The populations of ‘pods (iso-, cope-, but not so much amphipods) have been growing astonishingly.  As mentioned below, I am becoming concerned that the isopods may be eating eggs and larvae of the slugs.  I muttered to myself “What species of small fish could I add to eat some of the little bugs?” A species that stays small, but has an appetite for small, moving creatures?  Seahorses, of course.

More specifically, dwarf seahorses (Hippocampus zosterae).  They stay tiny, and a small group should be sustained indefinitely on the mounds of live food growing in the Box of Slugs.  There is a nice little outfit called Seahorse Corral that breeds the little guys, plus H. erectus, so I ordered two males and three females to give my idea a try.

Although Fedex mangled the address here, the guy who runs the loading dock at the institute next door was able to call Beth at Seahorse Corral and figure out where I was, and I got my delivery.  They seem to be settling in well, and doing what seahorses do best, mostly sitting in one place and waiting for food to swim by.

Here is one of the little males, looking pretty.  He is one of the more adventurous, having traveled from one end of the tank to the other.

Male Hippocampus zosterae 10/21/14

This little female is the real daredevil, having zoomed all over the tank.

Female H. zosterae. Little, green, and fearless.

So far so good.  We’ll see what they are doing tomorrow morning.

The clusters on the Udotea are gone, and one hopes that some of the little guys will stay alive and settle.  In an effort to improve their chances, I got rid of the old circulation pump (a low-flow Hydor Ekip pump/heater combination with screen over the intake) for a potentially more plankton-friendly airlift system.  The idea was to use an air pump to generate flow, but to contain the bubbles to reduce salt creep from the splash.

Here is the unit, being assembled.  Just some 2″ PVC pipe and fittings.

airlift unit, in pieces 10/19/14

Insert the air stone, and there it is:

Airlift version 1

Here it is in the tank.  The good news is that it does indeed move water and minimize fizz in the tank.

Airlift version 1 in operation

The less optimal aspect is that, when you think about it, a chamber with bubbles rising in it is….. a protein skimmer.  I am still working on keeping glop from being ejected from the top of the unit.  Also, I hope little planktonic guys are not being extracted by the process of foam fractionation.

Nonetheless, we will still have some larvae to work with.   We have at least three egg masses still developing, including this rather spectacular coil of eggs.  Anyone care to count them?

Egg mass laid 10/18/14 or 10/19/14.

Stay tuned for a few more exciting developments over the next few days.

Things got a little slow during lab today, so I put some eggs on a slide and took some pictures and video.  Looking at a still photo, they look fine.  It looks like it has its father’s eyes.  Not sure what all the other parts are.

Elysia clarki embryo 11-12 days old.

But that doesn’t tell us whether they are still alive, does it?  Well, here is a little video.  Not all of them were moving, and it is still not clear whether they are hatching or getting eaten, but at least some are wiggling energetically.  After their brief moment of fame, all went back into the Box of Slugs.

The number of eggs seems to be decreasing, but it’s hard to know if they are hatching or getting eaten by the massive number of isopods in the system.  If I have time, I will have a look at a few eggs tomorrow and see if there are signs of life.

Eggs 10/15/14

I have no idea what triggered it, but someone has laid the first cluster of eggs.  Cassic spiral form, right where they can be photographed.  We’ll see how long they take to develop, and whether any of the little veligers settle, but for now it’s fun to see them.

Nearby a proud parent or auntie.  Which brings up the question of how to refer to a mommy/daddy or uncle/aunt who is a hermaphrodite.