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#1 Moontanman

Moontanman
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Posted 10 September 2017 - 04:59 PM

I've been doing a bit of tank maintenance, 10 gallon partial water change, plants need to be trimmed back and the trimmed off parts planted.

 

I hope all our friends in the path of Irma are doing well, looks bad on the west coast of Florida be cautious my friends! 

 

I wanted to ask if anyone else keeps popeyed mullets? Most think of them as marine fish but they live quite well in freshwater as well. I have four of them I've had for a couple months of so and watching them is interesting. They eat a lot of sand and excrete it as they swim around in little clouds. The feed well on flake food and tiny pellets and harm no one. They school together and are very impressive fish. 

 

I also have a iridescent shark, I know I tropical fish, but the interest lies, besides my own weakness for fish that look sharky, is that they often stay very small compared to the one meter adults they are in the wild. I've had this one for a year and a half, he eats like a pig, very active and schools with the other fishes but he is only 3" long! I am wondering if there could be some hormonal interaction with some of the native fish that keeps them from growing. I know that certain carp like fish are not supposed to be able to breed in water that contains sunfish.  

 

Just a thought, any opinions? 


Michael

Life is the poetry of the universe
Love is the poetry of life

#2 WThorne

WThorne
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  • Richmond, VA

Posted 10 September 2017 - 10:35 PM

Interesting that your Iridescent shark has stayed so small, I have never seen one that didn't reach at least 6 inches in the first year.  Cool idea about chemical interaction between the fish keeping the size down, Diane Walstad talks about chemical interactions (allelopathy) among plants as well as fish in her book Ecology of the Planted Aquarium. Another idea would be if you actually had Pareutropius buffei (usually sold as Debauwi catfish) instead of a Pangasius species.  These only reach a size of about 3 inches, look very similar to small Pangasius species, and are being sold more and more by reputable shops as an alternative to Pangasius because they are generally hardy and do not reach such giant sizes.  I also hope everyone in Fla. is staying safe.



#3 Moontanman

Moontanman
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Posted 11 September 2017 - 11:29 AM

Interesting that your Iridescent shark has stayed so small, I have never seen one that didn't reach at least 6 inches in the first year.  Cool idea about chemical interaction between the fish keeping the size down, Diane Walstad talks about chemical interactions (allelopathy) among plants as well as fish in her book Ecology of the Planted Aquarium. Another idea would be if you actually had Pareutropius buffei (usually sold as Debauwi catfish) instead of a Pangasius species.  These only reach a size of about 3 inches, look very similar to small Pangasius species, and are being sold more and more by reputable shops as an alternative to Pangasius because they are generally hardy and do not reach such giant sizes.  I also hope everyone in Fla. is staying safe.

 

 

The "Debauwi" catfish is another of my favs, I first saw them more than 40 years ago, great little schooling fish. But no, I am very familiar with both fish and this one is definitely a Pangasius shark. In fact a girl at the pet shop who doesn't keep any native fish and bought several out of the same tank I bought mine from says hers are all well over 12" now.  I'll check out that book, sounds interesting, I'll post a video update of the tank later today if I get the chance. Here is the video of the tank when I first set it up in it's current form a few weeks ago. You do get a glimpse of the shark as it swims by. I have removed all the tropicals now except the shark but they are still in this video. 

 


Michael

Life is the poetry of the universe
Love is the poetry of life

#4 WThorne

WThorne
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  • Richmond, VA

Posted 12 September 2017 - 08:48 PM

Cool tank, you are right, definitely a Pangasius species.  Chemical interactions that would keep a fish that much smaller than it's normal size while still remaining healthy would be interesting, especially if you could isolate what they were.  Could open up the possibility of keeping and observing some species that normally can't be kept in home aquariums.  I think I have a similar effect on fish.  Largemouth bass are supposed to be able to attain well over 18 inches in length but anyone who has ever been fishing with me will attest to the fact that they are rarely over 12 inches in my presence.



#5 Matt DeLaVega

Matt DeLaVega
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Posted 12 September 2017 - 10:02 PM

Some species seem to "stunt" better than others. Gar for instance can be fed sparingly and almost stop growing at 12-14 inches. If you try the same with an Esox species, it will fall apart. Try to feed a 4 inch grass pickerel sparingly and it will get hollow and die.

 

Some say pheromones, some say water changes(which could dilute pheromones), I have no idea really, but i have seen breeding populations of 3 inch green sunfish in ditches right along with 8 inch creek chubs. Conundrum.


The member formerly known as Skipjack





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