Ochre striped Cardinalfish

[IsaacHunt]

I have had a shoal of Ochre striped Cardinals for about 18 months.
Yesterday I noticed two of them had separated from the group and were lurking in a dark corner of the tank like a pair of drug dealers.

not being the judgemental type I ignored their behaviour. Well during feeding time I observed that one of them had a distended jaw which suggests there behaviour was of an adult nature.

so I am seeking advice on raiding the fry and need information on incubation period and care and feeding of the fry.

in the past I have successfully bred and raised Bangai cardinals so I’m wondering if there are any similarities between the care of these two species.

 

[ISpeakForTheSeas]

so I am seeking advice on raiding the fry and need information on incubation period and care and feeding of the fry.

To my knowledge, these guys (Ostorhinchus compressus) haven't been reared before, but a similar species (O. fasciatus) has been. Incubation period likely depends a bit on temperature, but ~5-8 days:

They were kept at 29C (84.2F) and the eggs hatched after 5 days (I'd imagine at normal temps 7-8 would be about right).

Care and feeding help (as best as I can provide):

Sorry, I didn't have time to respond last night, and my answer is a bit disorganized. I hope it helps regardless.

Ostorhinchus parvulus is (to the best of my knowledge) the currently accepted taxonomic name, so Apogon parvulus is an unaccepted synonym.

A quick note on mouthbrooders - I don't know if it would be best to move the male now or not (ideally you would time it so you move him just before the eggs hatch, but you would need to know how long it takes for them to hatch to time it properly), but you will need to have a separate tank for the larvae (the babies).

As a quick note (this is discussed below, but I figured I'd mention it up here to make it gets noticed), rotifers work for some fish, but not others. Based on the lack of cardinalfish aquaculture info I can find and the fact that the closest related cardinal to this one that I know of that was aquacultured was reared with the most success on copepod nauplii, I would assume rotifers don't work for rearing these guys, but I'd probably offer them both rots and pods anyway in case they do work (as rots are generally easier to culture than small pods).

Now, with that out of the way, I'm going to dump a ton of general breeding advice on you (some of which may not apply to mouthbrooders, but most of which will):

"Based on this, I'd assume you'll probably need more than rotifers - I'd guess you'd need Parvocalanus crassirostris pods (or other, super tiny pods - but Parvocalanus are by far the easiest to find on the market at the moment), and you'll probably build up slowly from Parvo nauplii to Artemia nauplii over the course of the rearing.

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!"

Yeah, the one I'm familiar with is "Apogon quadrifasciatus" (with the accepted name of Ostorhinchus fasciatus). They were kept at 29C (84.2F) and the eggs hatched after 5 days (I'd imagine at normal temps 7-8 would be about right).

"The average total length of the newly hatched larvae was 2.6mm with an average mouth gape of 160 μm."*

"most marine fish larvae consume prey that are only 20% of their total gape."**

So, assuming these guys are in a similar boat because they're in the same genus, they're likely going to need tiny feeds. As a note here, Bangaii Cardinals, Pterapogon kauderni, are actually in a different genus and - as mentioned above - seem to have different reproductive strategies than the "average" cardinalfish.
*Source:

Breeding and rearing of the two striped cardinalfish, Apogon quadrifasciatus (Cuvier, 1828) in captive condition - PubMed

The present study describes captive breeding, reproductive behavior and larval/juvenile rearing of Apogon quadrifasciatus. Spawning occurred 25 days after stocking in the breeding tank. Clutch size varied from 2500 to 3100. The males incubated the eggs, the incubation period was approximately...

pubmed.ncbi.nlm.nih.gov

**Source:

Spawning, early development and first feeding in the gobiid fish Priolepis nocturna

Spawning, early development and first feeding in the gobiid fish Priolepis nocturna

www.academia.edu

 

[IsaacHunt]

Thanks for the information.
The tank temp is 24.1c
Have reached out to my pod suppliers to see if they sell the recommended species.

I have a spare tank and air pump so setting up a rearing tank is no issue.

the initial steps are going to be working out the incubation period and catching the fry.
I also have an egg tumbler to be used if I decide to harvest the eggs before release date.

does anyone know if they are fully developed like Bangai or larvae.

A few years back I raised tomato clowns so have some experience on raiding marine larvae.

 

[ISpeakForTheSeas]

does anyone know if they are fully developed like Bangai or larvae.

They're planktonic (pelagic) larvae, so they're not as developed as Bangaii Cardinals - for O. fasciatus, the pelagic stage lasts for ~13 days, then they settle at ~14 days.

 

[IsaacHunt]

To my knowledge, these guys (Ostorhinchus compressus) haven't been reared before, but a similar species (O. fasciatus) has been. Incubation period likely depends a bit on temperature, but ~5-8 days:

Care and feeding help (as best as I can provide):

tried reading the articles but ended up nursing a headache following the convoluted process of accessing the document.

The language and terminology used was way too complicated for my brain plus I am useless when it comes to latino names when straightforward names in Kings English are far easier to read and pronounce

 

[ISpeakForTheSeas]

tried reading the articles but ended up nursing a headache following the convoluted process of accessing the document.

The language and terminology used was way too complicated for my brain plus I am useless when it comes to latino names when straightforward names in Kings English are far easier to read and pronounce

Haha, don't worry - the important info from the article is in the abstract, and it basically just says the baby cardinalfish need really tiny baby copepods to feed on for the first two weeks.

So, basically, you'll probably need to culture some Parvo pods (these are the only pods really on the market at the moment that would be small enough) and either co-culture the pods with the baby fish (i.e. raise the baby fish and the Parvocalanus culture in the same tank) or screen the pods through a 50 micron mesh/sieve to get the first instar nauplii (i.e. to get the newly hatched baby pods) and feed those to the baby fish.

If you need help understanding anything to try and rear these guys, please ask - I can simplify most of this stuff down to any level needed.

 

[IsaacHunt]

Haha, don't worry - the important info from the article is in the abstract, and it basically just says the baby cardinalfish need really tiny baby copepods to feed on for the first two weeks.

So, basically, you'll probably need to culture some Parvo pods (these are the only pods really on the market at the moment that would be small enough) and either co-culture the pods with the baby fish (i.e. raise the baby fish and the Parvocalanus culture in the same tank) or screen the pods through a 50 micron mesh/sieve to get the first instar nauplii (i.e. to get the newly hatched baby pods) and feed those to the baby fish.

If you need help understanding anything to try and rear these guys, please ask - I can simplify most of this stuff down to any level needed.

You are a true gentleman and thank you for breaking it down into bite sized easily digested pieces.

Sadly my pod supplier doesn’t sell the parvo species so if that’s the only type of pods eaten by the larvae I am going to struggle until I find a source.

hopefully they will keep spawning so I get further opportunities to raise the larvae.

 

[ISpeakForTheSeas]

Sadly my pod supplier doesn’t sell the parvo species so if that’s the only type of pods eaten by the larvae I am going to struggle until I find a source.

Yeah, these guys are hard to come by in the UK right now. There are other pod species that could potentially work (like Oithona colcarva), but they're likely going to be just as hard or harder to come by.

If you want, you could potentially try ciliates (I don't know if they would meet the nutrition needs of the larvae or not, but it may be worth a shot):

The Breeder’s Net: The Culture Of Ciliates

Hopefully from this article, you will see the value of ciliate culture for the home fish breeder and understand why we dedicated this month's column to them.

reefs.com