Breeding Report Corydoras concolor, Slate Cory

This is one of my absolute favorites and a much underrated species. The fish available in the shops are often juveniles that are not that impressive to look at, mainly due to their greyish coulour.
This drastically changes as the animals mature and adults are among the most impressive Corydoras there is.

Like with most Corydoras the females grow rounder than the males, this is however a very robust species in general so even the males have a heavy look to them. Both sexes grow an extended dorsal fin but the dorsal fin of the males grew to a very impressive length.

I acquired these fish in May 2013 from Artane Aquatics as wild caught juveniles, I also later added a few individuals from a second supplier.

The fish were kept in a 60x40x30cm grow out tank with fine sand, plenty of twigs and moss. An air driven sponge filter as well as a sponge filter driven by a power head was used, the current was in places of medium strength.

The diet consisted of live foods such as mosquito larva and white worms but also dry foods such as catfish pellets and flakes, the fish grew very well.

Weekly water changes using slightly colder water were made of about 20% of the total volume, this might have triggered the intitial spawn. It should also be noted that breeding activity intensified as live foods were offered on a regular basis.
  
The first spawning took place nearly exactly a year after the purchase, the reading were as follows:

Temp: 24-25°C
pH: 7
Hardness: 30-40 ppm

The fish scatter their eggs and they can either be collected and raised in a breeding box or left in with the parents as quite a few seem to survive in their presence.

For the first spawns I collected the eggs and raised the young using fine flakes, brine shrimp, micro worms and mosquito larva. After the initial spawn the adults continued to breed on a regular basis and I stopped collecting eggs. There were still quite a few survivors appearing now and then.

I personally try to keep plenty of moss and dried oak leaves with my fry as these provide both shelter and micro organisms for fry to feed on.

The group was later moved to a community setting containing guppies, tetras and also other bottom dwellers such as Hypancistrus and Ancistrus species. Even in this setting there were juvenile Corydoras concolor appearing on a regular basis.

Notes on breeding Hypancistrus debilittera, L129

There are three positive sides which made me decide on this species; it’s small, beautiful and relatively affordable compared to many other L-numbers. Its small size makes it easy to keep a decent sized group. The males have showed very little aggression so far which also helps.

The group was bought from Seahorse Aquariums in the beginning of June 2013 and consists of two males and three females. The individuals were wild caught young adults in good condition which made it easy to sex them by viewing them from above. The males had a distinct V-shape and showed “hairy” odontodal growth along the lower body, the females were quite plump in comparison. I have been wrong many times when sexing plecos but these were quite easy (or I got lucky).

The group reside in my 125 litre corner tank along with 12 Ember Tetras and some Otocinclus cocama.
The tank is filtered by a small air driven sponge filter as well as a 600 L/H powerhead with a large sponge, the powerhead creates a moderate currents which flows along the front glass of the tank.

Readings:
Temp 26°C
pH 6-6.5
German hardness °dH 3

Wood and roots comprise the furniture as well as six small sized (often used for L046) breeding caves plus a few coconuts.
The dominant male chose a cave near the front of the tank with the entrance exposed to the current. Strangely the second male never settled in one particular cave. The females seem to prefer roots and coconut shells as temporary hiding spots.

Four spawns have taken place so far with a few weeks in between each. It looks like the females take turns to mate with the dominant male. The male has only guarded one clutch at a time compared to for instance common Ancistrus where the male can guard clutches from several females at the same time.

This is the point where I started to have problems. The tank is not a dedicated breeding tank hidden away from disturbance, its placed in the living room. Any disturbance such as a water change or a lot of movement in the room has triggered the male to eat the larva and fortunately in the process “fanning out” some of them that could be rescued.

The last time I witnessed the event it was extremely frustrating watching dead larva with their yolk sacks eaten being flushed out from the cave. The cluthes seems quite small, I'm not sure exactly but it seems that the egg count have been around 10-15 max, maybe less.

Both Darren and Bart from www.irishfishkeepers.com have advised to cover the tank and this would probably work. I would however prefer to find another solution as the tank was supposed to be a “display tank”. Before going down this route I will cover up the males cave with roots and hope that this will make him feel a bit more secure and obscure his line of sight from movement in the room. The male is also young (possibly first spawns) and he might get more comfortable in time.

Not all was lost though as I have managed to catch some of the newly hatched larva that were flushed out. These were raised without problems in the floating breeding trap above, they grew fast and at a length of about 2cm TL they were released back into the tank to fend for themselves. The breeding trap was cleaned once per day; the sides were gently brushed with a tooth brush and uneaten food was removed with a turkey baster. The fry were fed twice per day with a variation of dry foods. The box also contained oak leafs which the fry seemed to feed greedily from. Fresh water from the main tank was flushed into the box trough a small air-lift sponge filter. I let few snails reside in the breeder box as a clean up crew for any uneaten food that i might have missed.

I’ll update this post if there is any news on the nervous male, he is at the moment guarding a new batch so fingers crossed.

Update 1:

 I just fished out these little lads from their parent’s tank. They are from one of my first spawns of Hypancistrus debilittera, L129 and I believe that I managed to catch roughly two thirds from that batch.

It is very important for the growth and well-being of young plecos that they are not kept in too crowded conditions. Even more so when several batches share the tank as the smaller ones will have a very tough time competing for food and hiding spots against their larger siblings. 

These fish were moved so that their younger siblings can get a chance to grow properly and become strong little fishes.They have now moved to a 72 litre tank with strong filtration and plenty of hiding spots.




Update 2:
After the spawns described above the male calmed down and started to raise the fry himself, no further intervention was needed and the fish now spawn regularly once per month.

Very small/young Bristlenose father

The picture above shows a common Ancistrus male, he is about 5-6 cm in total length and between 5-6 months old. The cave is approx 4 cm wide.

This male is guarding it's first batch of eggs and the mother was an large adult female.

The male seems to have developed really early and already have a full set of bristles with split end.
There were no adult males in the tank as I did not intend to breed the female, this could have lead to that this little lad got his chance.

Even though this male developed very fast it is proof of just how productive this species is when it comes to breeding.

From now on I will have to separate the young males from the girls much earlier than i have been doing so far.

Melander

Corydoras schultzei black, first spawn!

I had a pleasant surprise today, my group of Corydoras schultzei "black form" spawned for the first time.

The group consists of two males and two females, approximately 12 months old, however only one female participated this time.

I was so delighted when I saw it and completely forgot to take pictures of the eggs, too busy collecting them I suppose.

There was no other trigger than weekly 20% water changes and regular feeding of catfish pellets, waffers and blood worms. In fact I had actually not done this week’s water changes yet. A possible trigger could have been the C. panda’s regular breeding behaviour.

Having these two species breeding in the same tank is slightly worrying as the last thing i want is hybrids. As I was monitoring the spawning today there was no interaction between the two species but I do need to move the C. schultzei group to their own tank.

Two males and one female took part in the typical cory T-position and the eggs were scattered on the front glass of the tank, right in the current of a wavemaker.

The egg count seems to be somewhere between 40 and 50, sadly at first glance many seem to be infertile but I hope the ratio will improve as the fish gain experience. They are now being kept in a breeding net in the same tank as the parents, hopefully everything will go well and there will be a positive update soon.


Readings:
Temperature: 24.5 °C
pH: 7