Lettuce nudibranchs eat phytoplankton

[mc-nuggs]

Background: I bought a mini desktop aquarium (0.6 gal) which I have on my desk at work. I do 90% weekly water changes and have a lot of algae for nitrate removal. It has been running without issues for about one month. In this aquarium I have various coral, stomatella snails, and 3 lettuce nudibranchs (Randy, Sandy, and Candy) which I am hoping to breed if possible, since the water flow is low, and the filter grate is small enough that the nudibranchs cannot get sucked in (at least until there are babies).

The nudibranchs usually lay dormant near the water surface where the light is the strongest, about 90% of the time.
I have a lot of different types of macro algae (including hair algae) for the nudibranchs to feed on. I have never seen them feed on any of it.

I dose RedSea brand phytoplankton into the tank for the coral to feed on, since anything else would probably nuke the tank. the phyto is red in color.

Every time I dose phyto, the nudibranchs become active and roam around the tank.

At first, I thought this behavior was just a feeding response (like how inverts will come out looking for food when you dose amino acids in a tank) since everything I have heard about lettuce nudibranchs says that they suck chloroplasts out of hair and other algae. I have also never seen them clean the algae off the glass, even though they regularly move over it.

Randy has been in the tank the longest, maybe 2 weeks now. He started out a deep green in color, but has slowly turned pink, leading me to the conclusion that nudibranchs readily consume (or absorb) phytoplankton. It might be possible that he is bleaching out, but I would think that there would be other signs of poor health (eg. excess mucus, failure to cling to walls, etc), none of which seem to be present.

Just thought I would share to get your opinions or help out anyone trying to keep lettuce nudibranchs. I will update this thread with any additional developments. I've also ordered different phytoplankton, so they get full-spectrum nourishment.

 

[mc-nuggs]

Correction, it's not RedSea phytoplankton.
It's Brightwell Aquatics PhytoChrom.

 

[sixty_reefer]

Following along, it looks interesting and different

 

[mc-nuggs]

Update, I noticed the nudibranchs feeding on hair algae for the first time today. Sandy on the glass, and Candy near the filter. Randy was grazing around the macro algae. He is still pink from the red phyto.

The red phytoplankton has started growing on the walls, and there is evidence Sandy was eating it over the weekend (large patches missing). I am also feeding them green phytoplankton now.

Added one additional mini light to the tank to the tank. So far, so good.

 

[mc-nuggs]

Came back from the weekend and noticed an egg cluster on the glass.

An odd behavior I've noticed is when I feed phytoplankton, I turn off the pump, and the nudibranchs will skim the underside of the water's surface. They actually "weave" their way slowly along it like a snake. This seems to be intentional, as I've noticed different nudibranchs doing it. They will eventually find a wall and move onto it.

 

[Eric R.]

@mc-nuggs Interesting observations! Did you have any luck with the eggs hatching out?

I had some Elysia (I believe they were E. crispata) in a dedicated tank a couple years ago that hatched out, but didn't survive more than a couple weeks. Not sure if it was predation or lack or suitable food sources. There was a flatworm outbreak around the same time the hatchlings all died off.

Also, if you haven't read over it yet, you should check this site out: https://solarslug.info/

 

[mc-nuggs]

New update: I brought my tank home because of the holidays (I have Thanksgiving week off + will not be in the office). I put the corals into my main aquarium and only have macroalgae in this tank with the nudibranchs now.

Randy was slowly shrinking and did not seem to be doing well. I put him in the refugium of another tank. It has low flow and is walled off by filter sponges so he cannot get sucked into the pump. The refugium also has a variety of macro algae and plenty of hair algae. I have not seen him since (godspeed Randy).

I noticed a new egg spiral on the side wall of the tank 2 days ago.

The first egg spiral had a portion which was starting to come off of the wall (swaying in the low flow of the tank), so I used a pipette to suck up a portion and took a first look at the eggs under a microscope.

I wish I could upload movie files here; you can see these little guys wiggle around in their eggs. I spotted two which were rolling continuously in their eggs (non-stop somersaults), but they looked malformed or perhaps underdeveloped compared to the majority (smaller and lacking pigmentation).

They resemble turbo snails in body shape, and have whiskers on their mouths which flutter (reminded me of porcelain crabs, or barnacles).

I read online that they start life in a planktonic stage (oh boy...) and that their survival rate into adulthood is less than 1%. So these little guys are all going to die. Great. At least it won't be as gut-wrenching as losing an entire brood of octopus paralarvae which I got to experience last year.

I'm thinking that tomorrow I'll cut a piece of 200 micron cloth and hot-glue it over the filter grate in preparation for these guys hatching.

Another idea I had is to put the eggs in a petri dish and do daily water changes, but temp control and evaporative water loss might be an issue. I may try this and clamp the dish to the side of my main tank for temp control.

I'm committed to giving it my best shot and I'll update this thread with the results for the benefit of those who follow after.

I regret sucking up a small portion of the spiral; these are not like nassarius snail eggs, which are all congealed on a mat. These are more like balls in a tube. In that first microscope photo you can see a few "orphan eggs" which are now drifting freely. Oh well. There is a complete void of information online about farming nudibranchs. Now you know.

 

[Navareef]

New update: I brought my tank home because of the holidays (I have Thanksgiving week off + will not be in the office). I put the corals into my main aquarium and only have macroalgae in this tank with the nudibranchs now.

