Reef Discussion

[MagicJ]

As expected, we had an egg laying session tonight. I had to go out at 6.30 tonight but was fairly confident that there would be a nest when I got home given the amount of tile cleaning that was taking place and the visible ovipositer on the female.

These guys are like clockwork now :)

I will take a photo tomorrow night and see how many have been laid but it looks to be a nice sized nest.

 

[MagicJ]

Here is the result of last nights work

503 if I have counted correctly - 4 less than last time :eek

 

[MagicJ]

@Dr. Schell I don't want to get ahead of myself here but I have been thinking

If I transfer the tile to a larval tank, and I have a 90+% hatch rate, then I will end up with 450+ larvae which to me seems a few too many to handle. Now, I understand that I am likely to loose quite a few along the way and I may look one day and they will all be dead, but am I better off only keeping 100 or so from day 1 - it will be easier to feed this number and easier to maintain the water quality.

 

[alan]

if yours go like mine, the 1st few days are the worst. Getting them into the larval tank (though your hatching in there) then getting them to feed. Even at this early stage with mine there were large losses.

From what i read, the 90%+ is for people that are really good at it.

Density of rots still has to be the same, "A rot every 1.5 times the body length of the fish" you will just have more eating them.

 

[Dr. Schell]

you are likely to have heavy losses from feeding failure, water changes, etc. After refinement of your methodology, you will have a better understanding of numbers that survive. Also, don't forget that you will be removing malformed, mal coloured individuals. Just because they survive the larval phase does not mean that they are quality fish. To maintain quality of fish, you will be required to cull.

 

[MagicJ]

OK, two more questions from the experts if I may :)

1. Mesh to sieve out the rotifers - I can buy a 20cm x 20cm piece of 50 micron mesh for around $10. Or I can buy a 1m x 1.3m piece of 48 micron mesh for around $65. Is one sieve likely to last me for a long time i.e. is it easily washed out and re-used ? Or should I buy the larger piece is it will be more cost effective in the medium term?
   
   
2. I understand the relationship between hatch times and temperature. Currently my DT temperature is 25 degrees (maybe dropping a bit below this of a night time at the moment) and the larvae are hatching on day 10 or 11. I have read some anecdotal evidence that larvae that hatch after about day 8 will not survive (i.e. die around day 3 or 4 after hatch) as they will have already used up their egg sac and can't get enough to eat quickly enough to keep them sufficiently nourished. The recommendation is to increase the brood tank temperature to around 30 degrees to speed up the hatch time. Does this sound correct?

 

[alan]

i can comment on the mesh. i made mine into a 50MM pvc pipe, it was WAY too slow. i used a 400 > 75 > 50 tas taking 15 min to filter 1L.

i think mine got slower as it got older.

im keen on some more mesh too, so if you buy bigger, ill help you out. will prob make 200mm filters this time tho, if i can filter it faster, it should be cleaner water, as ill do a better job.


are you going constant rots or batch rots?

 

[Dr. Schell]

1. the nets last a long time but you may want to make a few. go with best value.

2. temp determines metabolic activity. at lower temps, fish developing and hatching at 11 days will have used the same amount of yolk at those developing at higher temps and hatching in 8 days

 

[MagicJ]

2. temp determines metabolic activity. at lower temps, fish developing and hatching at 11 days will have used the same amount of yolk at those developing at higher temps and hatching in 8 days

So the temperature, and thus the time to hatch, should have no effect on the future viability of the larvae?

im keen on some more mesh too, so if you buy bigger, ill help you out. will prob make 200mm filters this time tho, if i can filter it faster, it should be cleaner water, as ill do a better job.

are you going constant rots or batch rots?

OK, I will get a meter of the 48 micron mesh :)

I am planning to try to keep a constant supply of rots - I think you should do the same thing so that if mine crash I know where to find some more :)

 

[alan]

I'm happy enough to do that. I had 2x 10L buskers last time, it was costing a bit to keep them red daily. Worst part was the time to actually get the rots, was taking 15-20 min a day :(

But if you can work out what's needed for photo and rots, ill be keen to have some on the go here again too. Once it warms up, ill try catching all the babys again. prob about 2000 a month.

 

[macca_75]

Hey

Here is the result of last nights work

View attachment 17057

503 if I have counted correctly - 4 less than last time :eek

Hey @Magic - are your clowns still relatively new at spawning? Mine have been going for about 6+ months now and I would get, (i'd estimate), double or triple the batch size of eggs. I'm just wondering if clutch sizes get larger with age?

 

[alan]

my clakii's have been spawning 12 month, 2-2 months clutches were about 1.5"x1.5" now they are 3x3 or larger. I think they get better at it

 

[MagicJ]

Hey

Hey @Magic - are your clowns still relatively new at spawning? Mine have been going for about 6+ months now and I would get, (i'd estimate), double or triple the batch size of eggs. I'm just wondering if clutch sizes get larger with age?

Yes, this is only their fourth nest and the female is not a large fish - probably around 6cm TL. They can grow upto 10-11cm and lay up to 1,500 eggs.

 

[Dave001]

So the temperature, and thus the time to hatch, should have no effect on the future viability of the larvae?

I haven't had any problems with higher mortality rates due to a longer gestation period . I don't run a chiller on my tank, so the fish go from 30c in the summer, down to 25 during winter.
I found with my GSM pair:
30c - 6 days to hatch
29c - 7 days to hatch
28c - 8 days to hatch
27c - 9 days to hatch
26c - 10 days to hatch
You will get plenty of half hatches as the temp changes though, as in, half will hatch one night, the other half the next, so finding a stable temp where the fry will all hatch on the same night, makes it a lot easier on you.

 

[MagicJ]

Thanks @Dave001 - I might have a play around with my heaters on the weekend.

 

[MagicJ]

@alan - I have ordered some of the 48 micron mesh :) I was thinking of using some 90mm PVC pipe to make some sieves - any other suggestions?

 

[alan]

Bigger the better. 50 was too slow. I was thinking 150. I was going to see what fittings eBay had.

Are you getting any larger mesh too? 48 will filter out Rots from water, but what will filter out other crap 1st? I had a 75, I think that was too fine. Maybe a 100-120 1st?

 

[MagicJ]

No, I haven't ordered anything else - you have more experience with this than me but I haven't read about any major issues. Most seem to just turn the air off for 10 minutes to let everything settle to the bottom and then extract the rots.

I will have a look in Bunnings later in the week to see what I can find - I know that I have some 90mm PVC at home so that will be nice and cheap :)

 

[alan]

I used to do the same. I have mine out in the shed, so get home, air off. Play with kids, get distracted, coke back 2 hours later in the dark. I really want to culture then inside, but my sump is super full. Maybe in the weir...

 

[alan]

And I never got a fish past 4 weeks.