Polypterus Senegalus in 40 Breeder?

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Lillyan

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Can I keep one or more Polypterus Senegalus in a 40 gallon breeder?
How many can I have and what tank mates, edible and just mates?
Anything else I should know?
 

GoldLenny

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Temporary home while the fish are fry/juvis or permanent home?

Mongabay http://fish.mongabay.com/species/Polypterus_senegalus.html shows these fish grow to 16" and another reputable site, Badmans, shows them growing to 20".

Those profiles/care sheets suggest a minimum of a 45-55G tank or a 48" x 16" foot print for a single fish up to 12"... larger tank suggested as the fish grows.... but remember that a big fish can easily get stunted in an undersized tank if sufficient water changes are not done during their developmental life cycle.

For more than one, the 40G breeder would probably only work while the fish are fry/juvis and maybe up to 6" long... after that, I would move them to a larger tank.

Badman's page has this in their Maintenance section: "... They can be territorial to each other, but if they have their own space this will be minimized...."
 

Lillyan

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Ah, thanks. Guess they are off my list then.

I need another unusual or large fish that can be in a 40 breeder fully grown...
Ideas?
 

RiVerfishgirl

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Heather
Several sites way overexaggerate the size that senegals get to because they're either using max size information from fishbase (and the max size of 20" has NEVER EVER been seen by captive keepers - I'm not sure that recorded size wasn't possibly a mistake. The reference fishbase cites is WAY out of date.), or they're mixing them up with other species.

It is generally accepted that senegal bichirs almost never get over 12", and rarely to about 14", and it takes a very long time for them to grow over 8-10".

A 40g IMO is fine, at least for many years. It's very common to keep them in 55g tanks, and those are shorter front to back.

You can keep several together (given you keep water quality good). Territorial or not, they don't seriously fight with each other. In fact even in a large tank the majority of the time they are laying on top of each other.

As far as tank mates, stick with fish that can not fit in their mouth and are not aggressive.
 

GoldLenny

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Heather/Riverfishgirl,

I know what you are saying but then you have to wonder if the reason they never reach full size in home aquariums is due to stunting because they are being kept in undersized tanks from the start? It's a serious catch-22 situation so I always err on the side of caution and suggest a proper sized tank from the start. Would so-called slow-growing fish really grow slow if kept in a proper sized tank OR are they slow growing because of stunting? I don't know that there is enough evidence in the hobby of people keeping them in a BIG tank from the start to see just how fast they grow.

The same thing was said about goldfish for probably hundreds of years... "They only grow to the tank size or bowl size they are in"... without realizing the folks were seriously stunting their goldfish. If a goldfish is put in a proper sized home from the start, they will grow to 80% of their expected size in the first 1-3 years.. .meaning that common goldfish will be over 12" long in a year and 16" to 18" in a couple of years. I've seen this first hand with my own ponds. Fancy goldfish will also grow a LOT more in a proper sized home but obviously rarely get as large as common goldfish... although there is the exception with Bruce The Oranda who grew to 18" in just a few years. He lived his entire life in a nice BIG pond.
 

RiVerfishgirl

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No, it's not because of stunting. I understand your worry, but if you go over to MFK and read, a ton of people keep them and have for years, including people who are actual experts on Polypterus sp. (beblondie has several articles with info on them there). And there are many people who have kept them for many years with good water quality and they almost never reach over 12" max length, over 14" is pretty much unheard of and if anyone has one over that length I do not know about it and it would be considered a rarity.
As far as slow growth, they are very long lived fish and that is just their growth rate, water quality or not. Once they reach 8-10" they grow very slowly after that. Much like the fact that clown loaches grow to a certain size and then take many many years to reach their max size.

General consensus about the 20" max length referenced is that it's probably a mistake (was not actually a senegalus). The reference cited is from 1984 and that book (Check-list of the freshwater fishes of Africa - volume 1) has a ton of out of date information in it on various fish species. I don't think senegalus have been recorded at 20" in the wild by any recent sources. If you see anyone citing 20" as max length that information is always referenced from the book I mentioned above.
 

rainbowcharmer

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I kept 2 of these in a 55 gallon for 3 or 4 years with no issues. I do not know what they ended up in when I had to quit the hobby for a while - I gave them and the tank away at that time. They were around 9" or so each, and were doing very well. I'd really be OK with them in a 40 gal breeder simply because of the dimensions. Wider rather than taller like the 55 gallon. Honestly I think they'd be OK at least for a few years.
 

msjinkzd

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I actually think they woould do absolutely fine in that tank size for life.
They can be kept with fish that are larger than their mouth. A tight fitting lid is a must. They are not agressive, just opportunistic. They rarely reach over 12". A 40b is a great size because of its width.
 

Just Prince

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Sens only reach a max of 12" Ornates are the commonly sold Bichirs the reach 20" maybe. A 40 breeder is better for a Sen that a 55 because the 55 is only 12" deep where the 40 breeder is 18" deep. You'll get better info from the MFK Poly forum. I have a Sen that's going into a 40 breeder when it big enough. PM Msjinkzd about their care she keeps Polys too. Badman Tropicals is wrong on the size.
 

msjinkzd

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a 55g is also perfectly appropriate for life. Though the polys don't have a huge range of flexibility, they are not a super "active" species. Since sens max out around 12" in captivity, even teh 12" width tanks are perfectly appropriate.

Bigger issue is really making sure that the lid is secure. These are airbreathing species and if they see an opening at the top, they WILL go through it. Please make sure you go above and beyond and securing the lid. I also keep my water line down an inch to accomodate.

As far as tank mates, the senegalus is one that can fit wtih a wide range of critters. Obviously not small tetras, etc but they do well wth fast moving fish in the top 1/3 especially.

They enjoy plants and caves, they are SUPER fun to feed and a very interactive part of a tank. I am excited that you are interested in them. I wish more people thought of polys for their tanks.
 
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