Oxina Cardinalfish

[Reef_Freak720]

Anyone ever keep/breed them before?
Seems like the pair I have is ramping up. They've been vibrating all over each other lol

 

[ISpeakForTheSeas]

I know some people have kept them before, but I don't think I've heard of anyone breeding them/trying to rear the larvae. The only cardinalfish from the same genus (Ostorhinchus, though the name Apogon is sometimes used as a synonym for it) that I know has been bred before is O. quadrifasciatus, though I know some people have had spawning pairs of O. parvulus too.

This link has the full paper of the rearing of O. quadrifasciatus and has quite a bit of helpful info (including that they're paternal mouthbrooders and that rotifers don't work for the species, so you'll almost certainly need appropriately sized copepods):

https://www.researchgate.net/publication/235715512_Breeding_and_rearing_of_the_two_striped_cardinalfish_Apogon_quadrifasciatus_Cuvier_1828_in_captive_condition

And here's some general aquaculture advice that may help if you get eggs and decide to try and raise them:

(I really need to get around to organizing this info one of these days.)

"Some general advice that might help:
- Have a tank ready to move the larvae into (basically a tank with an air stone, a dim light, and a heater - a kreisel tank is ideal, but not necessary; you don't want a filter, a skimmer, uncovered pumps/powerheads, etc. - it needs to be as pelagic larvae safe as possible).
- Be prepared to catch the young when they hatch (ideally, you'd be able to move the eggs immediately before hatching into the new tank, but I'm assuming you don't know exactly when they'll hatch) - catch them and move them into the larval rearing tank as soon as possible.

Assuming you have fertile eggs, the advice I would give is this:
- if possible, get some Parvocalanus crassirostris pods too (rotifers are great, and I would expect the larvae to go for them, but some fish larvae are picky and prefer pods over rotifers - having both seems like a good way to ensure you have good, small foods for them, and Antennarius pictus was cultured using Parvocalanus nauplii, so it seems likely to be a good food source for them). Artemia and other larger pod species would likely be good to have on hand too for the larvae as they grow.

- Get various sizes of very fine sieves so you can control the size of the feeders being offered to the larvae as/if needed.

- Add phyto directly to the larval rearing tank. It’s a good method of ensuring that the feeders are gut-loaded and healthy, and it makes them easier for the fish to see (better feeding/survival rates are typically observed with this method).
- Observe and note information about the larvae (things like how big the eggs are, how big the larvae are, when the larvae settle, when coloration comes in, etc.) and the larval behaviors (stuff like if they are attracted to light, how they react to light, if they are attracted to certain colors, what feeders they eat and what what sizes of feeders they eat at what days post hatch, what kind of substrate they prefer to settle on, are they cannibalistic, etc.).

- Watch for developmental bottlenecks and issues with your rearing methods.

- A lot of people run into feeder issues their first few times breeding, so I’d have a backup plan in place to be able to get some feeders quickly if you find yourself needing some.

With regards to the sieves and feeder sizes:
- You may need to screen the feed initially to only offer Parvocalanus nauplii.
- Observing the larvae eating when/if possible is important for telling if they are accepting/able to eat the food you are offering them.

Generally the main thing to watch for at this stage is a bottleneck where the young start dying off - these usually happen after a few days (day three post hatch seems to be one of the most common bottleneck days for fish that hatch with a yolk they can feed off of - if the rots and phyto don’t provide the proper nutrition for these guys, you might see a die off sometime around here). Some fish run into multiple bottlenecks, including some that happen around/after 2-3 weeks post hatch, so you really need to keep an eye on how things are going. Bottlenecks typically occur because the food the fry is eating isn’t nutritious enough for them, or they’re not interested in eating the food offered, or the food isn’t the proper size for them to eat.

if you do run into a bottleneck and lose this batch, don’t get too disappointed by it - this happens frequently in trying to breed a new species (even to the professionals), and every attempt gets one step closer to success.

With regards to the substrate settlement:
- Some species need sand, rock, dark areas, specific colors, or other oddly specific things to settle on/in (from what I've seen, inverts are usually a lot more picky with this), so it may help to have a ledge or cave (PVC should be fine for this, if it's even needed, which I honestly kind of doubt) and a little sand in the larval rearing tank.


That’s all I can think of at the moment - hope it helps!"

This last link gives a bunch of info on rearing difficult species and trying to troubleshoot problems with the rearing:

Has anyone successfully raised Sunshine Chromis from fry?

Hey all, So I have a breeding pair of sunshine chromis in my reef tank. They have laid 3 batches of eggs that I’ve seen so far, and by the third day, all the eggs are gone (I’m guessing the snails knock them off or my purple tang eats them). I managed to collect and hatch a handful from the...

www.reef2reef.com

 

[Reef_Freak720]

I know some people have kept them before, but I don't think I've heard of anyone breeding them/trying to rear the larvae. The only cardinalfish from the same genus (Ostorhinchus, though the name Apogon is sometimes used as a synonym for it) that I know has been bred before is O. quadrifasciatus, though I know some people have had spawning pairs of O. parvulus too.

This link has the full paper of the rearing of O. quadrifasciatus and has quite a bit of helpful info (including that they're paternal mouthbrooders and that rotifers don't work for the species, so you'll almost certainly need appropriately sized copepods):

https://www.researchgate.net/publication/235715512_Breeding_and_rearing_of_the_two_striped_cardinalfish_Apogon_quadrifasciatus_Cuvier_1828_in_captive_condition

And here's some general aquaculture advice that may help if you get eggs and decide to try and raise them:






This last link gives a bunch of info on rearing difficult species and trying to troubleshoot problems with the rearing:

Has anyone successfully raised Sunshine Chromis from fry?

Hey all, So I have a breeding pair of sunshine chromis in my reef tank. They have laid 3 batches of eggs that I’ve seen so far, and by the third day, all the eggs are gone (I’m guessing the snails knock them off or my purple tang eats them). I managed to collect and hatch a handful from the...

www.reef2reef.com

Gosh dang thank you so much for this!

 

[ISpeakForTheSeas]

Gosh dang thank you so much for this!

Hope it helps!

 

[Reef_Freak720]

Believe my female had some eggs. Going to be watching the male's mouth for the next few days