A complex spawning

I found a third female to spawn from on Saturday morning, and kicked off the three spawnings on Saturday afternoon. I'll talk more about the new Showa female in a future post. For now, here's today's experience with what turned out to be a complex spawning.

I woke up early this morning, did some work then went for a sneaky peak at around 6am to see if anything was happening in the spawning vats. No significant progress to report at 6am, but some enthusiastic behaviour in the Showa's spawning vat. An hour later, and they were spawning.

Out of the three spawnings I kicked off yesterday (Saturday) afternoon, only the Showa spawned this morning (Sunday). I just have the one male Showa, so it was one male to one female spawning.

The Showa spawning was a bit complex in the end, and the one male wasn’t quite enough to do the full job – after 4 hours of spawning, it looked as though the whole thing was over; so I put the female into my males brood fish tank which follows the approach I've taken on all the spawnings this year. The idea is to make sure no eggs are left inside the female to avoid the risk of septicemia - and the males in that tank would do that job for me.

In my males tank are most of my show fish, plus 8 males ranging from 55cm to 75cm that I have for my breeding project.

What happened was, after I moved her into the males brood fish tank - she had another couple of hours of very active spawning at which point, I was starting to become concerned because spawning was still underway, and she was looking tiered.

I was not sure know how long I could leave it before intervening, so I called Mark Davis for some on the spot advice. Not only did he build my fry ponds, and the polytunnel – and of course he’s a constant source of koi keeping advice and basically my koi breeding mentor; but he also very kindly took my emergency call to ask for advice on the live situation.

I am prepared for spawning complexity, but this is the first complex one I've had and Mark's advice was key because he helped me understand what to do under different fish behaviour scenario’s, and in particular he helped me understand the trigger points for moving her to another tank or even hand stripping.

Without going into the full detail – I continued to observe her, and I was finding the balance between giving the males the chance to get the last remaining eggs out, whilst keeping a close watch on the female's energy level. My preference was for the males to remove the final eggs, but I was prepared for hand stripping if that was required.

I netted her to inspect for eggs, but I didn't have to do any manual inspection because just the netting and socking process caused her to shed a few eggs so so I didn't complete the socking process and left her in the vat.

The males' attention subsided after another hour or so and she was tiered – breathing heavily, but still swimming along when she had a break. It felt like very long hour.

Even at this point, there was still the odd male having a final nudge so I netted her again and inspected her for more eggs. In the netting and socking process, no eggs appeared and the same was true after a gentle manual inspection.

The evidence at that point suggested the eggs were out, and I moved her into the females tank for some peace and quiet. Two hours later, and her breathing was back to normal and she was recovering well.

The water quality in both the male and females tanks took a knock back with the spawning activity; both tanks run off the same filtration, so the milt laden water from the spanwing activity in the males tank has spread through the system. I want both tanks to be separately filtered, but I've just not had time to do the plumbing. To dilute the pollutants, I've started a slow but steady water change so around 10% will be changed over the next 12 hours. And I'll continue the water change at that rate for another 24 hours. I am also holding off the feeding to reduce pressure on the filtration. Taking the pond to 0.3% salt solution is a consideration to take the pressure off the koi and aid recovery, but I want to see how the other spawnings end before applying any chemicals to the main ponds.

This has been the most challenging spawning I had – the slow initial spawning followed by the attention of my fresh males when I put her into the males tank make for a complex situation. And it’s basically taken up my whole Sunday. I started at 6am, and left her at 6pm. Final checks late this evening - and she seems fine.

I don't think the situation ever became desperate, but it was a long way off straight forward.

The overall outcome from the Showa spawning is promising; the female is fine, and the eggs she laid are viable. The genetic match between the Takeda female and Takigawa male has potential. I won't know for another 24 hours about the fertilisation rate. I treated the spawning vat with malachite green, and I just hope I get some luck and we at least have a good number of hatchlings.

On a lighter note, here are some pictures I took of the Kohaku fry today - these pics are taken of the fry in their growing on tank. I've cropped and zoomed so you get a closer view of two of the better ones.