Tank Size for Colombian Shark and Pictus

[000]

Well, here's another newbie that has bought fish that will definitely outgrow his tank. I have a Colombian Shark (Hexanematichthys seemanni) and a Pictus Catfish (Pimelodus pictus). I just bought them from Walmart and they are both somewhere around 2.5" from nose tip to end of tail. I would like to know how long/how big they can get before i need to buy a bigger tank (I'm a student extremely low on cash). I currently have a 14gal (US gallons, about 11.657 UK gallons), 20"x10"x16" (I believe those are the dimensions). Any help is greatly appreciated!

[MatsP]

Columbian sharks need marine conditions (salt in the water) when they get bigger. And they grow to about a foot long, so you need a tank roughly 4ft x 2ft x 2ft - 125 gallon.

Pictus cats should be kept in groups of 5 or more, and need good amount of swimming space, so a 4ft tank, like a standard 55g tank is recommended. And do not tolerate salt in the water, so at some point you need to split your columbian sharks from the pictus cats.

Here's links to the two species datasheets in the Cat-eLog for more info:

Hexanematichthys seemanni

Pimelodus pictus

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Mats

[Viktor Jarikov]

Hi 000, welcome to the club.

In my hands, neither of the fishes was/is a fast grower, relatively speaking, say wrt to Leiariuses, other larger Pimelodids, etc. Maybe they added an inch in several months to 1/2 year. Pictus may grow faster but they remain rather small even at adult sizes of 4-6" TL (3.5-5" SL).

Columbian sharks are definitely one of my favorites too - so-o-o-o-o-o hands-down cute! Just like Cat-eLog says, they can live in fresh, non-acidic water when small - such is my experience too, albeit I always added at least one teaspoon of table salt (non iodized, of course) per 5-10 gal of tank water. If you can add more, (if I am not mistaken up to 3 teaspoons per gallon) that is likely even better. Having been around all LFS's in the 30 mile radius of Rochester, NY and in other states and counties, I have never, ever seen a larger than 3" shark. Never an adult, or even a sub-adult trade-in (trade-ins are the ones I am after in the first place). I'd dearly love to get my hands on one.

Mats: Pictus cats should be kept in groups of 5 or more, and need good amount of swimming space, so a 4ft tank, like a standard 55g tank is recommended.
VJ: Mats and Cat-eLog are right. I've always kept two and they remain a bit shy, rarely displaying elaborate swimming routines. But they have so much character and are humorous in their antics!

Mats: ...And do not tolerate salt in the water, so at some point you need to split your columbian sharks from the pictus cats.
VJ: that's new knowledge to me. Good to know. Mats, if this is true, which I do not doubt, such an important piece of husbandry info MUST (IMHO) be added to Cat-eLog. AFAI could see, it is not there.

Good luck, 000 !

[MatsP]

Regarding salt tolerance in freshwater catfish - if I add that to P. pictus, I should got through about 2400 of the 2533 species we have in the Cat-eLog and add it to them too, because nearly all freshwater catfish [which is nearly all of them] are not tolerant to salt.

I'm not saying "two grains of salt in hundreds of gallons is fatal" - they aren't more sensitive than most other South American freshwater species of catfish. Salt can be used on P. pictus as a medication, but just like we humans aren't supposed to take head-ache pills ALL THE TIME (unless so advised by medical professionals), freshwater fish should not be KEPT in water with added salt, unless the species in particular REQUIRES this.

My point is that they shouldn't be kept with the brackish/marine setup that the Columbian sharks would like/need - these may not need a true marine setup when adult, but they certainly are found in true marine conditions in the wild, and will not tolerate soft water well at all when mature - which is probably part of the reason you never see mature specimens in the shops, most people don't understand that these fish need at the very least brackish water.

Edit: And even when keeping 6 P. pictus, they weren't exactly VERY ACTIVE in my tank - usually hiding, unless food was on offer.

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Mats

[000]

Thanks. I'll be saving up for bigger tanks. Walmart probably wouldn't sell too many fish if people actually knew what some of them require lol.

[apistomaster]

000,
With such a small tank and the budget constraints you stated, why not consider going with only very small species of catfish and anything else you might like? A 14 gal tank can make a great "NanoFish" display tank.
There are some very small species of SE Asian or South American species of catfish. Many of them are inexpensive and also very interesting.

[Viktor Jarikov]

MP: Regarding salt tolerance in freshwater catfish - if I add that to P. pictus, I should got through about 2400 of the 2533 species we have in the Cat-eLog and add it to them too, because nearly all freshwater catfish [which is nearly all of them] are not tolerant to salt.

VJ: Mats, I'm sure you know what I meant but what you said probably needed to be said. From the way it read to me (perhaps erroneously), P. pictus came out as a salt-intolerant fish. I guess, I somehow missed the overall context and focused on how absolute the statement sounded: " ...And do not tolerate salt in the water..."

Yeah, I also imagine that the never-ending, constant suggestions of "wise guys" like me about "improving" the Cat-eLog must irk the mods like you, in all likelihood.

I like the rest of your edifying points.

[MatsP]

Don't worry, I can "take" suggestions that improve the Cat-eLog, and defend "bad" suggestions... My initial statement may not have been put clearly enough, so it's good to ask for clarification.

Walmart probably wouldn't sell too many fish if people actually knew what some of them require lol.

You know this is very true - and not only Walmart, but many of the chains of "Pet stores" also sell fish with limited or no information to the keeper as to what they need for the fish's wellbeing.

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Mats