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Hara Jerdoni

zozo

Member
Joined
16 Apr 2015
Messages
8,643
Location
Netherlands
The Asian Stone Catfish wonderfully and very beautiful little fish.. :) Recently i got 5 of these and definitely going to get more. If you have them in little numbers you're lucky to see them by lights on and if, they are not realy putting up any show. It's not uncommen you need to wait an hour before you see them move a milimeter.

But still they have a very beautifully patern, actualy if yo get the chance to see and inspect them all. You might identify them individualy by patern differences. The most beautifull feature this little fish posseses is something i didn't read about in any database, not that i red them all, but it still would be worth to point that out in every one of them.

They are like chameleons and change color. The day a got them they where all black as the night.. And by now i've seen them change in several different color tones. From black, to dark brown to camel brown and grey/greenish almost a pinch of torqouise. The most of these colors i got in the tank, the multi tone brown colored wood, black and grey substrate and soem rocks that have this pinch of gray/blue tones. No wonder they are so hard to spot sometimes. :)

Here is the grey/blue dress i saw today for the first time.. :)
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As said, it's a bit of luck to see them at all when lights are on and have them possing at a spot where a nice picture is possible is even more a rarety. Most of the time they are out of sight or at spots not suitable for pics. But i'm certainly going to try to get all their color variaties they have to show in my tank on photo.

Do you have them also?? What colors have you seen?? Do you have pics of it?? :)
 
Wow, just read the Seriously Fish article, those guys are tiny! I would love these, but it says they are easily out-competed by other bottom dwellers, so I guess these would not do well with my Cory Sterbai.
 
but it says they are easily out-competed by other bottom dwellers

I have no idea how i have to interpret that and would like to know some more details how they came to this conclusion. I have them together now with a bunch of barbs, which are highly active 24/7 exclusively eat at mid to bottom range, don't even look at floating food, have a unsatisfialble apetite, whatever food i throw in the tank, what i can see is all gone in no time. I feed them froozen food and vipachips which is a sinking chip, i crush it partialy to powder and throw it in.

Anyway those hara's i mainly see become more active at twilight, so as seriously fish states too, i feed also at that time. They seem to be omnivorous and also see them munch on spirulina i sometimes throw in. But most of the day the don't move an inch, i guess if they where that hungry they would certainly search for food and not just lay there waiting to die.

In my experience :) a good and mature not over stocked tank provides more food than you would think of and 90% of the fishtanks are actualy over fed even if we don't perceive it like that. There's (live) food in every healthy tank we barely can't see with our nacked eyes. I feed my fish very little food if i compare it with the amount what i see other throw in i'm at 1/10 of that and oftenly skip a day.. Still i have for example the very skiny juvenile black terta's i bought 4 months ago grow to almost adult size in this short periode and still are healthy and growing. Making your fish and critters work, compete and search for food, like stirring up some debri also contributes to having a healthy tank. ;)
 
Here it is in nearly black dress, The color they all arrived in was darker and more peppered with white spots..
DSCF5857 (Kopie).JPG


And the camel colored version..
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Here 2 together, the blue one from yesterday ??, the other decides to make it olive green today but seems to match its mustage with it's neighbour.. :) You see the marking on it's fore head is different. I'm trying to figure out if i can identify individuals by these markings or if they chance to.. Fascinating little fish.. :thumbup:
DSCF5874 (Kopie).JPG
 
INspired :D

I've asked my friend to add these to the import list :)
 
It's a fascinating tiny fish, i did read some reports on it color change and this is actualy nothing but a little side note. I never had them before and maybe it's just coincidence in the way i did setup my tank, with multicolored DW, greyish rocks and a mutlicolor black gravel. This could be the cause why they can't decide what color to take and switch it all the time.

But in my opinion, this color changing is not to be considered a side note but actualy the main attraction these little fish have to offer. It makes it so much more fun to sit in front of the tank knowing they are hard to find and search them with looking very closely. And then find one at a place you looked 3 times before. :lol: And be again amazed about them. :cool: The other positive side is, you see other things you might not notice otherwise because there is no reason to stare into your tank and search for something. :cool:

Now i also did read that they do not only respond to surroundings with their colors but also diet plays a role.. I feed rather diverse with a variaty of froozen food, a sinking pellet and spirulina. I seen one taking some of that spirulina wich has that distinct dark green color, actualy matching the green color of the one in the last pic.. :) Just to funny, could it be the one munching on the spirulina the day before?? I wonder if i will get them pink :woot: if i feed them only brine shrimp for a while.. :lol: This would certainly ascalate the number of women going in to this hobby.. :lol:

No seriously for me this is the best buy i did since i started this hobby again.. There certainly will be more Hara Jerdonis to come for me..:thumbup:
 
I just checked with my LFS and they say these are usually readily available and they can try to order them in for me. Need to get my rescape out of the way at the end of the month before I add more fish, but hopefully I can get some ordered in during March.
 
Hara Jerdoni Nocturnal? Or hiding a lot? Not if yoy feed them Aquatic Micro organism.



