Swordtail Fry

[Antinerf]

So I was originally keeping updates about the swordtail fry I have in the emergency section following the death of one of my swordtail adults, but since they're well over a month old now I figured I would move it to its own proper thread. Here's some footage (they're currently 41 days old, I shot this a few minutes ago):
 
http/youtu.be/om087Yi2jOI
http/youtu.be/J7CTQGE4CQQ
 
I've been feeding them Hikari pellets, doing smaller water changes around three times a week (amounts to switching around 6 out of 36 gallons, or around 17% of the water per week) and using a dropper like a siphon tool to remove waste from the net breeder. The plant in the tank is an anacharis, water parameters are:
 
pH: ~8.4
 
Ammonia: <0.25 ppm
 
Nitrite: ~0 ppm
 
Nitrate: ~0 ppm
 
The water quality is pretty good, and the tank itself is nice and clear. I use Sachem Prime when doing water changes. 
 
My main concern is that they're not growing fast enough. Despite efforts to improve the cleanliness of the tank, they're still kind of tiny for their age based on what I've seen from other YouTube videos. Any other advice?
 
Thanks,
Antinerf

 

[GoldenRoses]

Hello,

It looks like your fry are developing nicely, and you are caring for them quite well. But along with water quality and feeding, you must also take info account the amount of space the fish have, in order for them to develop properly.

Believe it or not, keeping fish in breeder nets or boxes can actually severely stunt their growth. The fish recognize that they don't have enough room to grow, so their growth starts to slow, and if neglected long enough, it will cease completely. This can lead to major health problems in the future. Stunted growth means a shortened life.

The fact that your fish are not only small for their age, but have abnormally large eyes in comparison to their body, are classic signs of stunting. At this age, they should be large enough to cohabit with the adults, no problem. Releasing them from the breeder net after a few weeks is crucial for the fry's health.

What other fish do you have in the aquarium?

If you catch stunting early, it's possible for the fish to recover and live a normal life. But they should be moved to a larger space immediately.

Please keep us updated on how they are doing, and don't hesitate to ask any additional questions you may have.

 

[fluttermoth]

You should also up your water changes.

I do 50% every other day, at least, in fry tanks.

Most livebearer fry produce hormones that stop their growth, once it reaches a certain concentration. You need to be diluting that as much as possible.

 

[Antinerf]

Guess I'll get to it. There are no other fish in the tank, but my swordtails are monsters... I'll also take the metal ring off of the anacharis.
 
I think I'll do a test where I release a fry after laying down cover and seeing if the adults eat it or not. 
 
Also worth mentioning: the "strands" of my anacharis plant broke off a few days ago. I started seeing this big black thing, yet I'm not sure as to what it is. It seems to be alive, since it's turning around on a leaf of the anacharis now, and it was on the bottom of the net breeder yesterday. Should I remove it immediately?
 
http/youtu.be/2b8mFCkCmiw
 
This keeps getting weirder...
 
Edit: Should I release 4 or 5 at once just to provide safety in numbers? Another worry I have is that they won't come back up for food. So far they know that when I turn the lights on right after they go off, it's time to eat. However, I'm worried that they'll get too worried with the much larger space. They do have a ton of places to hide from the adults, at least. Also, my heater is whistling. How worried should I be?
 
2nd Revision: After doing a little more research I have unplugged the heater. Looks like my water change will have to wait. For around a year I have had this Aqueon 100W submersible heater without issues. I see some bubbles on the underside, which looks like a sure sign of a leak to me. What do you guys recommend next? I have been eyeing the Jager heaters but they only sell 50W and 250W near me, and I don't want to risk ordering this thing online. Or should I just get the one I had before? I think I may have forgotten to unplug it for a few seconds (I spotted it immediately once the water line went past it).
 
My options for a new heater:
 
-http/www.petsmart.com/fish/heaters-thermometers/eheim-jager-trutemp-aquarium-heater-zid36-16566/cat-36-catid-300016?var_id=36-16566&_t=pfm%3Dcategory
 
-http/www.petsmart.com/fish/heaters-thermometers/national-geographic-trade-aquarium-heater-zid36-21397/cat-36-catid-300016?var_id=36-21397&_t=pfm%3Dcategory
 
-http/www.petco.com/product/113622/Aqueon-Pro-Heaters-Submersible-Aquarium-Heaters.aspx?CoreCat=certonaProductListTopRated_Fish_2Aqueon%20Pro%20Heaters%20Submersible%20Aquarium%20Heaters-113622
 
The one I had before:
-http/www.petsmart.com/fish/heaters-thermometers/aqueon-submersible-aquarium-heater-zid36-16561/cat-36-catid-300016?var_id=36-16561&_t=pfm%3Dcategory

 

[Antinerf]

3rd Revision: Sorry for all the revisions, but I found a fish outside of the net breeder who is pretty much the same age and size. This seems to be a good sign, but he is sticking to the bottom for cover so I suppose using anacharis as surface cover is a must. I just did a head count inside the breeder so I know he didn't jump out.

 

[Antinerf]

A fry tank might finally be in order. I'll keep you guys posted. Thanks for all the help so far!

Antinerf

 

[Antinerf]

Sorry for quadruple post but I've let them loose in the main tank, and the adults don't seem to care at all after an hour of them swimming around. I have some floating anacharis as surface cover.

 

[Antinerf]

[5x post rampage]

Released them into the main tank. Will be getting a new heater on Monday (EST US), which is when I'll do an all-out, 60% change.