Diadema urchin sperm


New member
I was very fortunate when i had happend to have my eye on my reef aquarium when the large Diadema (long spine) urchin started spawning. It released large puffs of white sperm into the water column at regular intervals. This process went on for at least 3 minutes.

I managed to take a sample from the water near his body and here is what I found:


Diadema urchin sperm, 40x, DIC


Diadema urchin sperm, 40x, PC


New member
Yep, I grabbed a sample right as the urchin ejected the sperm. They were all wriggling their way around the slide.

@ebacon they seem to glow in the second photo due to the illumination method used - phase contrast. The DIC picture is a bit more "natural".