Mine go nuts on the crustaceans and rotifiers i feed daily scooped from an outdoor bucket filled with water, moss and leaf litter. Any time they are all over the place.. :)
:thumbup:

Very hard to catch on camera when they deside to be active. Just to fast and to small..

But darn Hansom.. :)
DSC_0352.jpg
 
Hi all,
Hara Jerdoni Nocturnal? Or hiding a lot? Not if you feed them Aquatic Micro organism.
That is really interesting, the way it turned upside down at the surface makes you wonder if they often feed like that in the wild.

This may well be a unique video of this behaviour. Could you post the video on "PlanetCatfish" (or I could post the link?) There are quite a few scientists etc who post on there who might be very interested in that as feeding behaviour.

Not closely related, but I know some of the S. American Oil Cats (Centromochlus perugiae) are specialised surface feeders on moths etc.

cheers Darrel
 
Hi all, That is really interesting, the way it turned upside down at the surface makes you wonder if they often feed like that in the wild.

This may well be a unique video of this behaviour. Could you post the video on "PlanetCatfish" (or I could post the link?) There are quite a few scientists etc who post on there who might be very interested in that as feeding behaviour.

Not closely related, but I know some of the S. American Oil Cats (Centromochlus perugiae) are specialised surface feeders on moths etc.

cheers Darrel

Be my guest if you want to share my content. :) There is no copy right and happily help anybody interested.. But i'm quite convinced this is feeding frenzy.. Since i'm keeping these fish for 2 years now and never seen this behaivor before, till i started feeding daily with small life micro food from a few fishless tubs and buckets i have in the garden. And since then they are extremely active all over the place and what the video shows i see every day. :)

Please share the link, i'm very intersted in the replies. :thumbup:.
 
Very pretty fish!

You'll find many fish change colours depending on the environment and conditions. My polypterus and African knives change colours every now and again. But just different shades of olive or brown :p
 
I took out the Oldschool microscope and attached an old camera. :) To have a look what in that bucket the Hara's go nuts over. I think it are kind of rotifer and there are numerous of them in there, very tiny, if i have to size them with teh naked eye i would say maybe less then 0.10mm but i see them. Anyway they are so small they almost fall through the mesh of a small net. For example can't catch them with a tea strainer mesh. WIth a cloth mesh they stick to the netting. And with a few scoopes i have maybe a few 100.

Unfortunately the old Nikon camera on the microscope is to old to film it only takes pictures. And for now i didn't manage to get it any beter than this.
But i think it must be these.. The biggest i can find under the mic. :) Also find things even smaller.

Funny actualy how they seem to cluster in thight groups. Maybe stres reaction betwen the glass slides, in the bucket they seem to be free swimming.

DSC_0362.JPG


DSC_0365.JPG


In the aqaurium they like to bounce up and down the glass, i guess it's the bio film attracting them.. Also had them in a small shrimp tank a while ago where they did the same always gathering against the glass paneland near te substrate. But this tank has some goldfish babies added and all is eaten now..

Remarkable is i have a bucket and a tub in the garden. The bucket is littered with these blighters 1000nds and some mosquito larvae. And the tub only contains daphnia and mosquito larvea, but non of these.

And as far is i can see its the Hara go bonkers over these (Assumed) rotifers and go extremely active when i add this to the tank, definitively fanatic micro predators.
 
For size comparance, this is a very young daphnia barely to see and not recognizable as Daphnia with the nacked eye, just an active tiny dot.
Thus for us, the others also abundand present clustered like this they look like free floating dust specs.

Anyway definitively food for a 30mm fish like a Hara.. They all go frenzy and hunting adding this to the tank.. :)
DSC_0362-m.jpg


Seen more sp. hoovering around in a bucket with water with leaflitter added. Looks like nothing to us, but it contains a party for small fish triggering intersting behaivor.. :)
 
Hi all, I think they may be a stalked ciliate protozoan, something <"like Vorticella">. They are like Diatoms and Rotifers and pretty much universal in fresh water.

cheers Darrel

That lookes quite like it.. Thanks.. Pitty i can not film it with that camera.. Intersting little creatures and how they cluster. Sometimes i see lttle groups of maybe 5 or 6 clustered symetricaly like a little wheel with spooks around an axil. Just not turning but floating around like a little snow flake Than i see one lash outwards and rectract back in position. No idea why it's doing that.. It looks like it's hunting as well and catches something even smaller i can not see with this magnification.

:)
 
Interesting isn't it. The way they group together perhaps gives some insight in to the origins of multicellularity.

Absolutely.. :)

It is this what i see (From Darrels link above)
contraction.gif


And i see them also do this in team work, as said a few kinda linked together with their peduncles attached forming a wheel shape formation. Then they atract and detract almost in sync at least always a few togheter creating a greater suction to feed on even smaller organism.

It's amazing and mind boggling. Teamwork in micro organism. I realy need a more modern digital microscope. :) Oldschool is fun, but now my eyes kinda hurt gasing through a tiny hole into a light. :confused: Respect for the oldschool biologist doing this all day long..
 
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