Berghia Nudis

[Coral reefer]

Hawaiian? I didn’t realize there are different types...

 

[gaberosenfield]

Hawaiian? I didn’t realize there are different types...

Exaiptasia diaphana (the most updated scientific name for the anemones most reefers call aiptasia) are a "cosmopolitan" species, meaning they grow in tropical and sub-tropical waters all around the world. It appears that some populations have been reproductively isolated from each other for a very long time, but we can get anemones from Hawaii to reproduce with anemones from South Carolina in the lab (although we can't get the larvae to settle and metamorphose into adults, but that's another story...). Interestingly, aiptasia from different parts of the world associate preferentially with different species of symbiotic algae (all formerly called xoozanthellae), and different aiptasia populations also invest more or less resources into asexual vs sexual reproduction. The Hawaiian variety we keep in lab (strain H2) reproduces asexually via pedal laceration many times faster than the Floridian or Carolinian strains we keep. My hope is that strain H2 will provide more food for the Berghia nudis more quickly than other strains, but don't let it into your main system or it may become a true plague!!!

 

[The_Lazy_Reefer]

5 Berghia were given to @gaberosenfield. He gave me some Hawaiian Aiptasia. He‘s planning to breed the Berghia for the club in his lab at Stanford!

Nice! That’s promising.

 

[gaberosenfield]

So far, the 5 Berghia nudis given to me by @JVU have grown and appear healthy. They've laid quite a few egg ribbons and I've noticed a number of tiny nudis crawling around, although all seem to disappear within a few days. Maybe they are just hiding somehow. Anyway, I took a few pics for everyone's enjoyment:

A Berghia with one of the first egg ribbons to appear.

Berghia with egg ribbon and aiptasia lit from below.

Berghia egg ribbon magnified about 40x; the embryos are rotating around in their little egg sacs.

Zoomed in view of the previous picture to about 80x; each embryo appears to have two little black eye-spots that aren't apparent in the adults.

After seeing the eyespots in the embryos, I looked more closely at the adults and found the eye-spots: one behind each rhinophore!

Although the animal pictured above is still pretty white, you can see the brown color of Symbiodinaceae algae taken from their aiptasia diet in the nudibranch's cerata (the tentacles sprouting from their sides that contain extensions of their gut). This demonstrates a phenomenon seen in a number of sea slug species known as kleptoplasty: the transport and maintenance of photosynthetically active cells or organelles from a food source (e.g. algae in the case of Elysia species and aiptasia in the case of Berghia species) to specialized organs on the sunward facing parts of a predator. It isn't clear whether kleptoplastic slugs actually derive nutrition via photosynthesis in the pilfered photosynthetic cells/organelles they isolate from their food, but studies on Elysia indicate these cells/organelles remain photosynthetically active in the slugs. These animals may have evolved kleptoplasty as a form of camouflage; if you live among your only food source, it is best to look like your only food source. What better way to look like your food than to fill the most visible layers of your body with the same cells that give your food its color?

 

[JVU]

So far, the 5 Berghia nudis given to me by @JVU have grown and appear healthy. They've laid quite a few egg ribbons and I've noticed a number of tiny nudis crawling around, although all seem to disappear within a few days. Maybe they are just hiding somehow. Anyway, I took a few pics for everyone's enjoyment:

A Berghia with one of the first egg ribbons to appear.
View attachment 19442
Berghia with egg ribbon and aiptasia lit from below.
View attachment 19443
Berghia egg ribbon magnified about 40x; the embryos are rotating around in their little egg sacs.
View attachment 19444
Zoomed in view of the previous picture to about 80x; each embryo appears to have two little black eye-spots that aren't apparent in the adults.
View attachment 19445
After seeing the eyespots in the embryos, I looked more closely at the adults and found the eye-spots: one behind each rhinophore!
View attachment 19446View attachment 19447
Although the animal pictured above is still pretty white, you can see the brown color of Symbiodinaceae algae taken from their aiptasia diet in the nudibranch's cerata (the tentacles sprouting from their sides that contain extensions of their gut). This demonstrates a phenomenon seen in a number of sea slug species known as kleptoplasty: the transport and maintenance of photosynthetically active cells or organelles from a food source (e.g. algae in the case of Elysia species and aiptasia in the case of Berghia species) to specialized organs on the sunward facing parts of a predator. It isn't clear whether kleptoplastic slugs actually derive nutrition via photosynthesis in the pilfered photosynthetic cells/organelles they isolate from their food, but studies on Elysia indicate these cells/organelles remain photosynthetically active in the slugs. These animals may have evolved kleptoplasty as a form of camouflage; if you live among your only food source, it is best to look like your only food source. What better way to look like your food than to fill the most visible layers of your body with the same cells that give your food its color?

Wow, love those photos and discussion!

