Ercolania endophytophaga

[Peter Houde]

I am surprised no one has posted anything about Ercolania endophytophaga. It's an extremely small nudibranch that lives inside of Valonia and devours it from the inside out (see https://reefidbooks.com/sea-slug-inside-bubble-algae/). I don't have a bubble algae problem, but one pops up every now and then so there must be more hidden away somewhere I can't see them. I'd love to introduce this nudibranch into my aquarium. It is reported from the Great Barrier Reef, Queensland as well as western Australia, the Philippines (Anilao), and Okinawa Japan. Does anyone know a commercial resource for it. Is anyone game to become a resource for it?

 

[mcarroll]

I see no mention of "Valonia" algae with respect to these guys......but I also know that's a guess at the ID of your algae. The algae they target is in another Family.

 

[mcarroll]

I am surprised no one has posted anything about Ercolania endophytophaga. It's an extremely small nudibranch that lives inside of Valonia and devours it from the inside out (see https://reefidbooks.com/sea-slug-inside-bubble-algae/). I don't have a bubble algae problem, but one pops up every now and then so there must be more hidden away somewhere I can't see them. I'd love to introduce this nudibranch into my aquarium. It is reported from the Great Barrier Reef, Queensland as well as western Australia, the Philippines (Anilao), and Okinawa Japan. Does anyone know a commercial resource for it. Is anyone game to become a resource for it?

Forgot to mention that's still a cool find!

They are not the only kleptoplasts out there, BTW. And this is the first one folks have thought about using for control....but apparently they don't eat much of it, just enough to become solar powered, then they go on about their business. Not a great control option.

https://en.wikipedia.org/wiki/Kleptoplasty

 

[Peter Houde]

I see no mention of "Valonia" algae with respect to these guys......but I also know that's a guess at the ID of your algae. The algae they target is in another Family.

Here are two online references to Ercolania consuming Valonia (Ventricaria):
https://en.seaslug.world/species/ercolania_endophytophaga
https://www.seaslugforum.net/find/ercoendo

I'm uncertain why you seem to question my ID of Valonia, or others IDs of Valonia from which they collected Ercolania

 

[mcarroll]

Here are two online references to Ercolania consuming Valonia (Ventricaria):
https://en.seaslug.world/species/ercolania_endophytophaga
https://www.seaslugforum.net/find/ercoendo

That appears to be a hobby website and I don't see where the algae ID was validated in any way....most bubble algae looks very similar to the naked eye. Interesting, but something more authoritative (peer-reviewed, etc) is nice when available.

I'm uncertain why you seem to question my ID of Valonia, or others IDs of Valonia from which they collected Ercolania

There are multiple families of algae that look a lot like Valonia, so it's a question. Not really "my question".

And sorry I should have posted that I ran a search on Google Scholar where I found this ref:

https://www.researchgate.net/profil...th-notes-on-anatomy-histology-and-biology.pdf

I think I crossed up the species names when I was reading about their new species that is the subject of that article.....but there is a ref to Jensen(1999) where he says your "endophytophaga" species seem to eat valonia in aquariums, but sounds like it's not their native choice either.

Considering literature data on food organisms and feeding strategies, only one species can be compared with our new species here, Ercolania endophytophaga described by Jensen (1999). Ercolania endophytophaga feeds on Struvea plumosa and in aquaria also Valonia sp. (Jensen 1999).

Unfortunately, Google Scholar comes up completely dry when I try to find that 1999 article by Jensen tho.

If there's no link, it didn't happen!!

;)

But seriously, try looking for that Jensen article if you're curious as I am. (Post the link if you find it, pls.) Sometimes they will mention their sources in the article, but they might've collected it themselves for the experiment.

 

[Decamicron Labs Verified Sponsor]

Another point of taxonomy, this is not a nudibranch. This is a sacoglossan.

However, the idea of using it to control bubble algae is ecologically sound

 

[mcarroll]

Another point of taxonomy, this is not a nudibranch. This is a sacoglossan.

However, the idea of using it to control bubble algae is ecologically sound

I don't think they will work for control because they don't wipe out the algae they just use some of it to harvest chloroplasts which can feed them for anywhere from weeks to months. Perhaps if you could have LOTS of them in your tank...

This is definitely not the first time this idea has come up, but it's usually in relation to Bryopsis.

I've never seen anyone source them either.....so aquarium trials have probably never happened, at least not outside of the apocryphal Jensen(1999) article that supposedly exists (but can be found only in citations). ;)

Sounds like a good experiment if someone can find them and try it. It'll be the "new berghia"! ;) ;)

 

[Decamicron Labs Verified Sponsor]

I don't think they will work for control because they don't wipe out the algae they just use some of it to harvest chloroplasts which can feed them for anywhere from weeks to months. Perhaps if you could have LOTS of them in your tank...

This is definitely not the first time this idea has come up, but it's usually in relation to Bryopsis.

I've never seen anyone source them either.....so aquarium trials have probably never happened, at least not outside of the apocryphal Jensen(1999) article that supposedly exists (but can be found only in citations). ;)

Sounds like a good experiment if someone can find them and try it. It'll be the "new berghia"! ;) ;)

It would be interesting to try. We can only speculate until somebody does. I do not want to jump to any conclusions, there is not enough theory or evidence.

There is a major problem with ecology. In the wild, they dig into bubble algae as veligers, and eventually get too large to leave, and are trapped inside for the rest of their lives. It would be difficult getting one into a bubble algae and its not clear whether the inside and outside surfaces are both suitable for feeding. The only time they are outside of a bubble is when they are veligers.

When I was working in sea slug systematics, I kept a pair of Elysia crispata that laid eggs very often, but their veliger stage was too long for a reef tank. However, their veliger stage is supposedly lecithotrophic, meaning they do not food when they are veligers. I don't know much about Ercolania though, but I believe it is on the order of weeks and I don't believe many are lecithotrophic.

Some sacoglossans are indeed known to be able to subsist off of their sequestered chloroplasts for extended periods of time, but this is not universal. You may be thinking of some of the more extreme Elysia species. I don't believe Ercolania is known to last more than 2 weeks. Further, they're all in a state of suspended animation when they don't feed.