RSS Facebook Twitter YouTube




A couple of rhino questions for Jutta…

Home Forums Fresh and Brackish Water Fishes A couple of rhino questions for Jutta…

Viewing 15 posts - 1 through 15 (of 125 total)
  • Author
  • #302618


    i hope you don’t mind the bother… I’m toying with the idea of another rhino tank, and it seems that the availability includes these species;

    Rhinogobius henchuenensis
    Rhinogobius candidianus
    Rhinogobius foromosanus

    (I looked them up on your site … all look interesting enough, actually, this is why your opinion for the best one is being sought….of course chances of breeding is a big factor).

    And also: i’m still getting nowhere with rubros… they are only eating, not interested in anything else. At least they are much prettier now…. I’m wondering if reconfiguring them may help? The group is 4m/2f (I did sex them right… the smallest male was masquerading as a female).. perhaps getting two more girls and splitting them 2m/2f per tank would help?

    Thank you!



    While you’re at it Mike, what do you guys think this is?




    Hristov posted a better pic of it on facebook today. It showed what looked like breeding colors, nice!



    These Jim? Think the fish posted above might be female and this one her boyfriend? Currently identified elsewhere as R. cf. nandujiangensis. Apologies for the semi-hijack Mike, can split this if you prefer.





    Hi Mike,
    All three types have their own charm.
    R. formosanus are the most colorful of the three, the greatest good with 12-15cm. They are very peaceful, but the larvae need when raising saltwater and Brachionus. Which are very small. My currently do not have tails anymore because I’ve taken too early from the salt.

    R. candidianus are very charming, but a little more aggressive, within species as well as across species. The larvae are easy to pull great because although floating free, but very large and eat immediately Artemia.

    R. henchuenensis are my favorites. Slightly smaller than R. candidianus (8 cm), relatively peaceful get very rare and easy to grow, because the larvae hatch also quite big and eat the same Artemia. A beautiful species.


    Regarding your R. rubromaculatus, I’m pretty clueless. I’ve never seen that they not reproduce want, the opposite. I e.g. currently about 30 animals in a 100 x 50 aquarium, but the increase nevertheless. Could it be that your animals come from a breed that has been made infertile with medications?

    Of course you can try your luck with two additional females, but I fear more, because something else is wrong.



    Matt, your question I already answered on FB (or rather, Hristos question Wink)



    Aha so the id was from you. Ok perfect. :)



    Thank you very much, Jutta,

    It sounds like R. henchuenensis is the best choice. What do you mean by “get very rare”, however?

    As for my R. rubromaculatus: it is not the fertility, they simply are uninterested in spawning… in fact, the males are not interested in females, or even in impressing each other. The most I see is that once in a while a male goes into the cave, but would not stay there longer than a few minutes. :(
    Most likely I’m doing something wrong… maybe too hot at 75F? or maybe the cave is wrong (but then the males still should react to each other)… or live food?



    24 ° C is actually a good average and not too warm. What do you feed them like that? Bloodworms? White mosquito larvae? Black? Tubifex? Artemia? It should preferably be a mixture of everything, live or frozen.

    The rubromaculatus don’t care for water values. They multiply really everywhere, whether soft or hard.

    Incidentally, it is this: if the males are infertile, they care not for the females.

    What you could try again: just let them a little hungry and, the water somewhat filthy. About two weeks no water change and to feed every three days. (In the time you have as much howling at other aquarists that the stupid critters not spawn and loudly complain that you will give them away to beginners, if there were not happened at last something! That’s Part of the ritual Laugh). Then you make a large, cool water change and feed them vigorously with live food (not just blood worms!). Then you make once every three to four days large water change and feed them daily vigorous and then we’ll see ….


    Oh yes! The henchuenensis …. Are extremely rare in the trade, so you should take them as long as you can get them!



    Feeding mostly frozen bloodworms and frozen spirulina brine shrimp. I gave them live white worms a couple of times (a friend manages to maintain the culture and donates some once in a while). They are not interested in artemia unfortunately. Feeding is 5 days with 2 off. The males are quite fat… but the females do not look too gravid.

    What kind of spawning place you provide yours? Maybe my cave is simply not to their liking?

    btw, here is a strange story about why it is 4m/2f and not 3m/3f I was trying for: I sexed by body shape and reconfirmed by the color of the rim on the fins… when I brought them home, it looked indeed like 3m/3f, but one smaller fish (thought female) was damaged: side fins were half-gone. And the males were seen trying to bite it… I actually saw a male biting off a bit more of the side fin! … the fish was mostly hiding in the back for a couple of months, fully recovered, and turned out to be another male… now I cannot tell it from other males. So like with some other fish, smaller males may try to masquerade as females… it did it well enough to deceive me, but not to deceive other males.

    Got you on R.henchuenensis — will try, hopefully not too late.



    Hmm,…. just in case: do you know which antibiotics may cause infertility?



    Methylene blue in too high doses in spawning and juvenile fish can lead to infertility, Mike.

    Incidentally, I have now a group R. henchuenensis offspring of my former breeding group get back :-) Pictures will come tomorrow ;-)




    Looking forward to photos and story!

    (No reasons to think they were exposed to high meth blue. May I know what kind of spawning cave they use in your tank? — perhaps what I gave them is just not suitable, even if zhoui’s seem to like it.)



    sorry, I forgot to answer you on your question about the spawning caves. Mea culpa!

    My gobies prefer behind closed tubes and flat, not too thin stone slabs.


    The pica from the henchuenensis must wait. They are a little shy. I must them first a little bribe with good food ;-)



    Well, they have closed pvc tubes now (a couple of sizes) but ignore them… :(

    One more question if I may: any hints on sexing R. henchuenensis? The fish arrived but the vendor thinks they are all males… I have not seen them myself yet, likely in one week, hoping for some hints from you. Thank you!



    In re R. henchuenensis: I have a group.

    The fish seems full-grown and (fingers crossed) healthy. Quite active, and behave like zhoui’s rather than rubro’s: after eating enough, they switch to playing, ignoring the rest of the food (rubros will finish all food and wait for more). I even saw a male making face…impressive. Hopefully they don’t kill each other, they are nearly the same size as R.guirinus…..

    The bad news is that I have 4 certain males plus one near-certain :( I may even have an entire male group. I took all the fish that was available so if there are no females, it is real bad :(

Viewing 15 posts - 1 through 15 (of 125 total)

You must be logged in to reply to this topic.