plesner
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June 17, 2015 at 5:23 pm in reply to: Comparative life histories of fishes in the subgenus Limia #354807
plesnerParticipantIf/when this becomes available, I’d love to read it.
plesner
April 24, 2015 at 5:52 pm in reply to: Trade of ornamental crayfish in Europe as a possible introduction pathway for important crustacean diseases #354516
plesnerParticipant@Matt said:
Thanks for the link Karsten. Are infected animals treatable at all?I don’t have any personal experience with treating crayfish plague. According to a number of texts found using Google, it does seem that they are treatable.
April 23, 2015 at 6:19 pm in reply to: Trade of ornamental crayfish in Europe as a possible introduction pathway for important crustacean diseases #354497
plesnerParticipantA couple of years ago, I translated a German article on Procambarus fallax f. virginalis (Marmorkrebs) into Danish. I did it just to do my bit to spread the word on the possible danger of introducing Aphanomyces astaci (crayfish plague agent) into native waters by keeping the aforementioned crayfish in captivity.
The German article can be found here.
plesnerParticipantWe aren’t going for a biotope aquarium as such. We’re just trying to use fish, plants and so on which are different from the ones we always tend to see and thus try to restrict ourselves geographically just for the fun of it. I know full well that rainbows are found in countless different biotopes.
plesnerParticipantI just received a picture of yet another one of the pearl gouramies. Though it’s fairly small in this picture, it does look a lot worse than the other ones.
February 20, 2015 at 4:07 pm in reply to: Copeia Volume 103, Issue 1 (March 2015) – issue in progress #354210
plesnerParticipant@Stefan said:
Wouldn’t mind copies of:
1. Effects of Water Chemistry on the Life History of the Least Killifish Heterandria formosa and the Absence of Evidence for Local Adaptation http://www.asihcopeiaonline.org/doi/abs/10.1643/CE-14-042I’d love to read that one, too.
Best,
Plesner
plesnerParticipantSome 20+ years ago I witnessed what was surely breeding behaviour in Botia almorhae. This happened while a couple of mouthbrooding Bettas in the same tank were busy breeding. I’m sure they released some hormones or something similar into the water, which triggered the behaviour in the Botias.
It makes sense that using water in which a fairly close relative has just spawned will push some of the right buttons in another species, though I’ve never considered or even heard of this exact method.
plesnerParticipantI can’t help you with any kind of diagnosis, but there is a rather extensive chapter on diseases in Adrian Tappin’s ‘Rainbowfishes ~ Their Care & Keeping in Captivity‘ which you can download (perfectly legal) for free here:
http://peter.unmack.net/tappin/Rainbowfishes.2011.pdf
If it is anything even close to a common problem, you’re likely to find it there.
plesnerParticipantI bred them in the 80’s. I used a 63 litre tank (roughly equal to 17 gallons). I moved a couple of females there a week before I introduced a couple of males. While alone, the females were mostly fed black mosquito larvae. Before introducing the males, I cleaned the bottom of the tank (while changing about 50% of the water). I then poured in enough glass marbles to cover the bottom with a single layer of marbles. Some sort of netting suspended a few cms (1 inch) above the bottom would also work. Fine-leaved plants should also work, though the parents will inevitably eat a number of the eggs.
I would definitely remove the Cory, as I would suspect that it would consider any egg it found to be a welcome snack. I don’t know about the Oto, but I’m not sure that I’d trust it either.
I don’t think you’ll have any luck waiting for a pair to form – that’s not really how they go about their business. In the big tank they will probably breed regularly, but all the eggs/fry are most likely eaten – the exception being that a few will survive if there are enough hiding places for them.
It is possible to make a continuous setup – that is: a tank in which some fry will survive every time they breed and swim to safety away from the parents. To do this, you need to start with an empty tank – preferably one which is a lot longer than it is high or wide. You then glue two pieces of glass on the inside of the tank in such a way that they make a V-shape when seen from above. There should be a small opening (2 mm) between the two pieces of glass where they meet (at the bottom of the ‘V’). Along the bottom, the back and the front of the tank, the pieces of glass should be glued in place so that not even the smallest fry can get through there. The V should point towards the smaller part (about 1/4th of the volume of the tank). You then fill up the tank, place a large handful or two of some fine-leaved plants in the ‘V’. Finally you need to put light over the small part only. When the aquarium has been running for long enough, you put a group of males and females in the bigger section and wait. An air-driven foam filter which lifts water from the fry end to the parents end should be sufficient as far as a filter goes.
What will happen is that the parents will breed and scatter a lot of the eggs among the plants. When the eggs hatch, some of the fry will swim towards the light, swim through the gap in the ‘V’ and be safe from their parents. Now you just need to feed the fry with suitable foods and net them out when they reach a size at which they could be a danger to smaller fry. You may need a second tank for them to grow large enough to survive with the parents.
This setup works with pretty much any species which scatters eggs among fine-leaved plants. It is especially good for species, which don’t produce that many eggs at a time but which breed often.
plesnerParticipantI’ve been running a few daphnia cultures continuously since February 2011. I feed them nothing but green water, which I also culture. They’re kept in two 12 litre and three 25 litre tanks at 20-24°C. When the number of daphnia in a culture begins to drop noticably, I siphon out most of the debris from the bottom and in the process remove about half of the water, which I then top up with fresh water – this happens once every 4-6 months. The water and debris, which I have siphoned off into a bucket, is left for a few days. I can usually harvest a decent amount of daphnia from that bucket, too.
I culture scuds (Hyalella azteca) in neighbouring tanks and all my daphnia cultures contain some scuds as well, but most of my fish eat them anyway.
plesnerParticipantA golden form of this:
https://www.seriouslyfish.com/species/barbodes-semifasciolatus/
September 22, 2014 at 8:33 pm in reply to: Ichthyological Exploration of Freshwaters :- An international journal for field-orientated ichthyology Volume 25 Number 1 #353539
plesnerParticipantI’d be very interested in
Low, Bi Wei, Heok Hui Tan and Ralf Britz:
Trichopodus poptae, a new anabantoid fish from Borneo (Teleostei: Osphronemidae)if anyone has access to this.
plesnerParticipantThat would be my guess.
plesnerParticipant@nuchal man said:
This is a male Astatotilapia aeneocolor. They are similar and closely related to the Victorian haplochromines but are found in Lake George and Lake Edward and the Kazinga Channel which connects the two lakes.Thanks a lot. That seems to be absolutely spot on.
June 23, 2014 at 5:48 pm in reply to: Fry from Phallichthys quadripunctatus at around half their normal size. #353225
plesnerParticipant@Matt said:
Hi Karsten, it does looks like this has been observed in some other poecillids. Check here and here.Thanks a lot Matt. I’ve read the first one, but the 2nd one requires a login.
Well, it seems that my Phallichthys quadripunctatus do behave in a similar way to some of those mentioned in the first paper. What I find interesting is that a change from live foods (microworms, freshly hatched artemia and sieved Daphia pulex) to good quality dry foods had such an impact in just a couple of weeks.
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