Calvus Spawn

[zendog]

I have a group of 7 Calvus that are between 2 -2.5 inches long and one in particular has been hiding in a shell and then hovering over the opening pretty much all the time. I knew this was possibly the result of a spawn, but didn't think that they would actually be spawning at this size. Just in case, I keep looking into the mouth of the shell and today I could see about a half dozen fry hanging out in the shell. At this point I've heard they are getting ready to leave the shell which with the other Calvus and the Xenotilapia in the tank means pretty certain doom.

So I'm wondering if anyone has had success rearing Calvus fry in a hang on breeder box. I have one of those large size marineland ones that cycles tank water in with an airpump, so they would still be getting tank water. My inclination is to put a little sand from the tank in the bottom of the breeder box and pick up the shell and try to pour them out into the breeder box. I guess I could do bare bottom in the breeder box, but I'd like to give them the sand to help them feel comfortable. I was also thinking of adding some hornwort as well. Good enough plan, or do I need to try to set up a small fry tank? I'm just afraid of keeping them healthy in a separate tank if it is just a few fry and I've heard they are susceptible to water changes killing them off and death from overfeeding if you don't do frequent water changes. I figure the breeder box has the benefit of concentrating them to make it easier to get them food and also using the water from the main tank.

The other thing is I'm way overdo on a water change on the tank anyway, so I'm a little worried about doing that now. Maybe if I use the breeder box I should just feed the fry and give the main tank a little fasting to try to keep the same water for another week and not shock the fry.

Any thoughts and experience is very welcome. I'd really like to keep these alive if I can.

 

[CSnyder00]

Use the breeder box and add hiding spots/hornwort if possible. That will make them feel safe and also give them some microorganisms to feed on. I think you'll do fine if you do a partial water change after they are in the breeder box and safe.

 

[chriscoli]

ask Jim guarddog5 about how he raised his. He was quite successful. Mine have done well in breeder boxes, but they seem to really need a consistent food source. I also remember a previous speaker (Anthony Tu) talk about how he raised them.....he kept them quite warm, did frequent waterchanges, and kept them well fed.

 

[zendog]

I've moved them to the breeder box and it looks like I have about 35 or so. I taped some blue paper on the bottom and added some hornwort.

Ask I have on hand is golden pearls, so I'll try feeding them the 100-200 size at least 4x per day. They look like they have a tiny bit of your sac left, so hopeful that will carry a few along until they figure out they should rest the gp.

Thanks all.

 

[zendog]

They're still alive and I don't seem to have lost many at all. Of course saying that probably just jinxed me.

People say they're hard to keep alive and mostly attribute losses to the fry not being able to handle sudden changes in water chemistry or just not getting enough food. I'm trying to do what I can to avoid either problem.

For water stability they're in the breeder box on the main tank and I do a 5 gallon water change on the 40 gallon main tank every other day and use an airline tube to syphon the new water from the bucket into the tank so any change is very gradual in the tank and even more so in the breeder box.

For feeding I read about people having more success with a "dirty" tank than one that is pristine because it gives them something to pick on, so I've only cleaned out the mulm once from the breeder box and I see them picking through it often. I feel more comfortable doing that with the breeder box being on the main tank instead of a small tank that could go bad quickly. For food they've just been getting golden pearls, but I tried some crushed earth worm flake today and they seemed to be able to eat that as well now. I feed 4 times a day to make sure they don't go to long without food.

I'm keeping my fingers crossed.

 

[CSnyder00]

They look great! Keep feeding often. Putting a plant in there or something that they can hide in would help.

 

[chriscoli]

Fantastic! Once they start to look like miniature versions of the adults, you should be over the worst of it. My losses on comps (not caluvs) were minimal after that (barring my own stupidity). Keep us posted!

 

[mchambers]

On the mulm, Hans-Georg Evers said Saturday that he feeds corydoras fry by squeezing a sponge filter into their rearing container. Might be worth trying with other fry, like calvus.

 

[QuarterMiler]

Nice. Good luck with the rearing!
Interesting comments on keeping the bottom more "dirty". I remember reading just the opposite somewhere, the reason being that pollutants will be heavier and favor the bottom, where calvus fry tend to spend a lot of their time in the early stages. I kept my tank more on the clean side, when I grew out about 85 white calvus fry. Once they hit about a 1/4", they seemed a lot less fragile, but that take a LONG time. An inch takes 9 months to a year. I fed them fine golden pearls, decap bs eggs, and finely crushed flake.

