couple ?'s about raising fry

[tonkadawg]

The wifes pair deliver a brood every two weeks (almost on the dot) and we've been making progress in our technique to raise these little guys. While not everyone makes it, we currently have 3 brood still swimming.

I've been feed the fry live rotifers that I culture for about the first 3-4 weeks and then switch them over to bbs enriched with selcon. I also picked up some frozen rotifers from the LFS but I can't tell if the fry eat this. I've also tried cyclopese but they haven't taken it. Are there any other foods I can try to feed these guys or is what I'm feeding now ok?

At what point (age/size/?) should I look at moving them into a larger tank? I raise them in the 2.5 gallon gold fish bowls, using an air stone for circulation. I have a 30 gallon set up with nothing in live stock wise, except for LR. This tank also has airstones for circulation. The idea was to move them to this 30, but I am not sure when I should do it.

Thanks for your help!

Matt

 

[chkra_hp]

you should definitely checkout seahorse.org they have a big library with article about taking care of fry.

 

[ann83]

What species?

 

[tonkadawg]

H. Erectus

I just read the articles over at seahorse.org - picked up some good ideas. I am going to try and start feeding the fry enriched bbs sooner, and overlap the feedings with the rotifers as DanU suggests.

I also am thinking of modifying the 30 setup to incorporate a sump along with HOB filter like a bio-wheel again per DanU's write up, but still up in the air on that. If I do add a sump to the 30, then I will lose the ability to keep multiple broods separate. Not sure if that matters or not?

 

[ann83]

Its better to seperate the fry on size than on age. But yes, you want the larger fry seperated from the smaller, so that the smaller still get their share of food and don't get bullied by the larger.
Do you know if you have northern or southern erectus? If you have southern, you won't need rotifers at all, and the kreisel type systems aren't necessary, as they hitch from birth. However, if you have northern, you need to treat them more like kuda or reidi fry. If you let us know where you got your horses, we can probably tell you if they are northern or southern, otherwise the size of the fry and their ability (or inability) to hitch at birth should give you an indication.

 

[tonkadawg]

ann thanks for the advice! You bring up a good point on keep the fry separate so the smaller get enough food. So with that said, I will keep my current kreisel style set up.

I don't know if I have souther or northern erectus. I got the pair from a LFS who said they were tank bred by someone locally. Is there any way to tell?

The one thing that does concern me is that my fry haven't hitched to anything. I have provided hitching posts aka plastic plants thin enough for their tails to wrap around. Maybe I have too much flow? Or maybe I don't have erectus?

heres Joe:

and heres Bella:

 

[ann83]

Southern erectus will pretty much hitch at birth. Northern erectus, kuda, reidi, and other pelagic species should be hitching by 3-4 weeks. You shouldn't have much flow in with them at all. An airline should do just fine. Too much flow will also prevent them from catching enough food. I can't tell from the second pic, but the first pic looks like Reidi to me, and not much like the erectus that I've seen. Look through the gallery on seahorse.org, there are pics of most species posted. Pay special attention to the shape of the coronet on the species. There are also threads in the discussion forums under "propagation and rearing" that will help you raise pelagic fry (kuda, reidi, northern erectus).

 

[cmsargent]

Pretty horses! Those look like reidi to me, definately not erectus. So reidi fry are pelegic and need the kreisel system for 4-6 weeks. That's about when they're start hitching.

I noticed you're in Springfield. I work down there. Just curious what LFS these guys came from?

I haven't raised reidi but I'm currently working on some N. erectus broods. Give me a PM if you some advice on what I've learned.

One thing you might try if to get them on the small strain brine. They should be able to take them earlier than the regular strain. Also have you tried any live copepods? Are you keeping them in greenwater?

 

[tonkadawg]

after looking around, talking to the wife and LFS, they are in fact reidi.

So knowing that, I am doing good with the kreisel style system currently up and running.

cmsargent:

I got these guys over at Marine Scene a little over a year ago.

I'd love for you to share any advice you can offer.

I'll have to snap some shots of my set up, but until then...

Tanks are the 2.5 gallon fish bowls with airstones. Per ann's advice and what I've read, I cut back on the flow last night.

I don't keep the fry in greenwater, but I do have two cultures of rotifers going. I do a daily water change and once the tanks have been cleaned and the fry are back, I add about 1/4 volume of the rotifers to the fry tank. I also add some DTs. So maybe in a way I do keep them in greenwater. I feed the rotifers for the first 3-4 weeks.

Once around 3-4 weeks, I start to add cyclopese and also freshly hatched, enriched San Fran strain bbs. I also decap the cysts prior to hatching.

I feed 2-3 times a day. In the morning, I add either rotifers or bbs/cyclopese or both. Then when I get home, I stop the flow and add more food. After about 45-60 minutes, I perform the water change and start the flow back up. Then about an hour before bed (appx 4 hours from the water change) I again add either rotifers or bbs.

I do have one more question, I read on another board that if the fry are 'twitching' or it looks like they are scratching with their tails, there is probably some sort of parasite attacking them which will eventually lead to death of the fry. All of my fry do this, but I always thought is was just from the live rotifers or bbs annoying them (sorta like a fly can annoy me). I can't find the info I was reading before and am now afraid it's not the live food causing the twitch. Can anyone shed some light on this?

(edit)
wow - long and rambling post - sorry!

 

[ann83]

It can be the bbs or the rotifers annoying them, it can also be parasites, but more likely it is ammonia in the water. I'd add some Amquel Plus to the water maybe once a day to keep ammonia levels down when you aren't doing a water change.
And, keep an eye out for hydroids.
Also, I'd switch them over to the bbs sooner, keeping them on rots for 3-4 weeks could be part of your fry raising issue too. Rots aren't good nutritionally. If you use small strain bbs (I believe SFBay might be smal strain), you should be able to switch them over after the first week, and some may even take small strain bbs from birth.

 

[tonkadawg]

sounds good ann, I'll pick up some amquel to add, probably in the morning, since the water changes are in the afternoon. I am coming up on 1 week with my latest brood, I'll go ahead and try bbs (San Fran Bay) around then.

Thanks again for all the help and advice!