Photographing eggs

Yesterday I colllected Austrolebias wolterstorffi (Velasquez) eggs. I just decided to make some pictures of them, using a DinoLite USB microscope with UV (395nm) and near IR (940nm) leds. Here are the results on a fresh egg (well maybe not from the last few days) that I just put straight from the peat onto a piece of paper on my desk. The result is simple to achieve and really encouraging. So I will try to get pictures of all main developmental stages with this lighting. Left: UV; Right: IR.

wolterstorffi egg (UV)wolterstorffi egg (IR)





A. elongatus (Gral Conesa)The coldest days seem to be over now. This picture is from last week. In my barn, most tanks still hold fish. This man is over a year old now, it’s an elongatus “Gral Conesa”. It is overwintering in an unheated garden shed, that does catch some sun during the day. So far, so good.

New tricks

Austrolebias prognathus (Salamanca)A small A. prognathus (Salamanca), some ten days old. I have been worrying about controlling nitrate and levels of other waste products in my tanks, to maximize juvenile growth of small ambitious fish like this. In some places the tap water is really excellent, in others it’s barely acceptable which makes the level of difficulty to maintain some species very variable. I also start believing that local tap water properties really determine how many people engage in the aquarium hobby and also determine the fish species that do well and are maintained in the killifish community. Wouldn’t it be nice if we could make some things “easy” anywhere?

In many situations, replacing water when it’s almost too late can help of course, but I prefer to be ahead of things, to avoid excessive levels to build up or to “clean” the tap water. So I am moving away from tanks with just some peat on the bottom, and I add zeolite now, just a little, to see how it behaves, what the effects are and if it might help to make raising fish easier everywhere. Plans are to measure lots of tanks and different waste product treatments later, in a situation where I start from dechlorinated tap water. Will be some work: all samples will have to be filtered and frozen before they can all be analysed together.

Austrolebias charrua

Austrolebias charrua (Los Naranjales)This afternoon I made pictures of one male and three females of Austrolebias charrua (Los Naranjales). They’ve been outside for almost three months now, and I’m happy to see they do well. Charrua is a real beauty and always a pleasure to find in your net in the field. There is quite a bit of colour variation, even between different generations of the same line. The flanks can be gold or grey, it is unclear to me what would cause that. Females can vary quite a bit in colour pattern, even on the fins. It often happens that I mistake a female for a young male.

Egg drop out

A. cheradophilus (La Paloma 2016)In 2005 I received eggs of A. elongatus “Ezeiza” incubated in  Sphagnum magellanicum and eggs of A. vandenbergi “Talon Cansado” in the same material last year. I decided to give this spawning material some extra attention and offered it to fish as spawning material. For one of the samples collected like this and currently seven months old, I tried to determine the state the embryos were in. To my surprise, that was very easy! After some drying, eggs started rolling out of the moss. For example, the one on the photograph, which is A. cheradophilus “La Paloma”. Will definitely experiment with this spawning substrate further!

Lots of eggs

A. gymnoventris eggs (2016)Some peats are just so packed with eggs  you can’t miss them. This one we’re drying out a bit for an experiment at Foljuif. It’s has been filled with eggs by a group of Austrolebias gymnoventris “Castillos”. If you zoom in, you can see eggs that are still clear, in at least one other you can see the embryo’s eye. We take care that these don’t die while drying the peat.

Winter guests

A. gymnoventris (2016)During winter, I keep a few groups of fish in the house, to make sure they go on breeding and to collect eggs often. The room is heated to some 15 degrees, and receives sun in the winter afternoons. In spring, by the end of April, the fish go into the garden again, or they are replaced by a bunch of more exotic ones. Here a male A. gymnoventris “Castillos” which lives in a group of some six adults. They eat well and produce eggs well. This male is some eight months old.

A vandenbergi

Austrolebias vandenbergi (2015)A picture of a pair received as A. vandenbergi (Talon Cansado), hatched end of January 2015 from eggs received from Ricardo Rojas. They look great, although I expected a more protruding snout, but it might be masked by the bulgy head older Austrolebias can get. The male does get some wear on the edges of his fins now, so I might lose him in a while. November is very warm this year and they continue to lay eggs well. The eggs are quite large for the size of these fish.

More alexandri

Austrolebias alexandri "La Guarderia" (2015)I know, the water is turbid and it’s all not very sharp but among my photos taken yesterday, this one does most justice to the stunning colours of mature A. alexandri. This population is “La Guarderia”. which I keep as of this year The fish are outdoors still in a 80 liter basin and they are some six months old. In a few weeks they will move indoors.

Old Men

nigripinnis Maschwitz (2015)I didn’t check in detail yet how old they are exactly, but these two nigripinnis “Maschwitz” are over a year old. They spent a full summer outside in a shaded tunnel, a winter in the greenhouse and now into their next summer and doing well. Don’t worry about the “thing” looking like a hole in the dorsal fin. It isn’t – it’s a strange reflection. Nigripinnis, the first Austrolebias I ever had. They’re cute, vivid and easy, with deep colours.