foxfair

Breeding log of my Corydoras trilineatus (false Julii Cory or Leopard Cory): [Water parameter] pH: 6.4 Temperature 72-75F ammonia: 0-1.0 ppm nitrite: 0 ppm nitrate: 20-60 ppm (60 was before water change) TDS: 80-160 GH: 5-6 drops KH: 2-3 drops =============================== [Trigger condition and spawning behavior] Spawn was usually triggered by an environmental change, for example a weekly water change of 30% - 50% range would work. Add tap water with the temperature lower than the tank (-2 to -5 degrees F). A few hours later, observe these cory's activities especially if any of them focuses on cleaning leaves of java ferns, swims rapidly in groups and/or digs into sand substrates. I have only one mature female and the rest (5) are all male, but only 2-3 males anticipate spawning behavior. Before and after the famous T pose, the female holds 1-2 eggs in her pectoral fins like us holding something in our hands. Then she will find a spot to place eggs. Mostly on the java fern leaves and roots in my tank. I only found less than 10 eggs laid on glass surface and other places in the past 3 spawns. I know some species of Corydoras will give more eggs in each round, but I only see 1-2 eggs from the female Cory. Also it seems like she likes laying eggs on leaves more than glass surfaces. The stickiness of these eggs (based on my past experience of pulling eggs by fingers): 0-1 hour: Very sticky, the egg shell (or exteriors?) feels softer and you can see a ring of sticky slime (I don't know a better way to describe it) around each egg when placing them on the transparent wall of a breeder box. 1-4 hours: The 4 hour mark is my own rough assumption of the most recent spawning cycle in their activities. The egg shell is harder than the first stage, You can apply pressure to roll it on / off a surface without worrying if it's gonna break. Overall it is sticky enough to move around fingers (thumb to index fingers, left to right hand etc) and different material of surfaces (java ferns, human skin to plastic of breeder box) but still maintain the same stickiness level. 4+ hours: If you pull an egg from point A to B, simply roll your fingers then the egg falls into the water without too much effort, or you have some problem to place it on the wall then it is in this stage. It is between none to a little stickiness depending on the time being laid on the first surface. Stickiness level is not maintained, or it just degrades quickly, I.e. when you pull an egg you feel it is sticky and stays on your finger, but it cannot stick on a smooth surface when placing it in a breeder box. I would say the egg shell is hardened more at this stage, and I usually would not move eggs at this stage - just leave them wherever I found them . =============================== [How many eggs in each spawn] These are the most recent spawns I collected: 118 eggs on Jul 4. 122 eggs on Jul 28. 168 eggs on Aug 4 - exact one week after the above spawn. 89 eggs on Aug 16 - could be a mixed spawn. I don't know if these eggs all came from the same mother or not, because there are some Corydoras schultzei (black Cory) in the same tank. I didn't check the whole tank just pick whatever I could see up, so I believe there were unknown numbers of eggs which are still in the tank. (I still need to measure the egg size in diameter -- to be filled later)

Just got another round of eggs this evening. Because I moved these black cory from the quarantine tank to my community tank, I am not sure if these are purely false julii cory's eggs, or a mix of them and black Cory. I did find some eggs are in different size and shape than others, so I assume I have both. I did not take any photo while rolling eggs out of java Fern leaves, and only found ~5 on the glass and one was at the intake of a canister filter (lol, good save for a cory's life). I tried to identify which female (black Cory) was the candidate for spawning, but I couldn't tell because they are still young. Anyway, I pulled all 80ish eggs out of the tank and moved them to the breeder box. I assume ~4 weeks later I will need to start looking for a new grow out tank due to recent spawning batches, I did release the first juvenile back to the community tank. Even with 3 breeder boxes I kind of feel the pressure of their living space.

