Things do not get a whole lot more slug-errific around here than they were this week. There have been exciting developments in both boxes of slugs, and it feels like spring will be a good time for Elysia here in Maryland.
In Box of Slugs 1, the group of E. clarki that arrived from Carolina Biological in December has fattened up and started laying eggs. I hope this perfectly coiled mass symbolizes the beginning of a productive time for this setup. With a few new ideas, I think we should be producing small slugs by the dozen.
Box of Slugs 2 is has been even more fun. The miniature slugs have been growing rapidly, moving quickly from tiny wiggly objects to small versions of their parents.The one below is looking very much like a proper E. clarki.
Nonetheless, they are still babies. For a sense of scale, here is one of the youngsters perched above mom/dad on a Penicillus plant.
Finally, and possibly most exciting, KP Aquatics let me know that the had collected some E. crispata this week. As the project has developed, I have tried to find suppliers who can provide me with the three North American species, E. clarki, E. crispata, and E. diomedea. In the past, I have ordered “lettuce sea slugs” from various suppliers, and always received E. clarki. Don’t get me wrong, E. clarki is a wonderful species, but I was a bit frustrated that the suppliers did not seem very interested in which species they were shipping.
That was not the case with KP Aquatics. After they sent the first batch of clarki, which produced the lovely offspring pictured above, I corresponded with Kara, who seemed very interested in the differences between the species. It was refreshing that they truly wanted to understand the organisms that they collect.
So, Philipp emailed me this week that they had five crispata, and I decided I had to have them. Shipping went fine, despite the frigid temperatures, and they settled into the smorgasbord of Penicillus, Halimeda, Avrainvillea and hair algae without a hitch. Although I should love all slugs equally, I must say the new kids are the real beauties of the collection.
As always, there has been plenty to keep us busy after our return from Bonaire, but we have had a little time to look in on the Boxes of slugs. Seahorses and slugs are doing their thing in B.o.S. 1.0, but no new egg masses or babies as yet.
In Box of Slugs 2.0, the new plants have been enjoying the nutrients and growing well. Unsurprisinlgly, hair algae (looks like Derbesia) has also been spreading exuberantly. Not great for aesthetics, but good for Elysia.
One nice development was the presence of a small egg cluster that appeared by the time we were back. Age is not known, but they will presumably hatch within the week. Not collecting these guys, because the tank may be conducive to the settling and maturation of little sluglets. Why would I think that? Keep scrolling down.
When I glanced at the tank yesterday, I saw some interesting shapes, and thought “goodness me, could it be?” Indeed it was, little wiggly guys with parapodia, rhinophores and chloroplasts! There appeared to be at least half a dozen of them.
Unfortunately, I only had the Canon Powershot SX30, which is unbeatable for taking photos of wildlife from a distance, but rather poor for macro photography. Will bring the Canon G12, home from the office to get some better photos. .
A little math suggests that their eggs may have ridden in on one of the plants, rather than being deposited by the current residents. On average eggs from Box of Slugs 1.0 take about 16 days (16.7) to hatch, and then settle after another 3 – 4 days. The guys pictured above appear to be at least another week beyond that. The parents arrived on 1/5/15, and the babies were visible on 1/25, less than 3 weeks later, which seems like breakneck speed. The water temperature is a little warmer for this setup than for B.o.S. 1.0 (~25 C vs ~23 C), but it still seems a stretch for the eggs to be deposited, hatch, settle, and then grow to the point of being miniature slugs in such a short time.
Anyway, it is an exciting development, and I hope that the youngsters will avoid the hazards of tank life and grow to maturity.
I know you have all been eagerly awaiting the most recent slug photos from our trip to Bonaire. We had hoped to find some of the less common species, such as E. ornata, E. subornata or E. picta, but efforts to find a local expert to help locate suitable habitats were not successful this time around. Apparently, not everyone is as fascinated by this marvelous genus of slugs as I am. I gave up rather quickly trying to explain that, yes, I know that lettuce slugs (E. crispata) are common on the western side of the island, and no, I am not looking for colorful nudibranchs. Easier to nod my head enthusiastically.
Nonetheless, there were plenty of E. crispata to be had, which was just marvelous. Here are a few of the little beauties we found. One characteristic of the species in the variability in color, and this group shows a little of the spectrum. The strobe failed early in the trip, but the slugs’ preference for shallow water provided the opportunity for available-light photography.
Below is a pastel green specimen, found at Margate Bay.
These two blue and green fellows were found huddled below a large gorgonian, next to a nice piece of fire coral. In the shallows of Red Beryl, one of our favorite sites at the south end of the island.
Below is “Tridachiasaurus,” the biggest slug I had ever seen. Hard to get a sense of scale in the photo, but notice the relative size of her rhinophores (normal sized rhinophores, dwarfed by a large body) and intense ruffling of her parapodia. Photographed at Andrea I, a nice dive site with relatively easy entry and exit.
Also at Andrea I, another blue and green specimen, showing the characteristic large, white spots on the midsection.
Here are a few other shots from among the hundreds. They may not be slugs, but it is my site, so I can post what I like.
As described in Slugkeeping FAQ, one excellent way of having a box of slugs is to set it up as a refugium (a fish-free zone that allows proliferation of plants and small organisms) in line with a marine aquarium. The plants can make use of the nutrients (phosphate and nitrate) produced by the fish and food, reducing their concentrations in the display aquarium while providing food plants for the slugs. Further, supplementation of calcium and carbonate for corals will also support growth of calcareous algae, such as Halimeda or Penicillus. The only concern is avoiding pumps or strainers that the slugs will inevitably encounter and be killed.
A 27 gallon cube (20″ wide X 18″ deep X 20″ tall) was a good fit for the available space, and I found a used stand that fit with the decor reasonable well. To accommodate input from the coral reef tank, and overflow back to the sump, I drilled a couple of holes in the back, and added bulkheads plus fittings.Because the flow through the tank will be very low, there is no need for fancy overflow systems.
Then it was just a matter of adding sand for the plants. For a little topography, I added a large-ish piece of base rock. In case flow from the main tank circulation fails, there is also a Hydor heater/pump combination to act as a backup. It has a sponge attachment for the intake that ensures slug safety.
Nice thing about adding a tank to an established system is that it is ready for inhabitants. KP Aquatics (formerly SeaLife Inc) sent me a nice batch of macroalgae, and I indulged myself in a few photosynthetic gorgonians as well. The Elysia clarki settled in well.