Spring season has started. The first juveniles have already been transferred to the garden. In the garden house many fish are still there since summer 2014. They have overwintered without heating. I will read out the datalogger measuring the temperature time series soon. Among the survivors: A. juanlangi Parque Rivera (photo), A. alexandri San Javier, A. nigripinnis Franquia, Villa Soriano, A. elongatus Vivorata, A. prognathus Salamanca, A. bellottii Estacion Sol, Maschwitz, A. affinis R5km399, A. charrua Canal Andreoni, A. viarius Valisas, A. cheradophilus Castillos, Ruta1316.
It’s almost February, time to start raising this year’s new breeders. I’ve started at home, with bags from Uruguay and Argentina that I stored for four months (Thanks Heber Salvia, thanks Ricardo Rojas, thanks Rafael Mitre Muñoz!). The photo is the moment where I put the peat+eggs in small containers with some extra peat. I add half a cm or one cm of 15C rain water. All containers then go inside a small incubator at about 22 degrees C. Result: 23 cheradophilus “la Paloma”, some 15 vandenbergi Talon Cansado, melanoorus Tranqueras, arachan Bañado del Chuy, duraznensis Paso de san Borja, alexandri San Javier, El Bulin and El Pingo. Not bad to start the year with! Some other fish here at home will have to move soon!
I just started a trial for another heating method to store my Austrolebias eggs through winter. I tacked IR heating foil to the ceiling, right above the cupboard on which I store my eggs. Contrary to heating cables I tried before, the foil doesn’t become very hot. The heat radiates well. Previous years, I used to put heated aquaria in between my peat boxes but the warmth never distributed well. My first impression is that this new thing will work better. Soon more on this with the data from the logger I put with the eggs.
Live food, the more there is, the better. Some of my attempts to culture Moina waterfleas failed by copepod invasions or other unexpected events. I now raise them in jars with Pistia stratiotes plants. These are just standing in the windowsill and go fine so far. I do see some copepods in the jars, but they don’t seem to take over the entire culture.
Spring has advanced well, I’ve been hatching alevins wherever I could. For different reasons, I wanted photographs of freshly hatched alevins. At first I always waited until they swam well after hatching. Now I found out I can just as well photograph them while still “bellysliding” and that they will start to swim well after a while if I transfer them to a very shallow tray (or with different water levels) after taking the photo.
Another way to grow blackworm (Lumbriculus variegatus) seems to be on Japanese filter mats. I have a piece of that about 40 by 20 cm in a plastic tank outside. The water level is currently 15cm. The worms have settled in the mat, and I can regularly collect a clump of worms from each corner where they also accumulate. The tank has been outside at temperatures from 1 to 20 degrees, so far without problems. The food I use are spirulina tablets, but I will try to replace that by spinach or other leftover green vegetables from the kitchen. I do take care to regularly remove all other organic material than the food. The worms seem to grow larger than in my indoor culture.
All through winter, I continue to collect eggs from old boxes. Many of them have been stored at 22 degrees or at fluctuating temperatures for several years. Some contain many eggs still, many few. These few eggs are sometimes essential not to loose a line. In the picture, two eggs of A. cinereus, from a peat collected in october 2010. Picture taken today. They will be stored in a small bag during four months at 22 degrees. Then wetted 🙂
Another culture of blackworms is running for two weeks now, and the worms evidently multiply, even at 17 C degrees. It is built from an I*ea storage box with a tray inside. The tray is perforated to allow a pipe to pass (right). A sponge filter with pump takes water from the bottom compartment through the perforation. Water returns from the tray to the bottom via the handle in the tray, which is partly blocked with filter foam. My estimate is that this system contains 20 liter of unchlorinated tap water, and that I will be able to feed at least five tanks from it. The worms live on an around dice of filter sponge (large pores). Food: pellets with a high percentage of Spirulina. Water changes: none yet, but I plan partial changes at 15 day intervals. A third system is already in preparation, more news soon I hope….
Another culture which has taken off well, thanks to the excellent advice of João Mourato, are vinegar eels (Turbatrix aceti). In a small plastic pot with some air holes in the top, add a mixture of oatmeal porridge and vinegar in a layer of a centimeter in total. I briefly boil the oatmeal in water to make the porridge. The vinegar I use is apple vinegar without sulfites added. I add not too much vinegar. When I taste the medium (before adding the starter worms), it tastes slightly acidic, but not too much.
The worms will crawl up the walls of the pot, where you can harvest them very easily. In retrospect, they might be just microworms (Panagrellus redivivus), since it has been easy to maintain them without vinegar also, will check…
After some serious thinking I decided to try a heating mat and a controller, to store my killifish eggs at a more or less fixed temperature at home. It didn’t work. The fluctuations in temperature right above the mat for example went from 24 to 36 degrees, when I just wanted 22 C… So now I’m back to a system where some tanks with an aquarium heater are standing amidst the boxes with peat. Should work, has done so for years.