I got mine from Flip Aquatics' website which I bought cherry shrimp before, and JDAquatics on getgills.com. I do check aquabid frequently but I am not sure how sellers will pack and ship. One interesting thing I found out was black cory likes playing dead when the environment was changed suddenly. Yesterday I spotted a black Cory showed its belly up for ~5 minutes in the bottom of the tank, and others were stopping on the java ferns without any movement too. I don't plan to breed Corydoras schultzei in a short time, maybe wait ~5-6 months until they're all mature, but I also welcome any surprise before that.

Since @nabokovfan87 is here, I forgot to mention that I set up a quarantine tank for Corydoras schultzei (black cory), which was partially inspired by the video of his bigger tank with black cory. I decided my second Corydoras species would be it. I bought these black cory from two different sources. I believe I saw two female when I put them into the tank, but I don't think they are mature enough to start spawning. So they have stayed in this tank for past three weeks. Today I did a regular maintenance (30% water change) and guess what I found? Eggs on the wall. They are not sticky anymore, so I guess they must be over the first day mark. There are at least 3 places with a bunch of eggs. I spot checked and some of them are unfertilized in white color. I don't want to move them because I wasn't sure about the spawn time. Let's see if any of these eggs could hatch and bring us another surprise.

Spawning actions and eggs in the second batch.

I don't consider myself as a breeder, so the title says it right: I did it by surprise most of the time. I have a 55 gallons community tank, 6 Corydoras trilineatus (NOT the true Corydoras julii even they were sold under this name, most LFS and even Aqua huna make the same mistake), 5 male and 1 female and lots of mollies in the tank. This tank was established for about ~2 years. They have lived in the tank since I started. I was surprised by a tiny cory juvenile on a weekend afternoon, apparently there were some spawning actions I missed, and somehow this brave young one has survived. On the next day, I found another one which was even smaller. I briefly guess the time difference between these two juveniles is about 2-3 weeks. So I start paying more attention to how these Corydoras fish are doing, especially their spawn action. I usually do a weekly 30% water change, so I started checking them after the maintenance. I did trigger their spawning behaviors after the first water change, then I collected 118 eggs in the next few hours to the next day. I was excited!! The hatching procedure was not smooth, I think it was something to do with the water parameters and temperature. I use a Fluval multi-chamber holding and breeding box, which hangs on the outside of my community tank. It took 6 days to see the first fry, unlike the usual 3-5 days I've seen on the Internet. I counted 18-20 fries after 2-3 days, so my setup didn't have a high yield of egg->fry ratio. That's something I could improve in the next round. I fed them Spirulina powder mixed with Aquarium coop's fry food (crush on my palm then mix in the container), then live baby brine shrimps when they were able to consume those live food. But then something bad happened: It was 12 days after the first fry spawned. I found all newborn cory babies dead but only two were still alive in the morning. Granted that I did add some sand substrates on the 9th day, but I don't think sand would impact the water parameter so much to take down almost all baby Corydoras fishes. One died the next day, so all I have is now a single survivor for this batch. I was upset but didn't know what went wrong, the only thing I could do was a daily 30-50% water change for a week. Added a canister filter to power the filtration effect up and hopefully bring more bacteria in. Daily water change seems worked, because they spawned again in 6 days after the big incident happened. I was relieved to count 122 eggs at this time, but I separated them into two breeder boxes. From here, I started doing 50% water change every two days. And I still keep monitoring the water parameters with test strips and the API test kit. I also raised the water temperature from 72 to 78F gradually . The first fry hatched after 3 days, so I think the temperature and water condition control did help. Exactly one week later, the big Mama spawned again with 168 eggs(!!). I guess she starts getting familiar with the spawning cycle and does an excellent job. So now, I have 3 breeder boxes with lots of fries I couldn't count the number, but I only spotted 1-2 dead babies in the past two batches. The first brave survivor is a miniature of their adults now. I also add 3 younger Corydoras trilineatus bought from LFS, hope to add a female and release the spawning pressure of the big Mama. But I do not know if there is actually a female in these three, we shall see in a few months when they grow up. I still need to figure out how to set up a grow-out tank (a 10 or 20 gallon tank would be nice) with limited home space. I'll report back with future updates. The following picture: R.I.P. The first batch of baby fries, only one has survived.

