Corydoras concolor, breeding tank

This is an old favourite of mine.

The tank is not designed for maximum production of Corydoras eggs but rather to be functional and nice to look at, at the same time. I think it's a very good example of how a breeding tank does not have to be bland and boring.

The 72 litre tank runs by a single powerhead with an attached sponge and a 50w Eheim heater. The heater might be the only thing I would have changed if I was reworking this tank. A less visible location would have made the tank look even better.

These are wild caught Corydoras concolor and it took some time before the first spawn occurred but after that the fish spawned regularly usually after water changes had been performed.

The fish are kept at around 24 degrees Celsius, pH of 6.5 and in very soft water. The interior of twigs, plants and moss, especially at higher locations provide perfect spawning material for these fish.

In this tank I do nothing when it comes to rearing the eggs/fry as I am happy with a few young additions to the group. Fry survival could however easily be increased by providing additional hiding spots for the fry such as clay piper, moss etc.. The fishkeeper could also easily remove the spawning material after each spawn and choose to rear the young in a separate tank.
 
Again this is not something for the fishkeeper that wants to produce large amounts of young but it's suitable for people that want to watch breeding behaviour in a nice setting.

I am also of the opinion that this kind of tank lead to quality fry as the young has to compete for food and survive on their own which naturally culls the weak.

Happy Fishkeeping!

 

Oak Leaves

Todays crop: a box of dryed oak leaves

Dead leaves are beneficial to the home aquaria in many ways. I'm using oak leaves myself and as this is the season to be picking them I thought I would write a quick post about them.

Why Leaves

The benefit of using leaves in the aquaria are many and there is plenty information available on this subject, I will shorty highlight some of them below.
Looks
Many of our aquarium fishes come from habitats littered with leaves. Heiko Bleher himself mentioned how he knew that he would find Apistogramma species in a leaf litter habitat (MaxiZoo talk, Dublin 2013). Oak leaves are a great way for any aquarist that wants to try to replicate such a habitat and it does usually look great.
Biotope/breeding
Tannins released from the leaves helps lowering the pH and stain the water to a tea-color. This further replicates the habitats of many blackwater species. Replicating the natural habitat in this way will significantly increase any breeding attempts.

Hiding

Leaf litter provides an abundance of hiding spots for fry and adult fish alike which adds to the general wellbeing of the fish. In a breeding tank leaves can be the difference between a good survival rate of fry or an unsuccessful attempt.

Food source

The leaves are also beneficial to the growth of fry as they provide an environment for microorganisms on which many fry feed. I often use oak leaves in my rearing tanks and lately a batch of Hypancistrus debilittera were grazing eagerly on the leaves, the batch grew very well and I contribute part of that to the constant availability of food, deriving from the leaves.

Preparation

I have only used oak leaves and can only comment on them.
Collection
Pick clearly dead/dry leaves of a species you know is aquarium safe. Pick only leaves that have already fallen to the ground. Avoid leaves from a polluted area, rotting, exhibit fungi growth or anything else you are not sure about.
Storage
Store the leaves in a dry area, I use an open card box for this purpose. Do not store them in plastic bags or sealed container until you are certain that they are completely dried out. Pick out any “bad” leaves prior to use. I usually dry the leaves for at least a month before use.

Use

Adding leaves
Add the leaves gradually, you will get familiar with how much leaves you need and how they affect the color of the water. The leaves will decompose over time, you can either leave them as they are or if you are afraid of leaf matter clogging the filter/spoiling the looks; siphon the smaller pieces out while performing a water change. Just make sure that you don’t siphon out your fry, in a set up with leaf litters fry can often go unnoticed from view.

Fish species
The effect the leaves have on the water makes them suitable for blackwater species. Personally I use oak leaves in tanks with species of Ancistrus, Corydoras, Hara, Peckoltia, Pelvicachromis and various tetras. Make however sure of what conditions the particular species you keep needs before planning the tank.

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.