Hoplo Question

[khall]

Hey guys!

I have two Megalechis thoracatas since last december. Sadly since on the internet there is next to nothing about hoplos, I had to find out most things by myself.
They were fairly small when I bought them, about the size of a neon. They've grown big however, one of them is about 11-12 cm already if not bigger.

And here lies the problem. They live in a community aquarium with other, relatively small fish. Two corydoras nanus, 6 neons, and 2 adult marble mollies. One of which gave birth to a bunch of fry three days ago. You may see where I'm going with this, but hang on.
Now, I've raised not one but two batches of guppy fry to complete adults over time in this tank, and the hoplos have never laid a finger them. So you can imagine my total surprise when I discovered that they desperately want to eat the young mollies. The attacks only happen when it's twilight or dark, so I'm letting the light on during the night. It works, for now.

I couldn't help but notice however, that they've definitely begun "eyeing" the neons and the corys as well. Am I imagining things, or will they try to eat them as well? They do not fit in their mouth just yet, but the hoplos do grow alarmingly fast.
What should I do? I feed them well every day, I just don't get it why would they want to eat their tankmates in addition to all that food.

 

[ShinySideUp]

What should I do? I feed them well every day, I just don't get it why would they want to eat their tankmates in addition to all that food.

Because it's what they do, hungry or not.

See 'Feeding' and 'Aquarium Compatibility' in this link Hoplo

 

[N0body Of The Goat]

Your story ties in with what I read about Hoplos on PlanetCatfish, they will eye up small tankmates (at least fry) as live lunch, but this is the first post where someone has wriiten something that matches the site's (often very accurate) profile.

At 12cm, they will be fully growth if they truely are Megalechis thoracata, but there are a few Hoplo-esque catfish including Callichthys callichthys that can reach ~18cm. Uploading a good photo could help reassure you of their identification. They eat like pigs, my four are probably close to fully grown now having bought them a year ago as 5cm youngsters, they are great at mopping up leftover food, but at the same time they can be too boisterous at feeding time for some fish.

You have your own dilemma... Do you want to try and save fry in a hang on breedingg net, or let nature take its course and see if any grow quick enough while evading the Hoplos. I recently made a bad call on when I thought two of my female Ilyodon xantusi were going to give birth, the 20-30 fry were instant live lunch to my teenage Lionhead Cichlids and I felt rather guilty (despite struggling to find homes for them besides the 13 that "JDs4me" now has down the road in Portsmouth, expecting their own first babies anytime).

 

[khall]

I made some pictures just now,but I'm fairly certain they are Megalechis. I've tried the breeding net option when the mollies were 1 day old. But I've noticed in the morning that a lot of them gone missing while I was sleeping. I'm guessing the hoplos spent the night siphoning the fry out and munching on them. So I was out of options, and the 24h lighting seemed to work.
Yesterday I had a better idea though, and I set a small desktop lamp next to the tank,and with it I made one corner safe for the fry while the rest of the tank is dark.

These are the two hoplos I was talking about. One is bigger, and somewhat older than the other, and definitely male because of the pectoral fin that is orange-ish and thick. He is gorgeous and very friendly. If he sees me, either he puts on a show by dancing and swimming up close, or lays down next to the glass and keeps watching me, which is a rather strange experience since I'm supposed to be watching him not the other way around.
The "smaller" one is really shy, light colored and I haven't been able to identify its gender. Perhaps male, because sometimes they're bickering.

I think they'll both grow a lot more, because in June I finally got to see an older specimen. It was huge! Must have been at least 15-6 cm, and it was quite fat as well.

 

[tribalbrit]

I have 14 Hoplo's ranging form 2" to 7". they don't seem to bother other fish and I to have raised guppies in the tank without incident.
May be you should add a few more as they do like to shoal, also add some floating plants to protect the fry and may be start to feed them just before lights out.
One of the best fish IMO.