 

[Hamada]

If there's some available id love to try them out, I have a 100g that has aptisia

 

[pathakm]

Me too. Tired of killing them with Aptasia-x. Seems like a temp solution. I’ve tried peppermints and against my own judgement a copper band. So far I see new baby aptasia popping up everywhere. Don’t know what else to do.

Can anyone on this thread spare a few? I have a IM-30 AIO.

 

[Wlachnit]

Me too. Tired of killing them with Aptasia-x. Seems like a temp solution. I’ve tried peppermints and against my own judgement a copper band. So far I see new baby aptasia popping up everywhere. Don’t know what else to do.

Can anyone on this thread spare a few? I have a IM-30 AIO.

@JVU has been breeding them and should have some...very reasonably priced.

 

[Vincerama2]

I put mine into my display tank, hoping they'll be safe since there are no fish anymore.

I'm wondering if I should have pre-bred them in a separate container and then moved them from that reserve into the main tank.

I'm happy to support JVU with my hand-picked aiptaisa whenever he needs some because he is doing the Bay Area reef community a great service by breeding these guys, and
selling them very reasonably!

V

 

[gmdcdvm]

I picked up some berghia from JVU. He was great to work with. Went over a lot of details about proper care and acclimation. Definitely worth it.
Gerry

 

[Patio]

@JVU has been breeding them and should have some...very reasonably priced.

I think it was a few weeks ago that I received some from JVU and they went straight to work in the tank. Granted I have a small tank, I have not seen an aptasia in at least ten days. It was my first experience with these nudis... very happy I tried this approach.

 

[rygh]

My Aptasia seem to be disappearing !!
Months with nothing after adding the Nudis. But now the rocks around where I added them are Aptasia free.
Still no sign of them when looking though.

 

[gaberosenfield]

Another update on Berghia breeding with pics. This time I used a microscope with attached camera, rather than my phone held up to a microscope eyepiece.
Some of the eggs separated from the ribbon, allowing a better view of the embryo shortly before hatching:

After hatching, the larvae look like little snails with relatively enormous mouthparts (radula). They swim around in the water column (pelagic larval stage), and appear to eat microorganisms like ciliates:

Many of the larvae died after a day in the petri dish in which I kept them for observation, but some dropped their shells and began crawling around on the bottom of the dish (benthic larval stage). The benthic larvae are about the same size as the pelagic larvae:

I also got a much better picture of an adult among some sad looking aiptasia:

There are some conclusions we can make based on these images:

1. Because Berghia larvae go through a pelagic larval phase, they will probably be eaten or removed by filtration systems even if the adults are thriving in our main systems. As everyone, including @JVU says, if you want to breed them you need to put them in their own tank with aiptasia and minimal filtration & flow.
2. During their larval phases, Berghia larvae appear to feed on microbes rather than aiptasia, so they probably need to be provided with some other food source if you want as many of them as possible to survive to adulthood.
3. I saw a number of Berghia larvae that appeared to have been killed by aiptasia. I think it's likely that the larvae are preyed upon by aiptasia until they grow large enough for the hunter to become the hunted.

Overall, I suspect Berghia breeding will be most successful if the egg ribbons are placed into a separate container from the adults with gentle aeration before they hatch. I'm still not sure what to feed the larvae, but I'll post back here if I find anything that seems to work well. The larvae are slightly smaller than brine shrimp (Artemia) nauplii, so those are definitely out. I'm guessing the larvae need to eat single-celled algae or bacteria. So far, I still haven't seen a single new Berghia adult appear in my breeding tank.

 

[Coral reefer]

Rotifer?

 

[Wlachnit]

Very cool vid!

 

[JVU]

I’ve read that the pelagic larval stage when they are swimming freely is quite brief, about a day, and sometimes is skipped entirely if they stay in their egg a bit longer before hatching. My assumption was that they don’t necessarily need to feed during that stage, though I’m sure they’d be happier if they could. I use small tanks with no aggressive filtration for the Berghia, and in those systems I’m afraid to add to much food that would go uneaten for that brief stage. I agree that multiple stage-specific tanks would likely have a much better yield rate, but likely at a significant cost in time/effort.

I love the photo and video microscopy Gabe! Amazing and beautiful. Thank you for sharing it.

 

[The_Lazy_Reefer]

Wondering if any of these are still kicking around. I could use 5-10 to take care of some aiptasia popping back up.

 

[NanoCrazed]

Ditto. I now have a tankful of aiptasia (somewhat on purpose)

 

[Eugene]

What a wonderful creatures - thank you John! 4 of them cleaned my tank in month - I can see one or two left but sure they'll get to it. Highly recommend!

 

[BleepBloopMunchMunch]

I have a few aiptasia showing up as well, but it is not in invasive proportions so I am not in a huge rush, but if there are some of these available at some point I would take some!