Aiptasia, polyp stage, microscope pictures

[mc-nuggs]

I have a small Fluval 5 gallon tank which has a moderate amount of aiptasia (20-ish?), which have been multiplying recently. I have dwarf seahorses in there which I feed hatched brine shrimp.

Anyways, I spotted these tiny specks, about the size of the hatchling brine shrimp, which look and swim like jellyfish. They pulse upward toward the tank light, and then drift down. I pulled out my digital scope and took some images. Thought some folks would be interested to see the juvenile form of this common pest. Nice to know that the aiptasia in my tank are sexually active-- I'll be ordering some berghia nudibranchs now ;-)

I included a ballpoint bic pen tip in one photo for a relative understanding of how small these are.

 

[19Mateo83]

Very cool!

 

[ISpeakForTheSeas]

Slight correction here - those are medusa-stage hydroids, and they're substantially larger than larval Aiptasia. Still cool, though, and some species of hydroids look remarkably similar to Aiptasia in their polyp form.

For those curious what larval Aiptasia does look like, though, Figures 1 and 2 (especially 2) in the link below have some great pics and descriptions:
https://www.pnas.org/doi/10.1073/pnas.2311872120