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Preliminary Experiences With Rhinogobius zhoui

Home Forums Fresh and Brackish Water Fishes Preliminary Experiences With Rhinogobius zhoui

Viewing 15 posts - 76 through 90 (of 106 total)
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  • #348957

    Ferrika
    Participant

    Bare bottom is not without danger for the larvae when they still can not move properly. The zhoui hatch often too early with too large yolk sac. When they lie motionless on the ground, they are immediately eaten by bacteria.

    #348962

    Matt
    Keymaster

    Great info, sounds similar to the issue with loricariid fry we were discussing a few weeks ago? Good luck with the eggs Mike!

    #348967

    mikev
    Participant

    Thanks for the info Ferrika,

    I had this issue with R.diospilus fry, I solved this by using a fairly strong air stone the following time, let me try the same here, plus a bit of meth blue.

    Matt, not the same thing… loricariid fry tends to be mobile even when still with yolk sac, the problem I had with sturisoma was that they may easily get bacterial infections later. Rhino fry unfortunately is programmed to stay put until the sac is consumed, and I think it was fungus that attacked them! — it will grow on immobile objects. Disparis fry, incidentally, has even larger yolk sac and also took about a week to consume it, but they moved enough.

    #348969

    Plaamoo
    Participant

    Good luck with them Mike! I found another duospilus fry in an aquaclear filter while cleaning. Also found my big male dead. I’m sure he starved while protecting eggs.

    #348972

    mikev
    Participant

    Thanks Jim,

    Will let you know…. so far it seems that one egg just disappeared while the other nine developed the black dot disease … each has two tiny black dots close to each other… we’ll see. And the male is pissed off at me… he made a pile of gravel in front of the cave, effectively sealing it off .. looks like a political protest?

    Duospilus I cannot get to spawn… :( they reject all caves being offered, even the one identical to what zhoui use. Sorry for your male… but doubtful it is from starving, any healthy fish can manage a couple of weeks w/o food, and gobies are built for it….

    #348975

    mikev
    Participant

    Actually the 10th egg fell out to the bottom of the container..looks like this:

    http://www.micropress-inc.com/fishpic/z-eggs-eye.jpg

    Notice two small black dots below the yolk sac.. so the head sticks out of the egg now..and I think I could see tail sticking out on the other end (could have been filament too). Only 3-4 days of development.

    #348984

    Ferrika
    Participant

    The small black dorts are eyes, Mike :-) It’s not so good that the eggs are dropped. You now have to move them very well, so they can still slip.

    #349017

    mikev
    Participant

    Definitely not good about dropping eggs, but I cannot help this really, they drop by themselves.

    Here is the mating pair btw:
    http://www.youtube.com/watch?feature=player_embedded&v=J-MOUv8rMBA

    This female is nearly as colorful as the male, the other two are much plainer.

    #349080

    mikev
    Participant

    If you could describe very briefly just how you use a breeding net, I’ll appreciate this!
    (the fry on the bottom does not last, they die before finishing the yolk sac, within 3 days of dropping down. :( This was not a problem with r.diospilus or other bottom fish fry with large sacs I dealt with before, like disparis. I have more eggs now and will try net .. but do you use an established tank? how do you aerate–under net? meth blue? this kind of questions.)

    #349082

    Ferrika
    Participant

    I hang the net easily into an empty 12-liter tank. Before the net is a small pump (200l / h), which is reduced to minimum. The CLUTCH is treated with FMC (3 drops per 10 liters). The basin is simultaneously filtered with a sponge filter. Water is changed every three days, FMC postdosing.

    After hatching, the young stay in net until the yolk sac is used up completely.

    With the FMC-treatment of the clutch, the slip is also regulated. The young hatch not too early and the yolk sac is then no longer be so great that the kids can not move.

    #349087

    mikev
    Participant

    Thank you very much for the info; I’ll try net in a 5g (20 liter). let me pass on fmc this time, I don’t have this specific product and while i can use some other similar Ich medication, the dosage will be different.

    #349164

    mikev
    Participant

    One more question if I may: can you raise the fry from subsequent spawns together or the younger fry would get eaten?

    They seem to spawn about every 15-20 days, so this is the interval.

    I tested this a bit by putting newborn aspidoras with the oldest zhoui babies (free from yolk sac for maybe three days now).. aspidoras were half the size of the gobies and I cannot see them anymore :(

    http://www.micropress-inc.com/fishpic/rzhoui20d.jpg

    The net idea was a good one, thank you!

    #349166

    Ferrika
    Participant

    I prefer the little ones always about 4 weeks apart until the youngsters are so strong and nimble that they go their siblings at risk out of the way. Then I put it all together without any loss.

    You assure out, however, to feed all the gnomes at least twice daily.

    #349170

    mikev
    Participant

    I’m trying to feed them a little 3-4 times. I even do this to the 2nd group; they currently have yolk sac about the size of their heads but show interest in artemia… two were hunting it already yesterday night, and more today. No way to know if they are eating it, but at the very least let them exercise a bit.

    On breeding net: no doubt it is essential for their survival. However, I do not believe that bacteria is involved, and I don’t understand what is!

    Here is what happened to the first 10 eggs I had: they started dropping down and dying within 48 hours. When i was down to three, i put them into a breeding net in a tank with other fish (the later spawn is in a net in a clean new tank, but the first time I had to move fast and did not have another tank available.) while the tank looked clean to me, the net accumulated a lot of dirt during the week the fry was in it, I’m sure the fry got exposed to a lot more bacteria than in a sterile container. However, all three survived! So if not bacteria, then just what?

    Now, in the 2nd group it seems that all eggs that dropped survived so far. But (?!) a few did not drop and died attached to the cave… so dropping is perhaps right!

    Need to experiment more when I have ‘nuf of them.

    And one more realization about them: I have 3 pairs… but it seems that only one pair is breeding, the other four are just living in the tank. Too bad I’m too short on space now, moving the bystanders to another tank possibly would produce another breeding pair.

    #349171

    Ferrika
    Participant

    Now, in the 2nd group it seems that all eggs that dropped survived so far. But (?!) a few did not drop and died attached to the cave… so dropping is perhaps right!

    It may be that the eggs that have not been dropped, were simply not moving enough. Therefore I put the plate with the eggs always vertical into the netbox and let a small pump gently blow directly on the plate. These eggs will not die.

    It may also be that the eggs have benefited in the inhabited tank by bacteria functioning. I imagine that in a retracted tank water quality is better than in a bare, freshly put breeding pool.

Viewing 15 posts - 76 through 90 (of 106 total)

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