Can you ID my little corydoras please?

[Miss-Pepper]

Hi, I had what I thought were four peppered corydoras but a month has past and the smallest has hardly grown. The others are growing up, looking nice and fat and just like peppered corydoras. They also swim about a lot as a 3, while the smallest one does his own thing. They sometimes follow him but he doesn't seem to want to join in. Is he just small and sickly? He does eat, but he does prefer frozen or live food, he's also pretty good at getting the flakes off the surface but his mouth seems too small for the shrimp pellets I put in for the others.

Link to video (I couldn't get a decent picture, so he's the smallest, paler looking one that I'm trying to focus on):

I stumbled upon the type, Corydoras cochui and wondered if he was one of these instead? I just bought him from the LFS in a mixed tank, so he could have been a rogue one left over! It was hard to notice any difference when they were small, but he's always been the smallest.

Water readings: 0 ammonia, 0 nitrite, 5ppm nitrate, 6.8pH in a 25 liter tank with 6 neon tetras and some plants. They're moving into my community 180 liter when it's ready, but they're no more than 1 1/2 inches at the moment.

[The.Dark.One]

Hi
I think it is a peppered but is, how can put it nicely, a bit of a runt. cochui are hard to obtain and it isn't one of those IMO. Just looks like a peppered that has not developed properly (he has a slight kink to his back end too). Still a nice fish to keep though.

[Miss-Pepper]

Thanks for your reply. Poor little fellow, at least I don't have to hunt down more for friends! Will he ever grow up, or is he doomed to forever be like this?

[The.Dark.One]

It will probably grow, but perhaps slower than the others and may remain stunted.

[Miss-Pepper]

Well, there is hope for him at least! Good to hear

[corylady]

heres another thot. i breed trilineatus and orange lasers. the lasers r new; the triple-lines i've been doing 3 1/2 yrs. raised and sold, gave away,traded a lot of fish. in my teenage tank i have 150 juvies.my girlfriend and i were looking at them and spotted what she calls a "sport". he is solid dark walnut brown as compared to the black and silver triple-lines. i'v had him looked at by lots of knowledgeable people and the popular concencus is he has a recessive gene. he has his own 10 gal w/some buddies to grow up to be a spawning group. breed back dark siblings to dark siblings(Obviously this will take awhile!). could u have something different? u never know. he looks healthy enuf but maybe just a runt. my recessive gne fish is not growing fast as his buddies and was told to feed him lots of protein, such as more baby brine. i like the more silver in the pepper in him.

[Miss-Pepper]

Thanks for another idea there corylady. Since moving all my corys to the big 180L tank they've all grown up...especially the 'runt'! SHE is now the largest, fattest cory in the tank - I've seen her spawn and lay eggs ( and then eat them ) but she remains a lot paler/silvery than the others. Shame she refuses to leave her own eggs alone. She definately has her own look and it's very easy to recognise her, I'll try and get a picture of her at some point.