Egg case hitchhiked in on a frag plug - what could it be/
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DaJMasta
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Not a lot to say, some are on the bottom of the cup but don't seem morphologically different, so probably not really settled? I sorted out the white balance and the coral is not all too pleased.
So curious as to what these are. Don't worry about the frag. I'm happy to give you another.
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DaJMasta
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Took a look this evening, and while they look and act mostly the same under a microscope, they're not swimming around nearly as much as before. As they still seem to be active, I think this is more likely a sign of settling soon rather than not being healthy, but I guess that remains to be seen. These little bugs are about 1 week post hatch.
I would say that is a veliger larvae of a sea snail. Could also be a bivalve.
en.wikipedia.org
Veliger - Wikipedia
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DaJMasta
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Hadn't heard the term, but yes, that lines up with the best guess so far.
No settlement yet, took some video with reflected light instead of transmitted light. Much easier to see the shell and I'm getting a bit more depth of field. I can see some algae on their shells already, and it looks like there a few empty shells too, not sure what to expect for survival rate or cause - just observations.
No settlement yet, took some video with reflected light instead of transmitted light. Much easier to see the shell and I'm getting a bit more depth of field. I can see some algae on their shells already, and it looks like there a few empty shells too, not sure what to expect for survival rate or cause - just observations.
Here you go. Looks like it's definitely a snail:
https://invert-embryo.blogspot.com/...udGZdC0Q3HCINgI_uHYJthYGaRoPiVK0eon6StxHLGbKI
https://invert-embryo.blogspot.com/...udGZdC0Q3HCINgI_uHYJthYGaRoPiVK0eon6StxHLGbKI
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DaJMasta
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9 days post hatch, most of them aren't in the water column, but none really seem to be using a foot to move around or grazing like a snail. The ones I spotted all had algae growing on their shells, making them look fuzzy and more opaque. Here's a video of one unfurling from its shell and starting its velum (now that I've been given terminology for them!)
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DaJMasta
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At 10 days post hatch: not exactly settlement, but I no longer see these guys in suspension in the water. When looked at under the microscope, they still have their velum, and they have what looks like a foot (lower protrusion in the picture), but they're not using it like a snail foot yet.
Took this image under the lower power objective in a dark spot of the field caused by a bit of misalignment in the phase ring/condenser, but which actually looked neat - sort of a combination of the phase contrast dark edges and chromatic aberration with a darkfield illumination look.
Took this image under the lower power objective in a dark spot of the field caused by a bit of misalignment in the phase ring/condenser, but which actually looked neat - sort of a combination of the phase contrast dark edges and chromatic aberration with a darkfield illumination look.
At 10 days post hatch: not exactly settlement, but I no longer see these guys in suspension in the water. When looked at under the microscope, they still have their velum, and they have what looks like a foot (lower protrusion in the picture), but they're not using it like a snail foot yet.
Took this image under the lower power objective in a dark spot of the field caused by a bit of misalignment in the phase ring/condenser, but which actually looked neat - sort of a combination of the phase contrast dark edges and chromatic aberration with a darkfield illumination look.
Again. Amazing pictures. This may be one of the best documented snail egg to snail threads on R2R.
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DaJMasta
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Yesterday night, I went to check on things, and I couldn't find any live veligers remaining. Not exactly sure what happened - it could be that the small vessel had a buildup of ammonia or similar and killed the remaining ones, it could be that they were running out of food (still not sure what they should be eating) and they were resting on the bottom in previous days because of it, rather than because they were settling.
Not sure, but too bad that it ended up that way. If I come across more, I won't be QTing them the same way, and instead will just keep them in a larval rearing vessel with a fine mesh, so that I can keep track of their development, but so their water is continuously exchanged with the larger system.
They definitely took longer to settle (again, maybe food related?) than I expected, but I think the chance they were something harmful was probably not high.
Not sure, but too bad that it ended up that way. If I come across more, I won't be QTing them the same way, and instead will just keep them in a larval rearing vessel with a fine mesh, so that I can keep track of their development, but so their water is continuously exchanged with the larger system.
They definitely took longer to settle (again, maybe food related?) than I expected, but I think the chance they were something harmful was probably not high.
Happy to give you another frag with eggs...now that I know where to place the frags.
I know with conches at least, the veligers eat phyto - the specific species I’m aware of used for it are Isochrysis galbana and Chaetoceros gracilis. I’d imagine these guys eat something similar.
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DaJMasta
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Thanks, I was feeding a blend if isochrysis and tetraselmis - I've got chaetoceros as well, but in the last couple weeks I think both cultures got contaminated, so while they're slowly growing, they're partially off color and I expect I will need to restart from another clean inoculation culture.
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