Randy was slowly shrinking and did not seem to be doing well. I put him in the refugium of another tank. It has low flow and is walled off by filter sponges so he cannot get sucked into the pump. The refugium also has a variety of macro algae and plenty of hair algae. I have not seen him since (godspeed Randy).

I noticed a new egg spiral on the side wall of the tank 2 days ago.

The first egg spiral had a portion which was starting to come off of the wall (swaying in the low flow of the tank), so I used a pipette to suck up a portion and took a first look at the eggs under a microscope.

I wish I could upload movie files here; you can see these little guys wiggle around in their eggs. I spotted two which were rolling continuously in their eggs (non-stop somersaults), but they looked malformed or perhaps underdeveloped compared to the majority (smaller and lacking pigmentation).

They resemble turbo snails in body shape, and have whiskers on their mouths which flutter (reminded me of porcelain crabs, or barnacles).

I read online that they start life in a planktonic stage (oh boy...) and that their survival rate into adulthood is less than 1%. So these little guys are all going to die. Great. At least it won't be as gut-wrenching as losing an entire brood of octopus paralarvae which I got to experience last year.

I'm thinking that tomorrow I'll cut a piece of 200 micron cloth and hot-glue it over the filter grate in preparation for these guys hatching.

Another idea I had is to put the eggs in a petri dish and do daily water changes, but temp control and evaporative water loss might be an issue. I may try this and clamp the dish to the side of my main tank for temp control.

I'm committed to giving it my best shot and I'll update this thread with the results for the benefit of those who follow after.

I regret sucking up a small portion of the spiral; these are not like nassarius snail eggs, which are all congealed on a mat. These are more like balls in a tube. In that first microscope photo you can see a few "orphan eggs" which are now drifting freely. Oh well. There is a complete void of information online about farming nudibranchs. Now you know.

Any luck with hatching the eggs?

 

[mc-nuggs]

Over the holidays, I fell out of the habit of regular water changes and regular RODI water replacement. Owing to this, I put all the algae, nudibranchs, and eggs (I carefully scraped them off the walls) into a small quarantine box in my main aquarium. I stopped feeding them phytoplankton, and instead put a ton of hair algae in there.

Top view:

Side view (water level is low due to turning off the return pump for the picture):

The eggs must have hatched a while ago as I have been seeing baby nudibranchs pop up all over my main tank. They are yellow in color, not as green as the adults.

Behind the powerhead:

On the glass wall:

On the skull eye socket:

On the frag rack:

On a rock pillar:

I have no idea how they survived in the main tank. I have an enormously powerful UV filter, a side-hanging filter, and moderate flow everywhere. Lettuce nudibranchs are the equivalent of plastic bags in any reef tank as they get swept into the water flow effortlessly, and then get ripped up by powerheads, wavemakers, or even overflow grates.

I sucked up most of these baby slugs and put them into the quarantine box. I left some of them in the main tank since they seem to be doing well just roaming around in there, and the light is probably more intense than in the box.

I have found yet another new egg spiral in the quarantine box, on the underside of some lettuce macroalgae (no picture included).

I have not seen Candy in the box for a few weeks now. Only Sandy remains it seems.

 

[mc-nuggs]

Update: I keep seeing these little guys pop up in my tank. They are slightly larger than before but the most noticable change is that now they have a green hue to them. They generally hide under frags. Sometimes when I'm dusting corals, I will accidentally blast them out. When that happens I suck them up with a baster and put them in a rock crevice.

Side note: I put live sand-sifting clams in my tank for my crown conchs to eat. I have no idea what this guy was expecting to find there

 

[dr.g]

Update: I keep seeing these little guys pop up in my tank. They are slightly larger than before but the most noticable change is that now they have a green hue to them. They generally hide under frags. Sometimes when I'm dusting corals, I will accidentally blast them out. When that happens I suck them up with a baster and put them in a rock crevice.

Side note: I put live sand-sifting clams in my tank for my crown conchs to eat. I have no idea what this guy was expecting to find there

Over the holidays, I fell out of the habit of regular water changes and regular RODI water replacement. Owing to this, I put all the algae, nudibranchs, and eggs (I carefully scraped them off the walls) into a small quarantine box in my main aquarium. I stopped feeding them phytoplankton, and instead put a ton of hair algae in there.

Top view:

Side view (water level is low due to turning off the return pump for the picture):

The eggs must have hatched a while ago as I have been seeing baby nudibranchs pop up all over my main tank. They are yellow in color, not as green as the adults.

Behind the powerhead:

On the glass wall:

On the skull eye socket:

On the frag rack:

On a rock pillar:

I have no idea how they survived in the main tank. I have an enormously powerful UV filter, a side-hanging filter, and moderate flow everywhere. Lettuce nudibranchs are the equivalent of plastic bags in any reef tank as they get swept into the water flow effortlessly, and then get ripped up by powerheads, wavemakers, or even overflow grates.

I sucked up most of these baby slugs and put them into the quarantine box. I left some of them in the main tank since they seem to be doing well just roaming around in there, and the light is probably more intense than in the box.

I have found yet another new egg spiral in the quarantine box, on the underside of some lettuce macroalgae (no picture included).

I have not seen Candy in the box for a few weeks now. Only Sandy remains it seems.

Hi, I was wondering what sort of flow levels you had in your tank? I'd like to get some Lettuce nudibranchs, but don't want to blow them away! Also, what species of algae did they seem to eat the most? I was thinking of getting some, but I've seen some folks post that its often challenging to find the specific type of algae they eat, and I don't want to starve the little guys out!