Forum Replies Created
-
Posts
-
1. “Is it possible to estimate the age (or better: date of hatching) of young paros by taking the size as basis? who ag high or low is their growth rate in the first weeks of their life? Are there differences in the various species and forms?”
All definite answers telling a length or a time rate are wrong; they neglect the decisive point. The growth of young Paros depends from the quality of the milieu/the care/the food. I know young Paros which grow extremely slowly, and I know others which grow much faster. In general, the growth of Paros is slower than the growth of many other aquarium fish. But in most cases this is a function of the breeder’s care. We have one very skillfull breeder who manages to get the fastest rate of all, especially in later stages of growth, but in effect his fish sometimes are not the most stabile and sound. Mostly, the quality of the care is at a medium level. If you change water more often, the growth will be accelerated, as it will be if very variable and good food is fed. Important is the space, too. If there is too much space, the young fish will have difficulties in finding food, if there is too little they will suffer from the crowding effect. Mostly, a small space (ten liters in the beginning for about twenty to forty young) in combination with frequent water changing is the best. After about four weeks there should be more space, however.
We do not know of substantial differences between the species and forms. The important factor is that mentioned.
2. “The second, much more comprehensive question is about the determination of the gender in fishes. I heard that there is no chromosomal fixing of the sexes during fertilization, but that the gender evolves in the first few weeks after hatching. Is this true? And – concerning paros – at which age or within what time frame will the gender be fixed? Are all young paros male-coloured and dismiss this colouration when becoming female?”
Indeed: In fish, there is no genetical fixation of the sex. The milieu will contribute to that decision in many respects: temperature, pH, the degree of humic substances are the most important factors. This is a complex feature that cannot be summarized to a simple rule; the process cannot be simplified to naming a number of weeks (see my reply to your first questions). Often, we have broods with 90% of one sex only. To avoid this, try to raise half of the young at lower pH and lower temperature and using less humic substance, and the other half in the opposite way. But this is theory, nearly nobody will follow it.
The opinion that all young Paros are male-coloured first is nonsense. In a way the opposite is true; but this only means that the colours of the males will develop in course of time. I you see an eight weeks’ Paro without any colour, you cannot be sure it’s a female. With some species you will see this development of the colours rather early. If a very young nagy develops blue stripes in the dorsal, it’s a male.
Copper is a heavily toxic substance which should be avoided in an aquarium at any means. It’s nonsense to speak negatively about “chemicals” and positively about copper.
In Germany we use “Flubenol” against Hydra with a success of 100% and no risk for delicate fish at all. I do not know which is the name for the white powder in other countries. Mixed substances which are composed of that substance including others for the sake of other purposes should be avoided; try to get the pure Flubenol. It may be diffcult to find; you certaily will not find it in pet shops. Try special chemical dealers in the internet. The smallest amount will be enough for many years.
Using it in practice, you only need the smallest amount of it (a knife’s tip), it will spread over the water surface immediately and two or three days later all Hydra are gone. Hours after application you see the first reaction already. Even if you use it in double or triple quantity it will do no harm to the fish.
With any form of copper you play vabanque with the ecosystem of your tank.
The fish on that bad picture are no gunawani. I bred the only certain fish of this new species whch I received from Horst’s (Linke) private import, still called “spec. Danau Rasau”. They were conspicuous, far more than most other bintan-like forms frum northern Sumatra.
It’s a well known method of the fish-trade that they take an interesting name especially of a new species to get their fish in the market. Themselves, they are unable to distinguish the Paro-forms properly. The old tactics, to call all of them “deissneri”, does not work any longer. People are better informed now and know that this name was wrong in each of the many cases. So, the newest name is the most interesting one that guarantees the fish being bought.
Traders in south east Asia sometime get huge quantities of one species from one or several catching places when the catchers go there some moths after the spawning period. One thousand is not rarely the number, sometimes more, often less. To get these “difficult” fish sold is really no an easy task. An interesting new name helps.
Dear Marcin, this is a risky procedure and I do not recommend it, at least not in a general sense. It might work with sumatranus, since we have this peculiar feature that these fish look similar to the bintan-group, but display head-up! In both sexes! Therefore I assume that the male will not take other females and the femals no other males than sumatranus. But in nearly all other cases (species/variants/forms) the mode of displaying is head down and we can be not sure at all whether the males of A will definitely choose females of A only, and vice versa. Therefore we try to avoid such a situation by strongly advising all friends not to take the risk of a soecies-mix. Maybe, the males/females themselves are more clever than we are and recognize the right partners even when we are unable to do so. But who knows?
