Apogon leptacanthus - Breeding Log

[mwp]

Well Peter, 2 Premnas is a better track record than my own!!!

3-1-06 - - it's been about 9+ hours since the "hatch". Got up a few minutes ago and found that indeed, most off the egg mass had died (a clump of white larvae...when they're dead they turn white pretty quickly!). Obviously the parents will do a better job of hatching than the "waving a stick by the mass" technique I came up with.

Furthermore, sometime overnight the airline came out of the cup. I fear I may have had very low dissolved oxygen levels and lost some of the fry.

Still, I have relatively a LOT of larvae to work with on this 2nd spawn. It's tough to estimate the number; looking lengthwise through the specimen cup you can't see through the other end...from the side it's just "green" but the larvae still blend in pretty well.

Last night I harvested some rotifers and let them sit with a few drops of selcon before seiving and adding to the cup this morning. As with my first batch, it *appears* that the larvae are feeding off the bottom of the specimen up.

I'm still anxious about placing a random black plastic bag around the cup, and some of the reading on the "Greenwater technique" leads me to believe that they *may* be OK without the darkened sides and bottom since there is so much algae in there.

Well, like last time...we'll see...

MP

 

[mwp]

Around 11:00 AM the rotifers I placed in just an hour or two before appeared to be GONE! Did the larvae really eat that many rotifers that fast?! Well, I harvested another 1/4 gallon from a culture and fed it immediately + have another 1/4 gallon concentrated and enriching with Selcon as I type this. It definitely looks like we have 40 or so strong viable larvae.

MP

 

[mwp]

At it again - had to place 1/2 of the concentrated rotifers in around 2:00, and now 3:30 they're already starting to look a bit thin again! I took out one of the larvae and examined at 10X - it sure looks like his belly is FULL of all sorts of stuff, but perhaps mostly rotifers?

I'm taking this all as a very good sign so far!

MP

 

[mwp]

Alrighty, the rotifers AGAIN started looking "thin", so I added the rest of the selcon enriched ones I started this morning and also added 50 ML of the Nannochloropsis. That basically brought it back to the point where I can't see the bottom of the specimen cup nor can I see all the way through it lengthwise. So far that "level" seems to be working well, so I'm going to stick with it. Lots of little larvae running around, still looks like they are feeding and the largest difference (From our first brood) is that they are all staying in the WATER COLUMN vs. the sides and/or bottom.

MP

 

[Julio]

Glad to hear you are taking on this brreding project. Keep us posted, does anyone know how long they take to mature?

 

[mwp]

Julio, the only thing I can say is that I am aware that a LOT of people have these spawn but no one to my knowledge has raised this particular species. ORA has produced A. compressus which *SHOULD* be similar in rearing requirments to the A. leptacanthus and A. margaritophorus I'm working with. Of course, they're not about to divulge any info. I pretty much have Frank's information suggesting that they need rotifers as a first food (which, after seeing how small they are, kinda became a "DUH" type of concept).

In watching what's happening with the larvae, I HONESTLY think I underfed the first batch. Having the 40+ running around the rotifer doses seem to be cleared out PRETTY QUICKLY. However, with 40+ larvae I'm not as worried about "overfeeding" anyway. If this is indeed feeding, that would also explain why the phyto hasn't been clearing out very fast...the babies might be eating up the rotifers fast enough to prevent the rotifers from eating all teh phyto. Well that and my phyto cultures are more dense this time around. Still aching for some T-Iso but as I've also started supplementing with Selcon this time around, perhaps things will go more smoothly. Gonna examine a larvae before too long this evening and will report back on "stomach contents"!

MP

 

[mwp]

Well, 10X just isn't enough...time to plunk for a microscope It sure LOOKS like their bellies are full of rotifers, at least that's what my eye perceives. Basically the gut region looks "fat" and kinda "marbled", i.e. take a bunch of rotifers and squish them together and look at the mass....that's what the larvae gut looks like at 10X.

