Spawning c121

[rhibear]

I was hoping that someone here might have some tips for me.
I managed to get 7 c121s a few months ago, they turned out to be 5 females and just 2 males. I've been feeding them live black worms, frozen blood worms and daphnia plus crushed high protein pellet foods. The females look ready to pop.



They are housed in a 75g planted display tank with a couple of different plecos and my black schultzei colony that spawn quite regularly. They have been getting twice weekly water changes of about 40% which drops the temp from 76F to around 72F.
Our well water chemistry is:
6.4pH - Amm & Nitrite:0 - Nitrate:5 - Gh:< 1 - Kh:< 1
the tank water is the same, with occassionally higher nitrates up to around 20 before a change.
After a cold water change they look dejected and miserable. When the schultzei spawn the c121s sit in their corner and appear to quietly wait it out. Occasionally I see a male slowly following a female and flirting with his whiskers. They seem active, happy and healthy, but there has been 0 spawning activity. Any suggestions welcomed and appreciated.

[MatsP]

These fish come from the Upper Rio Negro. I would push the temperature a tad higher, perhaps 82-85'F. Then drop the temperature by about 5'F when doing the water change.

This is not a guaranteed way to do it, but I think they may look less "listless and dejected" after water change if the temperature is a bit warmer.

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Mats

[Coryman]

I would be inclined to reduce the high protein foods, although a female I think the fish shown is somewhat over weight. This can be clearly seen with the bulging below the head. I would at giving them a more balanced diet will far less protein.

And as Mats has suggested raising the temperature to at least 80ºF would help.

Ian

[rhibear]

Thanks for the suggestions.
I agree that they are overweight, largely because they have been hogging down the food intended for the black corys who had lost some weight. I will try to balance their diet better.
Regarding the higher temps, I am confused as to why the temp range on the Burgessi Cat-eLog page is only 73.4-78.8°F if they prefer higher.

[MatsP]

Because we're not perfect here at Planet Catfish, and other people are not perfect... 22-26'C is a generally good temperature for Corys, so it has been applied here and on other sites pretty generously...

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Mats