Therefore, I should recommend to give it a well-controlled and -documented try with sumatranus, but – please! – not with other Paro-species!
The pics of Edvet don’t show P. sumatranus but a form of the (Sumatranian)-bintan-like variants.
The short (!) filament in the tail of sumatranus must be visible in fish of that size; it’s 1 mm only, but here it’s not to be seen at all.
The rounded spot to be seen in some individuals is not conclusive of sumatranus; it is present in some bintan-variants, too. It is much more distinct and peculiar in sumatranus.
Bartian, I could not reply earlier. The male fish in photo 2836 is without any doubt a P. sumatranus. Even the small filament in the end of the caudal is well to be seen.
The other fish in the next picture is – I am afraid – definitely no sumatranus. I cannot say which species it is; it resembles a bit a poorly coloured anjunganensis, but it maybe quite a different form, even a hintherto unknown. I suppose, it’s a male too.
It is very rare that shops mix different species. They probably haven’t done this in the Netherlands but they will have received the fish in a mixed bag. This is rare, too, but it happens. You should try to get some sumatranus-females, too. P. sumatranus is one of the most interesting species we know, since it is coloured in the bintan-like manner, but displays head-up similar to ornaticauda. Sometimes, it will even stand still more upright, really in an angle of 90% (defiitely vertical)!
It would be of great importance to build-up a new stock. Several years ago, Karen Koomans from Nieuwe Pekela ha a big stock, but all are lost in the meantime.
Yes, we know of two serious accidents with glassworms from the trade. One of our best Paro breeders in Germany lost nearly whole of his valuable stock – self caught pairs with a definite locality – by feeding them such food. Normally, he would have never done so without “washing” them before, but there was a breakdown of his self grown food cultures (it sometimes happens even to experts) and so he fed them at once. Next day nearly all of his fish were dead.
We have seen this in another case again.
Be well aware of this danger; the trade treats the small containers full of living and half-dead glassworms by adding several medicaments. The same holds for red mosquito larvae or tubifex; no food at all for Paros.
I have never seen any Paro come to death by a mosquito larvae too big; they try to swallow them, but if it proves to be too big, they leave them again. They can eat very big food, it’s astonishing.This is a larvae of one of our big dragonflies, presumably an Aeshna spec. It will kill even adult newts and fish of more than ten centimeters.
Get it out! They are not to be compared with those peaceful shrimps!That’s nonsense. Think of the minerals und nutrients in the pot of those house plants; they change your water, forget it.
Moina are a very good food for Paros, and they are very easy to grow rapidly in shallow containers of two or three liters, fed by yeast or volvox algae (which make the culture less productive but more stable). Paros eat Daphniae too, but they don’t love them (too hard) and won’t become fertile by them.
Black medium grown mosquito larvae are best together with small or medium glassworms, and from time to time Grindal. Vinegar eels are a good food for small young but not really for adult Paros, although they love brine shrimp naupliae. But they are too small as main food.These are typical Sumatra-based types from the Blue-Line- and -Sentang-group, closely related to bintan. Nobody can say this more exactly, since we have an unclear close relationship between bintan and those bintan-like forms that occur on Sumatra. Most commercially traded Paros of the last years came from Sumatra, mostly bearing fictive names (like “deissneri”).
Hello Martin, originally we planned the first international meeting for the year before last year, October 2012. But we had to cancel it for several reasons, one of it was the fact that it was unclear of anybody from abroad would be able to come.
Now we plan that meeting for the next year, 2015. Bill Little from the U.S. has announced that he will attend, very good. I hope there will be somebody from Asia, too. The exact date is not yet fixed, however, but it will be in the warm season (maybe June). And it will happen in Hamburg. We shall announce it definitely this summer.
Hope, we shall meet you and others there?!
(To all: Don’t forget to participate in the running census!)
I had P. gunawani mayself from Linke’s import some years ago and bred them. This fish is not gunawani.
Obviously, the exporters try to make their fish more interesting by naming them with attractive names. That’s a marketing strategy, I am afraid.
But nevertheless: These fish can be wonderful Paros, but what species they belong to could only be said with very good pictures of adult males in breeding colours.P. spec. Dua is a bintan-like form collected by Horst Linke on Sumatra two years ago. He forwarded the animals to me, but I had not enough space for them and so I forwarded them to Bernd Bussler. He has managed to breed them (as he nearly always is able to do) and now he has quite a nice stock of them.
