an air stone for extra O. I also wanted to ask about these new filters that use a chemical process to remove Nitrate Matter...are they the real deal?
<Don't do anything water changes won't do, and certainly don't remove the need for regular water changes. Cheers, Neale.>

STERLET SICK UPDATE  7/3/09
Hi again. I made a "cheap chiller" by running a tube from the freezer of a small fridge from college. It's a little cooler in there now. Sterlet is still a loopy little thing. He ignores frozen bloodworms, is eating frozen brine from Oregon Foods, and the freeze-dried bloodworms. No idea why...maybe they smell salty?
<Maybe. In any case, just keep varying the foods. Freeze-dried bloodworms (indeed, freeze-dried invertebrates generally) aren't an acceptable long-term food. They're too expensive and too prone to causing constipation, which in turn increases the risks of bacterial infections. So be creative; I'd recommend wet-frozen krill as being especially nutritious, and these should be taken readily enough by Sturgeons, as should wet-frozen Mysis and chopped cockle.>
He isn't lying on his back anymore or swimming upside down as much. I think he might be eating those annoying little black pond snails, too...there some empty shells in there now...unless they are eating each other.
<Yes, they eat snails.>
I would think that the tiny bullhead type catfish that lives in the tank would probably eat them whole rather than shelling them, but I don't know.
Can you recommend some other coldwater companions?
<Most anything non-aggressive that enjoys the same cold conditions; Sturgeons are predatory of course, so small minnows and such will likely be eaten, but otherwise things like Carp, Tench and so on work well. Avoid territorial fish like Sunfish, since the constantly active Sturgeon will repeatedly invade their territories, leading to conflicts.>
Benghana Bengri maybe?
<I have no idea what these are, and more surprisingly perhaps, nor does Google!>
I was also wondering if you guys could help me find info about freshwater pipe fish. I have found them available, but have no idea how to set up a tank for them. I would guess it would be similar to a seahorse tank, but I don't want to guess.
<Yes, they're very like *wild* as opposed to tank-bred Seahorses. They are notoriously difficult to feed, and generally take only live foods, primarily Daphnia in the case of the midwater Pipefish (such as Microphis and Syngnathus spp.) and Daphnia plus insect larvae such as bloodworms in the case of the species that like to crawl about on the bottom as well (as in the case of Enneacampus spp.). The bigger species will take very small livebearer fry as well, such as newborn Guppy fry. So it's not worth keeping them unless you have access to a constant supply of live foods, such as garden pond. Now, another key problem with Pipefish is that retailers generally do not know what species they are selling. Unless you have a Latin name, be critical of anyone telling you it's a "freshwater pipefish"; the reality is that many so-called freshwater species in the trade are brackish water species, and will need at-least slightly brackish (SG 1.003-1.005 at 25 C) conditions to do well. Do see here:
http://www.wetwebmedia.com/brackishsubwebindex/fwbracpipeshorsart.htm
Cheers, Neale.>

Re: Sterlet Sick? - 07/03/09
Hi yet again...Thank you so much for all of your help with my Sterlet. He thanks you, too. The fish that I mentioned in my previous mail that you couldn't find on Google is actually called Bangana behri. I spelled it incorrectly last time.
<I see.>
It's a large, strange carp. From what I am reading, probably too large.
<If in doubt, Fishbase!
http://www.fishbase.org/summary/speciessummary.php?id=16212Yes, at 60 cm, this would be of questionable value as an aquarium fish, let alone a companion for a *coldwater* fish like a Sturgeon. Though best kept alone, in a sufficiently large aquarium, coldwater carp-type fish around 20-30 cm in length would make good companions. Hardy Goldfish, young Koi, Tench and so on are all obvious choices.>
I bought some Mysis today, and some krill. We'll try those. Thanks again.
--Peter
<Good luck, Neale.>

Re: Sterlet Sick?  7/5/09
Hi crew. Just wanted to thank you, Neale. Sterlet seems much healthier / happier. Swimming laps around tank like a "normal" fish, playing in jetstream bubbles, resting in sand much of the day. No more "panting"'
gills moving normally.
--thanks again,
Peter
<Ah, this is good news! Glad to hear the chiller has made a difference; usually does, and especially so in summer. Happy fishkeeping, Neale.>