Cory Body Language Differences

[Deleted member 149562]

@GaryE

Aquarium & food.....nothing remotely special, different food mix each day.



The UV is something I have always used. Currently a 24w GKM. The aquarium is a 200 litre/53 US gallon with air curtain at the rear, RGB MCR lighting and a basic Aquael double canned Turbo 2000 internal filter.

Nothing special at all...and fake plants, mangrove root and rock hides too.

 

[Byron]

I'm considering that, maybe have a beach at one end, and slowly change it over to 100% sand. They seem to do ok with the round gravel with no obvious barbel erosion or other injury (they love to graze the substrate), but I would like to have a proper environment.

There are more significant issues with gravel than just the grain roughness/angularity. Corydoras are filter feeders, and they can only do this with sand. That means the areas of larger-grain gravel will not be turned over by the cories, and any bits of food get down and stuck. This causes bacterial problems for substrate fish especially, but is also an issue in general for an aquarium. The waste control bacteria have more difficulty dealing with this than they do in sand. Barbel problems are probably more frequently due to the bacterial issue with larger grain size than to actual roughness. Pea gravel for example is in my experience very smooth, but the bacterial problems will cause barbel erosion nonetheless.

Changing the entire substrate to a non-angular sand is recommended if cories or similar fish (loaches) are present. A uniform substrate material also looks more natural, and visually gives the tank more space. As soon as there are two or more substrate materials, the floor of the tank appears smaller.

It is also not advisable to change the substrate in stages, but remove the fish and do it at one go. Hitting a dead spot can be fatal, as another member some months back reported when doing this.

 

[Lynnzer]

I have a Julii and a Striata left over from a tank disaster a good time ago. Previously there were two Julii in one tank that I kept to keep the bottom clean, and then I got a couple of Striata. From the very 1st stocking of both species, one of the Julii was absolutely head over heels with a Striata. I mean absolutely devoted.
I guessed that both the Julii were male so didn't quite click sexually, and that at least one of the Striata was female.
After my tank disaster, the ones left were those that had become inseparable. I even bought a couple more Julii and put all of them into a smaller separate tank, but there was never any mating behaviour or even any noticeable closeness by the older fish to the new ones.

Felling a bit of a sourgrape, I decided to put the unlikely couple back together again and they are as happy as ever. Mating behaviour seems to be happening but there's been no noticeable egg laying. I suppose that fertilisation wouldn't happen cross species anyway.
That apart, just watching their antics is so engrossing. I must get a short video clip to put on here.

 

[Byron]

I have a Julii and a Striata left over from a tank disaster a good time ago. Previously there were two Julii in one tank that I kept to keep the bottom clean, and then I got a couple of Striata. From the very 1st stocking of both species, one of the Julii was absolutely head over heels with a Striata. I mean absolutely devoted.
I guessed that both the Julii were male so didn't quite click sexually, and that at least one of the Striata was female.
After my tank disaster, the ones left were those that had become inseparable. I even bought a couple more Julii and put all of them into a smaller separate tank, but there was never any mating behaviour or even any noticeable closeness by the older fish to the new ones.

Felling a bit of a sourgrape, I decided to put the unlikely couple back together again and they are as happy as ever. Mating behaviour seems to be happening but there's been no noticeable egg laying. I suppose that fertilisation wouldn't happen cross species anyway.
That apart, just watching their antics is so engrossing. I must get a short video clip to put on here.

Do you perhaps mean Corydoras sterbai, rather than C. striata? There is no cory species "striata."

Hybridization is certainly possible with species within the same lineage. This can be a problem.

 

[Lynnzer]

Do you perhaps mean Corydoras sterbai, rather than C. striata? There is no cory species "striata."

Hybridization is certainly possible with species within the same lineage. This can be a problem.

Yeah, Sterbai. Actually I do have Striata Loach too.
Hybridisation would most probably have happened already if they were a male/female. Might just be the two of them are horny males.