From 04 Apr. to 06 Oct. 59, I sent out 62 different shipments of eggs.
5488 eggs in tubes and some in peat were delivered to the post.
Cynopoecilus melanotaenia (1022 eggs/39 tubes), Cynolebias bellotti (799/23),
C. whitei (759/20), Pterolebias peruensis (693/14), Aphyosemion calabaricus (393/21),
Nothobranchius rachovi (349/18), N. palmquisti/guntheri (200/6), Aphyosemion sjoestedti (191/7),
Cynolebias nigripinnis (189/8), Aphyosemion calliurum ahli (141/7), A. filamentosum (132/5),
Golden Tail Rivulus (120/8), Pterolebias longipinnis (115/5), Aphyosemion cognatum (98/8),
Cynopoecilus ladigesi (82/3), Aphyosemion coeruleum (77/5), A. labarrei (50/5),
A. schoutedeni (35/5), and Nothobranchius orthonotus "kuhntae" stock (10/1) -
a total of 208 ampoulles containing eggs.
It seems as if most eggs spawned by the "annual" species arrived in good
condition at the place of destination, but the hatching results were generally
rather low, compared with the number of eggs sent out. However, most receivers
at least were able to raise one or more species for further breeding. The eggs
of Aphyosemion gave more difficulty, as they are not mailed as easily as eggs
that do not develop at once after spawning. In order not to place any infertile
egg in the tubes, I had to take the time to see if any egg developed fungus.
Therefore some shipments were delivered to the post at a state where development
of fry showed pigments. Such eggs will be killed if only one bad egg is present
in the tube.
Nearly all eggs were sent "dry" in order to have the largest possible amount
of oxygen inside tube. Very many tubes were blown with pure oxygen, just before
delivering them to the post. As far as possible, I dried eggs so far that they
rolled inside tube in order to prevent them from forming a mass. As far as I
have been informed, the packing in "flamingo foam" proved to be very practical
and I also had several packings returned that still could be used.
Even as my stock in some way has been reduced during the latest months, I should
be very glad to know what species you in particular should like to receive when
further shipments are possible (during Apr. 60) in order to be able to keep breeding
stocks ready. I also should like to have your comments about the sending of eggs
and any improvement that you may suggest. For several reasons (custom examinations,
weight, inaccuracy regarding the state of development) I believe that sending eggs
in tubes is superior to sending eggs in dry or moist peat. I know that the tube
shipments will make more work for the breeder, however he knows at once how the
eggs are.
I also believe that independent of what the species is, the eggs from the tubes
should be placed in rainwater as soon as possible, and that they should stay there
with free entrance of air until pigments have developed inside eggs. The pigmented
eggs should be taken into a glass tube and transferred into "tobacco moist peat"
drop by drop, egg by egg. They should not stay in the peat for more than 4 weeks,
better 2 weeks. To help hatching, dry food (a knife point or less) should be added
to the peat before pure rainwater is poured on the peat. There should be enough
peat together with the egg as to form an unbroken layer all over the water surface,
not more than a few millimeters thick in order to support the fry when it takes in
air for its air bladder. Glass should stand in the dark and not be inspected during
the 24 hours after watering. Non-annual species and some of the annuals we will
not put into peat before hatching. If there normally is no "belly slider problem"
we will use dry food into the water and hatch the fry about one week after the
ended development of fry inside the egg.