Breeding Journal, Species: Bursatella leachii (Blue Dot Sea Hare)

Good luck with them again!

I found two egg strings on Tuesday, or maybe it was Wednesday.  In any case, I pulled them this morning and put them in a 1L bottle for hatching.  Hoping they hatch out today

These hatched out yesterday and the evening before (finally!)  I have two different "set ups" going for them.  I have some in a 3L bottle filled to the very top and capped.  They have some Iso and tetraselmis (live) and this is set on a germination mat and lit 24/7.  The second container is also a 3L bottle filled to the top, but it has a hole drilled in the cap and rigid airline bubbling.  It has mainly Iso and is also on the germination mat.  

Shannon, I have a question about the air/water interface that traps the veligers.  Even though your containers are filled and capped, doesn't your phyto produce oxygen bubbles under the 24 hr lighting?  And if so, how do you get rid of the "air" created in your containers?

Yep, it certainly does and it really is a big problem and was perhaps the biggest hassle the last time I tried this species.  
 

Last time, I essentially removed the top (I was using parafilm) and added water/removed the air, then put the top back on.  I was using smaller containers (and therefore had a lot more of them going at once) so this became very time intensive.  Especially when too much phyto is added and then it would need to be done two or more times a day.  Not fun.  This time I am trying slightly larger containers and am also going to try treating the larval container more like a phyto bottle (with gentler aeration though).  My hope is that the continuous movement at the surface will help keep any veligers from getting trapped at the air/water interface, however now I run the risk that the aeration itself may damage/kill the veligers.  I still have a non-aerated container going that I will need to remove air from periodically.  I am also rolling some ideas around in my head as to what other setups I could make that would be low maintenance.  I haven't seen any more egg strings from the adults, but I also haven't been feeding them super well.  I think tonight I will be moving them to a powerhead-less tank and let them graze on whatever they find.  

A completely submerged rearing tank would seem to be the way to go. It means you won't be able to check on them as much, though. You pretty much have to let them go through to settlement.

--Andy, the bucket man.
"Not to know the mandolin is to argue oneself unknown...." --Clara Lanza, 1886

Agreed.  Perhaps one of the next egg strings I will give that a go. 

So I finally got a new egg string.  It took forever!  But I think part of the issue was I put them back into a breeder basket and have been trying to get them to eat these spirulina agar blocks that I made.  I think they are eating them now...they disappear (but that could just be amphipods) and they laid an egg string.  So chances are they ate the gel/agar tabs.

I went to pull the egg string this morning and it was gone.  Waiting for the next one!

Found an egg string yesterday (not positive when it was spawned) and I pulled it this morning. It's already turning dark, so I'm glad I pulled it.  I set it in a 500mL bottle with no air for now, in a water bath.  
I also discovered something fun.  If you take a 1 gallon fish bowl, and let the RG Complete fed rotifers that are in it die out and just be lazy and let the bowl sit around for a week or so, you get a fish bowl covered in green slime algae.  Which could possibly be perfect to use for settling B. leachii veligers!  Hopefully I get them far enough along to try!

Oh, and  I have Dunaliella now, which I think I will try with these guys as a food in place of tetraselmis.   I also have a few more new (to me) flagellated phytos that I want to try.  One of them is a pico phytoplankton...I'm not sure if that will be too small, but I may toss some of that in as well.

Did you get these plankton from Carolina Biological?  I'm curious as to which pico plankton you got.

No, I didn't.  And I'm not actually sure I can say where I got it from...I'm really not trying to be cryptic, I'm just not positive I can say; I should probably ask.  It's Micromonas pusilla, though.  I want to go back through the B. leachii papers I've read and see what size phyto they have fed.  M. pusilla may be too small to be useful.

A few days ago I released these guys out of the breeder basket into a 40B that has no powerheads/pumps in it.  There are egg strings all over the place!  I pulled a few last night and only one of them had moving veligers, so I'm not sure if there is a fertilization issue or if the other strings just weren't developed enough.  I will say that the last egg string I pulled never hatched and when I looked at it under the scope there were only a few moving veligers.  Quite odd.
 
Here are some pics from the egg string I pulled last night.  Not sure what the exact spawn date is on this one, but it looked like the veligers were exiting the string (but that could have been artificially induced when I pulled the egg string out if I broke it...)


 
I have a video too, but I am having a hard time (again) getting videos to upload to photobucket.