FWIW, I discovered that part of the reason the rotifers are disappearing is that they are settling on the bottom of the specimen cup....the "gunk" that was collecting on the bottom appeared to be mostly rotifers but also some algae clumps / other detritus. So, I stirred it up - perhaps that will keep the cardinalfish happy until morning? Oh, and the other interesting part...rotifers of a wide variety of sizes in the bottom junk...some rather small but not necessarily males (did not see any "eyespots"). So maybe I have some younger or "s strain" types mixed in, and perhaps that wide variety of rotifer size will help keep these guys going long enough to get them on brine nauplii. If I can get them on brine, viola, we should have some babies!

MP

 

[mwp]

One other quick observation - at just shy of 24 hours in some of the larvae are starting to gravitate towards the bottom of the container. All still have a good flight response when being hunted down by a pipette...that's a good thing

MP

 

[mwp]

That's right, what the heck, the specimen cup was actually looking a bit less "transluscent"...algae numbers definitely did get a dent through the course of the day. So, I've added in 50 ML Nannochloropsus, 50 ML Nannochloris, and 25 ML Tetraselmis. Earlier today I added 1 drop of Prime, and I may do so again just to be safe.

MP

 

[Julio]

This hobby will be slow goign because people like ORA will not share info on how to breed certain species just because they want to control a market, if they are so concisous about consrvation then they should share the info with the rest of the world for the good of the hobby and stop worrying abotu money.

 

[Kathy55g]

They have to worry about money. This business has a dismal track record.

 

[mwp]

Well, we have an abrubt end to spawn #2 - I woke up this morning to find 40 some odd bodies at the bottom of the specimen container...1 baby still alive and listlessly floating around.

Oh well...I guess I did something really "wrong" and I'm going to guess it was that last addition of phytoplankton before lights out. Perhaps that extra phyto going into respiration mode altered the water chemistry too much. That's my guess for now.

They were doing so well up until that point

Matt

 

[BrianPlankis]

Matt,

Sorry to hear about the loss of spawn #2, hopefully after the move you can put any hatches into one of those 10 gallons you mentioned, that should help with water chemistry a great deal.

Did you have any air bubbling into the specimen container?

Brian

 

[mwp]

Yeah Brian, I actually did have a airfeed going, about 2-3 bubbles per second. I had also been doing period changes of a cup of water at a time...generally every few hours. Depite all that, something must have been too much for the poor little guys.

Yes, the 10 gallons...I can hardly wait!

Matt

 

[mwp]

3-8-06 - Another spawning? Well, it sure looks like our male is holding yet again! Female #2 is again guarding him, but if you ask me, I sure think he spawned with female #1 as the later is VERY skinny now. This spawn happened sometime in the last 24 hours or so - with the new place the tanks have been relatively unattended. Not sure how the Friday move is going to affect this spawn...probably will just end up eaten or spit with nothing I can do about it.

MP

 

[mwp]

So, looking at the dates, spawn #3 likely occured somewhere between 15-16 days after spawn #2. So, it looks like if you really get these guys cranking the male could be fasting roughly 50% of the time in a given month, with 2 spawns every month, and possibly upwards of 300-500 (or more) larvae in a given spawn. That's TON of cardinalfish!

 

[mwp]

Just a quick note - our male leptacanthus held through the ENTIRE MOVE! SWEET!

MP

 

[mwp]

Well Harumph - somewhere after the 12th the male either ate his eggs, spat them out or they hatched out without me noticing. No big deal...we're still recovering from the chaos of the move.

This tank now has a 10k 150 watt metal halide over it...the cardinals are sure huging the rocks more than the did before

MP

 

[Julio]

Hye MP,
is the male in a breeding tank by itself or do you keep in the main tank?

 

[mwp]

Julio, all my male cardinalfish are currently brooding in the main tank with the rest of the fish...I suspect it's part of the reason why all the Bangaii clutches and A. margaritophorus clutches have failed. Now that we've moved I have a 10 gallon for larvae, brooding or QT but I haven't gotten it set up yet. But here's the news:

3-23-06 - sometime on the 23rd the Threadfins spawned again. It's NOT a huge mouthful, but this is not surprising as the fish were not heavily feed for the week or two leading up to the move. Obviously things are going just fine despite the disruption! This puts hatching day right around the 31st - my rotifers haven't recovered yet so I'm hoping maybe someone else wants to volunteer to give the larvae a try (if I get another successful batch this time).

MP