Mass Urchin Spawning in Tank

[Covey]

I hope this is up to the par of Advanced Topics so here goes.

This is the second I've gotten to witness this and this is my best attempt to document it. The both time have been after a water change. The first during my last tank upgrade. By default that was a large water change (~50%) but this time I only changed out 10G out of a 180G total. It also dropped the temp about a degree. What ever the reason it seem to get the urchins in the mood.

I have four what I believe to be Lytechinus vaniegatus, pincushion urchin's. Now that I have had the chance to see a few times there mating seems to follow a script. Again twice now triggered by water changes shortly after the MH main lighting turns off the urchin make a quick dash to the surface of the water. During the first spawning all four went at once. This time two charged the surface.

Horrible pic but I took 10+ pics of this and this was the best.

Luckily my camera takes video as well and if you look closely you can see the male(I think) releasing sperm into the water.


This went on for over a half and hour.

If anyone can help me with Urchin mating habits it would be a plus. One was seemily the male, milking the water with sperm and one the female? was spreading very small but still noticably larger "eggs"

more to come...

 

[Covey]

Like I said the other time I got to see this it was all four urchin this time it was only two of the urchins, for a while...

After a half and hour the larger of the urchins which had been on the other side of the tank started to make its way across the tank as well. It made it way to the overflow about a foot away and went to the surface again. It started milking the water as well.

Again bad pic but I took many and this was the best one.

Again the video happened to turn out a little better.


While I kept an eye on the 4th urchin it didn't seem to join in.

more to come...

 

[Covey]

Now some more interesting stuff.

My skimmers reaction. I have heard with other animals spawning in a closed system that the skimmer will get overloaded and shut down. Mine didn't but it did end up acting awful weird.

Shortily after this all started it started foam these huge slimely bubbles

With the lid off a gaint stack of huge slimely bubbles.

Ok I might be a little odd but out of curiosity I smelt the skimate. It didn't seem normal and actually smelt alot like DT's oysters eggs.

Now just for kicks given the advancements in captive propagation and the fact that I seemily am able to trigger these spawning events, AND even able to gather spawn after it happens. How impossible would it be to possible raise planktonic urchin larve to settlement?

Impossible or not I thought I would at least offer up what I have learned about my urchin pets for you guys.

What do you think?

 

[leeweber85]

cool

 

[tibbs2]

A little off topic, but have you had any trouble with those urchins eating any coral? I've seen those type in the store but wasn't sure how reef safe they were.

They look like a type of rock boring urchins.

 

[Fredfish]

Very cool. Now if you could get them to do this once a week it would make a nice supplemental feeding for some of your corals.

If you want to know about culture protocals for this urchin, I would post on This forum. Urching larvae are used in toxisity studies and Dr. Ron has done a number of these.

Fred

 

[Covey]

Thanks Fred.

Tibbs these are totally reef safe IME except for any thing they can knotch off and run off with as camo. They carry around the stuff for a day or so and drop it. Frags, suctions cup it generally not very bad but everything has to be well glued down.

 

[glaudds]

Here's a shot of my tuxedo urchin spawning...

 

[J. Montgomery]

Urchins have been a "model organism" used by developmental biologists for decades studying interactions between egg and sperm/fertilization. Pretty much every developmental biology textbook has a section on the subject (though probably not what you're wanting to know). Inducing urchins to spawn is very easy experimentally by injecting them with potassium chloride - assuming they have egg or sperm inside of them (I believe electric shocks will do the same thing).

That doesn't answer your question about raising urchins, but if you research the subject you should be able to find a wealth of information on the subject (I'm sure many people/researchers have tried).

 

[wds21921]

Glad to see some Urchin info on here. Other than reproduction there really isn't much info on them anywhere.
I started off with one black and white pincushion urchin and now have 3. The mother (?) had one and then 2 weeks later produced another one. Are they asexual?
Mine had been in my tank for 3 months before producing offspring with no other urchins in the tank. And actually along with Covey's notification, mine also spawned both times after a water change. I just did another 2 weeks ago with no results that I know of yet.

 

[polypman]

My black pacific long spined sea urchin (diadema setosum?) spawns regulary. I ticks me off because it makes my skimmer overflow back into the sump.

 

[Fredfish]

wds21921. Urchins do not reproduce asexually. The two urchins that recently appeared are probably hitchhikers that you have just noticed.

Fred