 

[cabinetmkr39]

I have grown White & Black Calvus and Lafubu Comps for me they do best in a net breeder in the tank they where born.
Just my experience Java moss works great and I feed fresh Baby Brine shrimp and also decap and golden pearls,
Best of luck BTW what type are you keeping ?

 

[zendog]

Almost three weeks now and it looks like about 30 still swimming which I'm pretty happy with. They've grown a bit, although certainly they're not at the looking-like-little-adults stage yet.


I've syphoned out the grunge at the bottom a few times, but put a little bit of sponge "squeezin's" in their as well which hasn't seemed to harm them. I would guess the big thing would be if they're in their own tank and a lot of uneaten food builds up and starts creating bacterial blooms, etc. which might do them in. I picked up some Sturisoma at CatCon and I've heard similar things about raising their fry in terms of having a tank with a lot of algae growing, some mulm, etc. so they have a good chance of finding stuff to eat if they aren't getting enough from what you provide. Maybe if I have more batches of fry down the road I'll try some different techniques and see how survival rates vary, but for now I'll keep this up since they seem to be surviving.

Here is a picture of the one I think was the father - a bit tough to tell when there are seven in the tank and I think probably 3 are males. He is definitely the dominant one. I got them through SI Cichlids in a group buy at the BFD and Tony said they are Black Congo White Pearl. The male in particular has a lot of gold/yellow on his face and this picture is about the middle range of his color - sometime jet black with the white pearls and sometimes lighter than this picture.


The fry are still on golden pearls and don't seem to like the crushed flake as much so I haven't fed much of that. I'm going to pick up some frozen BBS at Centerville tomorrow if they have it. I can't find it at the local Petsmarts and Petcos.

 

[dogofwar]

Good stuff!

I'd get them from the breeder box to their own tank (filled with water from the main tank) soon. Much bigger and they can start picking each other off.

For really small fry (think acaras or Festivums), micro-organisms can be great to get them over the hump to golden pearls or other prepared foods. I've been dipping a cup into a tank with a bunch of floating plans, mixing in golden pearls and pouring it into the fry tanks - the best of both worlds for food.

Another tip is to add a piece of Polyfilter (chemical filtration) to each fry tank (or breeder box). It will help keep organics (among other things) in check.

Matt

 

[mchambers]

I've been thinking about the issue of whether to keep fry in a relatively clean environment or not, in part because I've been reading a book called "I Contain Multitudes", by Ed Yong. https://www.amazon.com/Contain-Multitudes-Microbes-Within-Grander/dp/0062368591

The book is about how we are all composed of a multitude of organisms, and it isn't really right to think of microbes as being only harmful. In fact, microbes are essential for life. The author gives several illustrations of animals that are raised in a completely sterile environment, without bacteria (or archaea, for that matter), and do not develop normally. It makes me wonder if we are making a mistake by transferring eggs or fry into clean containers with clean water.

 

[lkelly]

I've been thinking about the issue of whether to keep fry in a relatively clean environment or not, in part because I've been reading a book called "I Contain Multitudes", by Ed Yong. https://www.amazon.com/Contain-Multitudes-Microbes-Within-Grander/dp/0062368591

The book is about how we are all composed of a multitude of organisms, and it isn't really right to think of microbes as being only harmful. In fact, microbes are essential for life. The author gives several illustrations of animals that are raised in a completely sterile environment, without bacteria (or archaea, for that matter), and do not develop normally. It makes me wonder if we are making a mistake by transferring eggs or fry into clean containers with clean water.

Everybody leaves microbes and whatnot.

 

[zendog]

I thought I should update this with some additional experience. A few weeks ago I did a 25% water change and instead of using an air tube to syphon the new water into the tank, I used a regular syphon to speed it up. Half way through I noticed fry swimming close to the mouth of one of the shells a female had been guarding. So after finishing the water change I set up a fresh breeder box and dumped the shell into it getting about 75 or more new little guys.

By the next morning they were all dead as were about 1/4 of the first batch that were up to about 1/3 inch long and had seemed very hardy. I expect it was the shock from the water change, which was probably what got the new batch of fry swimming around so much in their shell. The water probably wasn't exactly the same temperature, but it wasn't too far off. So I'm back to doing the water changes very gradually with the air tube to make sure there any changes in temperature or water chem is very gradual.

I have about 20 left from the first spawn, split to 10 each in the 2 breeder boxes I have and this weekend I plan to put them in a separate tank with water from the main tank. I'm not worried about loosing the second batch since I think they'll continue to spawn, but it was a good reminder of how sensitive little Calvus can be.