Breeding Corydoras parallelus Burgess, 1993
The first time I saw this Cory was in Werner Seuss´ book “Corydoras” (Seuss 1993). This clear stripe pattern and the golden spot in the neck were looking very attractive. But this species seemed to be unavailable. C. parallelus has been known since the mid1980’s, but this species is caught only very occasionally at the upper Rio Negro (the exact location is unknown). Most of them are exported to Japan (Evers 2005).
So it was a very special moment when I heard from Hans Evers that he was able to obtain a few parallelus and had a small breed from them. I´m sorry Hans, but I phoned him several times to hear how they are growing and finally I was able to obtain six of them. This was a dream coming true.
I received four males and two females in a size of about 3 cm, a bit more than half a year old and in best condition. They moved into a 60x30x30 cm Tank with a sponge mat filter, air driven waterpump and gravel/sand bottom. The tank was furnished with some Java moss, a piece of driftwood and a small clump of Anubias nana.
They received best food, based on Grindal worms (Enchytraeus buchholzi), frozen bloodworms and Tubifex. With this diet they were growing rapidly and put another cm on their lenght. I made occasional waterchanges, but only very slighty. When autumn was coming I increased the frequency of waterchanges, but to be honest, I didn´t believe that they ewere able to breed in this size. But I felt that it was bettere to bring them in seasonality.
In late December I found them spawning! It was only a few eggs, most of them were not fertile, but those eggs are really big! The biggest I´ve ever seen, about 3 mm in diameter. The eggs are very soft after they are laid and it is better to leave them for an hour at their place before collecting them. They are very sticky and sometimes it is difficult to get them off the finger.
From this first and only spawn in this season I obtained six fry. Not too bad! I was very much looking forward to the next year.
Winter 2006/2007 was my parallelus-year. The adults had grown up to a size of about 5 cm. The males more slender and a little bit smaller than the females. After a summer in a community tank with low food amounts and few waterchanges they moved in the same tank as in the year before and received the same nutrititious food.
It needed only two weeks to see the females becoming round, with a big fat belly. Full of eggs! I started waterchanges of 30 – 40% with cool rainwater at the beginning once pere week, latere twice per week. And they started spawning!
The spawning behaviour was different to Evers´ description (Evers 2005) although his specimens are the parents of my specimens. While they made one large spawn in Evers´ case, in my case after a bigger initial spawn (about 50 eggs) they spawned regularly every week with 20-30 eggs per week. The eggs are deposited single, most of them were to find where the Javamoss adheres to the glass.
All eggs are transferred to small plastic shells with aquarium water, added one drop of esha 2000 per litre. There is a air line in every shell, bubbling very slow.
After three days they hatched. According to the egg size, the larvae are very long (5 mm) with a big yolk sac. It took about another 3 days until they had resorbed the yolk sac and became free swimming. At this time I gave the first food (Microworms, Panagrellus redivivus). I prefer this food because it is sinking to the ground immediately – other than Artemia nauplii.
After a few hours it is easy to see if they have eaten. The belly is bigger and in case of microworms white. If they haven´t eaten, it is too early – make a waterchange and try again next day.
After about a week in the shell and growing a bit – showing already some body pattern – they can be transferred to a small tank.
Literature:
Evers (2005): Ein Traum wurde wahr: die Nachzucht des Parallelstreifen-Panzerwelses. Amazonas 1, 44 - 51
Seuss (1997): Die faszinierende Welt der Corydoras. Landbuch-Verlag, ISBN 378420557-7
