In only a few weeks, the first batch has gone from barely visible (see the previous post) to nearly adult.

A week ago, it was time to move the four survivors into tanks with the grownups.  They had been weaned from Bryopsis plumosa to B. pennata, and were big enough to avoid being eaten by most of the worms and amphipods that inhabit the boxes of slugs.  As far as I can tell, they all survived once their rhinophores and parapodia were fully developed, so they are sturdy little gals.

This is the best photo I could get last week of a youngster exploring her new world in the home tank.  I found her egg mass on 12/30/17, moved her to the USG system, grew her up, and now she’s home!  She’s a little over 1 cm, I would guess, and mom (dad?) towers over her.  Elysia look about the same whether they are happy, sad, scared, excited, angry, or bored, so I am not sure if the parent slug looks proud.

Baby Elysia clarki, below mom’s head, in Box of Slugs 2.0. 2/18/18.

After only a week of stuffing herself full of Bryopsis, she has nearly doubled in size.  Still dwarfed by mom, but on her way to adulthood.

Young Elysia clarki, with her mother. Box of Slugs 2.0, 2/25/18.

As the older of her parents becomes paler and slowly slides into senescence, it will soon be time for the little ones to take over as matriarchs.  We’ll see how long it takes before they produce their first eggs.

After passing the first hurdle, getting them to eat, everything should be easy, right?  Well, there are plenty of things that can go wrong.  Predators can sneak in with the food algae (you don’t have to be too big to eat a lot of hatchling slugs), and pathogens can decimate a whole brood.  Nonetheless, a few of the first batch have grown, sprouted rhinophores, extended parapodia, and look like teeny Elysia!

Miniature E. clarki, about 10 days after first meal. 2/5/18

They are currently living in a modified specimen container (like they use to catch fish at the pet store).  I drilled a few big holes in it, and covered them with fine nylon mesh to keep the babies in.  They get a constant, slow flow of UV-sterilized artificial seawater, and have a variety of algae to choose from.  They still seem to prefer Bryopsis plumosa for the moment, although they may be sneaking tastes of B. pennata.

Teeny E. clarki at about two weeks after first meal. 2/8/18.

It has been hard to get a proper measurement at this point, but they are about 2 mm long, are somewhat visible to the naked eye, and can be easily observed with a simple magnifying glass.  The photos above were shot with the macro setting of a digital point-and-shoot camera, so they are rapidly leaving the microscopic world!

Fingers crossed that they continue to grow.