What Are Those Things Jr Is Growing? - 10/21/2006
I’m sorry if this isn’t the right place to write out questions to you. I found your site and read a few things, and well I’m sometimes a little impatient about finding stuff. So, I thought I would tell you a little about my fish and see what you think in the end.
<Normally we would ask that you do make use of the info already published before asking. But in this case...>
We started buying tanks a few years ago; started off with a tiny 2 gallon, ended up with a 75. It seems the more you buy the more you seem to need, for one reason or another. One of our first purchases, after the 55 gallon, was a Hexanematichthys seemanni, labeled “ Columbian shark ” in Wal-Mart, and no, we no longer buy fish there. The fish is still with us, along with two more. They are living in the 75 which has become too small because the fish are almost a foot long. We have been trying to find someone to take them that has a bigger tank, so far no takers. The tank has been stripped of ALL things because the fish are violent swimmers. The original substrate has been removed and replaced with sand, which seems to have made the fish quite happy. They dig in the sand and I have seen them eating it also.
Like I said, we have had to remove everything in the tank. The gravel went first because they kept tearing their flesh off. The ornaments went next, because the kept swimming into stuff and it wasn’t pretty to watch, kind of like a bird hitting a sliding glass door. These fish a very jumpy and do not like people standing next to the tank. They swim violently at night too even in the dark when no one is near them. Sometimes they jump up and hit the hood on the tank, and its all glass on the top, its REALLY LOUD. Recently, the heater had to go; we were afraid it was going to get shattered into a million pieces, they kept knocking it loose.
We live in Tampa, Fl., as you can imagine its hot most of the year. The weather has started to change in the last couple of weeks and it has become cold at night. Our thermostat has been kept around 79-80 all year but now the temperature inside of the house has been dropping drastically at night. I read somewhere online that someone else’s catfish had laid eggs when they were exposed to a sudden drop in temperature. Well, after reading so many times how my catfish have never reproduced in captivity, I have a really good question, and I am sorry it took such a long time to get to.
Do you know why one of my catfish just grew an extra set of fins? Do you think there is a small possibility that they think its time to reproduce? I do not know exactly how much sea salt my husband has been putting in the tank, or right now the exact temperature of the water. (He has the flu, and I told him about the extra fins, but he’s too sick to get up and look) Let me know what you think. If you want I’ll charge the batteries on the camera and get some pics. I have older ones, I looked at them this morning and the extra fins were definitely not there before. Thanks for taking the time to read all this.
Cindy
<Do you live near Three Mile Island by chance? Sorry, but I doubt your fish grew an "extra" set of fins. In some species males may develop some added equipment at maturity, but they aren't fins! At least not in the classical sense. At a foot long your Shark Cats are about mature, but a check on Planet catfish did not mention this. Only "females have lighter fins". Read here for some more info. Seems there has been a reported breeding:  http://www.planetcatfish.com/catelog/species.php?species_id=700 . Don>

Preggers Plotosid?  9/22/05
We also appear to have a very pregnant salt water catfish. her and her  mate stay together-in a 139 gal tank with community fish-we need to know if the eggs will survive or do we need to separate her or put the eggs in a breeder tank and about how long does it take any information you have to share we will appreciate.
                    thanks
<Not likely pregnant... unless very large... another (male) present to fertilize... See re Ariid and Plotosus lineatus on WWM, fishbase.org... the Net period. Bob Fenner>

Breeding Arius seemanni
I have two Arius seemanni (Columbian sharks) in a 55gal tank. Their tankmates include silver tip tetras, zebra and leopard danios, blue German rams, mollies, and angelfish. I know that some of the species are not the best tankmates for various reasons as ph, salinity requirement later in life (the sharks), and predatory reasons.
<Yes>
However, my sharks are the most peaceful fish in the entire tank! Everyone gets along wonderfully. Now, I had originally started out with just one shark, and then I picked up another a few months later. I know they don't like to be alone. I have another 55gal that I can setup for them. I was wanting to know how to go about attempting to breed my sharks. I have raised various other tropicals, but I really would like to try my hand at this challenge. Any advice would be helpful!
Thanks in advance!
Sincerely,
Theresa
<Interesting quest. I don't know/think this ariid catfish has been spawned in captivity (all are wild-collected as far as I know). A few notes: the genus of this fish has been changed: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=13480&genusname=Hexanematichthys&speciesname=seemanni
Adults live in seawater, they are likely mouthbrooders, with the males carrying the eggs, developing young (till their yolk sac is absorbed or perhaps beyond) in his enlarge buccal cavity... females develop "claspers" (protuberances about the ventral area) as a sexual distinguishing feature. Bob Fenner>