Monthly Archives: April 2015

New kids in the growout tank

The slug colony is squeaking along toward full function.  The next batch of plants arrived from KP Aquatics this week, so the broodstock and growout tanks are smorgasbords of macroalgae.

With the growout tank ready, I added the first youngsters from Box of Slugs 2.  This batch consisted of two medium-sized and one small girl, and all seemed almost jubilant once they entered the tank.

The two largest could be twins.

New girls in growout tank, 4/18/15.

New girls in growout tank, 4/18/15.

The little one is keeping an eye on big sister.

Big and little sister in growout tank, 4/18/15.

Big and little sister in growout tank, 4/18/15.

Moving the next generation into the system here should take a little pressure off the fodder in BoS 2.  At some point I should get a better idea of the algae requirements on a per-slug basis.

Box of Slugs 1.0 upgrade!

After months of planning and anticipation, the new slug facility is up and running at Shady Grove.  The original “system,” if you could call it that, was a 20 gallon long tank with an Evergrow LED fixture to supply light and a Hydor Ekip thermopump to provide heat and circulation.  It worked fine in terms of egg production, and the adults seemed quite happy.  The new system has a separate growout tank for baby slugs, a sump for equipment such as the heater and an automated topoff system to make up for evaporation. It will also have a hatchery tank, in which the eggs and veligers will have constant circulation of fresh, pest-free water.

After the shelf was built and painted, the system was set up in one of the lab spaces (no carpet, spill kits at the ready).  For this test, only the 15 gallon broodstock tank and sump were used.

Preliminary test broodstock and sump

Preliminary test broodstock and sump

Then water was added…

Wet test, broodstock and sump

Wet test, broodstock and sump

The plumbing and hardware appeared to function adequately, so it was ready to be set up in the office.  The rack was moved into place and the sump was filled from the Bryopsis growout tank (photo below).  For the final fill, I waited until I could get started first thing in the morning, so that I would have most of a day to keep an eye on it in case of unanticipated redirection of flow (i.e., flooding).

Box of Slugs 1.1, rady to be filled and have livestock moved in.

Box of Slugs 1.1, ready to be filled with water and livestock.

Then it was time to commit.  Water, sand, plants, and slugs all had to be moved in an orderly way.  In an hour or so, everyone was settled in their new homes.  The seahorse had been moved to Box of Slugs 2 to minimize her stress, but all of the adult slugs, the broodstock, took their place in the 15 gallon tank on top.

Box of Slugs 1.1, up and running.

Box of Slugs 1.1, up and running.

So there it is.  The main slug tanks, for adult broodstock and growing youngsters, now have dividers to keep the Bryopsis from completely overwhelming the other algae.  Heater, topoff valve, and pump are in the sump, where they can’t bother the slugs.  Flow from the sump to the rest of the system passes through a reactor filled with activated carbon, to prevent possible inhibition of slug growth by secretions from the algae.  It should also reduce any odors produced by a system packed with seaweed.  Having a sump makes it easier to dose with calcium, bicarbonate, nitrate and phosphate without worrying that some is getting dumped on the slugs’ heads.  As an added bonus, the tank is not taking up valuable real estate in the middle of my office.

The slugs seem happy in their new home.  They are exploring, feeding, and starting their mornings by basking in the sun.

E. clarki in new home, checking temperature

E. clarki in new home, checking temperature

Elysia clarki basking in new home

Elysia clarki greeting the morning sun in new home

Now that phase 1 of B.o.S 1.1 is finished, I will be adding more macroalgae and move some of the the E. clarki youngsters from Box of Slugs 2 into the growout tank.  The final phase will be to get the hatchery on line, to have more control of the timing and numbers of baby slugs.