I have a 10g shrimps and minnows tank. I plan to move half or all of them to it once the size is suitable. I also have a ~25g quarantine tank if the juveniles are too crowd fitting in the 10g tank. The first and the last juveniles hatched in a 5-6 days gap, so I'll probably wait until they are at least 4-5 weeks old then plan the move.

Finally got a chance to take a shot of these little juveniles from the bottom view.

I cannot tell you what you should do, but here is what I would do if I am in this situation. First, realize that death is unavoidable in fish keeping, no matter how you want them to live or not, sometimes it is just .... nature. There is another important thing to note: Make sure you only change one thing at a time. If you plan to make A and B and C changes in your mind, pick one only, make it happen and observe the result in a given time (one - two weeks). Yes, it takes time to make changes. Then, let's take a look at your problematic 10G tank. It doesn't have a huge capacity to hold a lot of water, which means your margin of error is smaller. So I would start by getting a bigger filter if you want to stick with HOBs. Or you could add a sponge filter since you are running air stone anyway, the small or medium size of sponge filters on the aquarium co-op shop are both good. I intend to do over-filtering in every tank I run, why? Because I don't trust the number every manufacturer puts on their boxes. If the filter's description says it fits with 6-10 gallons, then it actually means "best for 6 gallons, not so good for 10 gallons -- workable if you are running a low population tank". Keep in mind that you want 4-5 times of your tank size as the ideal cycles per hour, that is, my minimal expectation of the filtration number would go. If you suspect that there are some fungi (funguses?!) or bacteria in the tank and cause the death, I would start a treating plan. Before adding any medication, I will use some aquarium salt (figure out the ratio is easy so I wouldn't mention it here). Let it stay in the water for 3 days and do a 50% water change. You can repeat this process twice or even more if you like. Then start treating the medicine. You will need to study and analyze what kind of disease you are aiming to cure / reduce in the tank, then use the right medicine. Note: You won't feed the fish if you start a medical treatment, so the fish's body systems will actually take the medicine in. For me, I am not against using medication, but it is really hard to NOT feed your fish while doing so. So I prefer the more natural way (salt+changing water) myself. Fouling water: I would use a bare bottom instead of round pebbles for now. Doing so will remove the factor that some fish waste and expired food stuck in small gaps of pebble stones, and it is easier to clean and observe any unwanted waste during the process. I would also test the water parameters (ammonia , nitrite and nitrate) every two days. When changing water, I would only add Seachem Prime to get rid of chlorine and chloramine. One tip: I use a blue painting tap to mark wherever the preferred water level I would want in a tank, so I know how much water I need to remove every time. Maintenance plan: Use an aquarium note app on the phone, or the old fashion way a real notebook to record when and what you've done to maintain the tank. It's also good to track testing results in the notebook or the app. I would start with a weekly water change, 30% each time. If you want to keep using pebble stones, you'll have to make sure to clean the gravel thoroughly at each time. Add Seachem Prime or whatever other brands of water conditioner with the newer water just added in. I would keep doing the above steps and wait at least 1-2 months. Let Mother Nature take care of the tank. If you stick with your plan, it should at least have some changes by itself. Have fun and enjoy watching them change over time, it's amazing!! cheers,

Just curious, whats your nitrate test result with the API test kit (NOT with the test strips)? your tank has a bit of ammonia, no nitrite and unknown nitrate... I'm leaning to either the cycle just crashed or hasn't completed yet. Maybe do a complete fish-in cycle again?

My first survival corydoras -- I found it after collecting my first batch of eggs, and then realized it was not the first spawn. I probably missed the first or even the second rounds of their spawns. I believe that there is another little dude in the same 55G tank, but it's very hard to take a photo because they do have 100% hiding skills. There are tons of mollies overrun in this tank. In one picture you can see a rummy nose tera in the background, so you'll realize the actual size of this survivor. More little squads, this time they are shrimplets in a 10G tank. I didn't plan to get these shrimps spawned because I just got them this month. But they just have their own agenda....