as promised
About the breeding of gastromyzon few facts are known. That’s why the following summary of observations made earlier are still of importance.
The articles about the breeding of gastromyzon by Philipp Dickmann have been published in „Das Aquarium-Magazin“ in 2001. As the magazine doesn’t exist any more, I’m happy that the publisher of the „online aquariun-magazin" has let me the articles. thanks a lot.
The author presents two species: gastromyzon punctulatus and monticola., which are scitulus (as far I can judge by the pictures) and auronigrus (confirmation by H.H. Tan). The confusion is due to the fact that before the revision by H.H. Tan in 2006 correct identification was just luck.
First part
Gastromyzon scitulus: the author collected them in february/march 1992. no specimen smaller than 1 cm were found.
A big problem was the sexual dimorphism: mesures were taken and put into charts. Drawings show the differences. all observations are confirmed by the facts in "The Borneos Suckers"!
A pair was placed in a 30 lt tank, together with two halfs of a flowerpot, three boulders and some swimming plants; strong aeration, no filtering system.
Good feeding with living and frosted mosquito larvae etc in the next months.
The temperature was raised to 28° during a period of 8 weeks and maintained for about 3 weeks. Then the temperature went up to 32° accidentely. During this peroid feeding was intensivated.
After a first mating a water change with 20° was made to cool down to 25°. In combination with a low pressure active front the spawning began.
At least 100 eggs were released, smaller than 1 mm, waxy, solid, clear, glaced over in the middle and sinking to the ground; later becoming whitish.
The adults were taken out of the tank.
After three days the hatching begun, the fry was about 3 mm long, glaced and very thin; dark pigmentation on the end of head and caudal fin base. They were photophobic.
After three days, infusoria were given as artemia were to big.
All got lost after 3 weeks due to rotten plants.
The spawning is shown with exellent drawings: a sort of „show-swimming“ forming an eight by the male; clinging together with lateral interlocked bodies; swimming up to a vertical suface and releasing eggs and sperm. After that the female had a whitish secretion at the sides. The adults were „not much“ after the eggs.
Conclusion: gastromyzon are free spawners with sinking eggs, which didn’t stick much.
I hope to have given some new ideas or at least the confirmation to be on the right path.
second part in a while
cheers charles
