ARK - Arizona Rivulin Keepers

The Scheel Letters, No. 29

Nothobranchius:
"palmquisti male/rachovi female": 26 Sep. 59 first batch of eggs was collected. They caught fungus, most of them, but until 31 Dec. 59 I had some (4) transparent eggs which did not show any trace of an embryo. After changing water, they "burst". Another spawning that ended 29 Oct. 59 gave also many fungused eggs, but still I keep 11 of these eggs. 06 Jan. 60: no trace of an embryo in any egg. In a few eggs the yolk ball is not regularly shaped (decomposing?).

"rachovi male/guntheri female": eggs on shallow water, with air entrance since 26 Sep. 59. 06 Jan. 60 no trace of an embryo in any of 31 transparent eggs left. See also before about crossings inside Nothobranchius.

Rivulus:
in order to "test" the interesting Golden Tail Rivulus (in Germany called Rivulus spec. DATZ Mar. 59, page 75) I got a pair of R. cylindraceus from a friend and 05 Sep. 59 I was lucky to have several eggs in both possible crosses.

"cylindraceus male/golden tail female": 34 eggs within a few hours. 12 Sep. only 13 are left. 5 of these had a small embryo (200 degrees on yolk ball), rather fine blood system, also rather heavy pigmentation. 2 eggs had a smaller embryo. 5 eggs had no trace of embryo, but still the yolk ball is round and clearly separated from the "white". 29 Sep. 59: 1 big fry with big yolk sack did hatch "by itself". 30 Sep. 59: another 2 fry hatched. As I was about to go away for holidays, I put these 3 fry into a bare tank. I have not seen them later on.

"golden tail male/cylindraceus female": 28 normal eggs (plus a small one). 12 Sep. 59: only 3 eggs left. 1 egg has some trace of an embryo. 2 eggs have none. No pigments, embryo is only 30-40 degrees on yolk ball. This will not work and in a few days the eggs died. I will try again later on. The first cross may work possibly.

Aphyosemion: (continued from the pages before)

"cognatum male/schoutedeni female": from 01 June 59: the fry (11) turned out to be 11 strong females. In Oct.-Nov. some looked like "cognatum" somewhat, but now they are not to be distinguished from females "schoutedeni". These females are fertile. They spawn lots of eggs in p.i. backcross to "cognatum" and "schoutedeni" males. Eggs of this back cross develop, but still they are only a few days old.

"schoutedeni male/calliurum female": of 17 May 59 turned out to be a handsome pair. They suffered from Oodinium and were about to die around the maturity, but later on they both recovered and now they seem to be very hard fish. Male is mostly "schoutedeni", but it differs from the father fish in a more brilliant and more greenish body color, a greater dorsal fin and in having about double the amount of red dots on the sides. Dots are in irregular rows. I tried it with the "cog/schout" females (2) and had more than 50 eggs. All of these turned out to be sterile. So possibly it is sterile as the male hybrids produced in 1958. Female has not been tried yet, but she is very promising. Only to see if the cross "schoutedeni male/cognatum female" which I forgot to make this summer works I had 15 eggs spawned on 25 Aug. 59: on 18-19 Sep. 59 I hatched 3 plus 3 fry that were normal. So also this cross may be made. Hatching fry by "dry food".

Epiplatys:

The only result in 1959 was one male "sexfasciatus male/chaperi female". It is about 45 mm and not at all handsome. Still the formation of the cross bars seems to be very difficult for him. Mostly there is a trace of a dark bar behind the gill covers and the same trace near the caudal base, but just now the pigments seem to concentrate mostly near the central line from the gill cover to the caudal base like a diffuse longitudinal band, poor male, also he is not very strong. No red on the lower jaw. No black line below in the caudal fin.