Courtesy of

ARK - Arizona Rivulin Keepers

The Scheel Letters, No. 15

About 6 weeks ago I noticed an almost black young fish swimming around in a dirty tank with a mixture of various young killies. His fins were severely bitten and he fought badly with every male he came across. Certainly I was not able to find out what species he belonged to, so I lifted him out and placed him in a tank with some young "schoutedeni". Here he soon recovered but still I was in doubt where to place him. I thought it could be the "dark" type of Pterolebias longipinnis which I never saw, and such a fish might have come out of the "longipinnis" in eggs with Dr. Foersch sent me. More and more this male turned out to be a fish close to Cynolebias, something like a mixture of "nigripinnis" and "whitei". He is as dark as my males of "nigripinnis" but the shape is typically "whitei". He could not possibly be a hybrid between these two species, as I did not start the crossings in Cynolebias so early that he might come from these crossings which however until now have only given transparent eggs, also in the many eggs spawned with "nigripinnis" male and "whitei" female. So possibly this male is a "black type" of "whitei". He is not almost black, the pectorals are not completely black, but the body color is as black as it could be. He behaves as a typical Cynolebias in spawning with female "whitei". About 50 apparently fertile eggs have already been collected.

I am very interested to have information on "something like that" in other stocks of "whitei".

Perhaps you have been waiting for eggs of "whitei", also I must confess that I have been a little late, but now 2 males (normal) and 4 females are working for you, so no doubt the eggs soon will come. Most eggs will show the dark pigmentation of an embryo after 4 weeks on shallow water, so then it is time to dry up for 2-3 weeks or more. "whitei" is a very handsome fish and very popular here (it is also called Pterolebias elegans, also it has some traits pointing against this genus).

Egg Structure in two Species of Pterolebias

The surface pattern of eggs "longipinnis" is not the same as in "peruensis". Eggs of "longipinnis" have minute dots rather evenly distributed all over the surface, whereas eggs of "peruensis" have very large dots, also evenly distributed. Only a look in the microscope will show you what species you have in front. But both species spawn eggs of the same (big) size. Also look at the newly hatched fry of these two species, notice their very big pectorals and the shining eyes.

A Variation in Pterolebias peruensis

One of the about 30 adult males which I raised in Pterolebias peruensis shows one big black dot just behind his pectorals. This dot has no edges with red and its borders are somewhat blurred. The eye and gill covers in this male is much more golden than in the other males of the same size. His eye is golden, not brilliant green as commonly in males "peruensis". This male will be used in future breedings of this species in order to see if these traits are inherited to the offspring in first or second generation.