Bulb Hypothesis for Bubble Tip Anemones

[atlantean]

Obviously, there are two ways an anemone can acquire nutrients: photosynthesis or catching prey. Longer tentacles seem more adaptive for catching prey, and inflated (bulbous) tentacles seem adaptive for photosynthesis (by increasing each tentacle's surface area and "stabilizing" the tentacles for more uninterrupted light exposure). An anemone could change moment to moment which form it adopts, but I would expect it to generally favor the method in which it would be more successful in acquiring nutrients in its environment.

Thus, I would expect an anemone conditioned to favor catching prey over photosynthesizing would display longer tentacles. In contrast, if an anemone receives enough light such that photosynthesizing is a reasonable energy source to prioritize, and it does not as readily obtain prey items, it would develop more bulbous tips to increase its ability to collect light.

So, if you think of a BTA as adopting one of two behavioral "modes" for nutrient acquisition, a lot of the associations of bulbous tips with particular environmental characteristics start to make sense.

Let's discuss! How often do you feed your anemone and what amount of light is it receiving? My prediction is that a regularly fed anemone (2x per week) would be less likely to have bulbous tips even under high light conditions.

 

[xxkenny90xx]

That's a solid theory. But I rarely feed my nems (once a monthish plus whatever they catch when I feed the fish) and some are bubbled, some have stringy tentacles...

 

[atlantean]

That's a solid theory. But I rarely feed my nems (once a monthish plus whatever they catch when I feed the fish) and some are bubbled, some have stringy tentacles...

It seems like it's also typical for larger nems to be more "stringy." Is that the case in your tank? Perhaps larger ones develop enough surface area such that bubbled tips no longer offer much benefit?

 

[xxkenny90xx]

It seems like it's also typical for larger nems to be more "stringy." Is that the case in your tank? Perhaps larger ones develop enough surface area such that bubbled tips no longer offer much benefit?

For this cluster, yes that seems true. I do also have a smaller green bta with stringy tentacles but it is in a different part of the tank so it get different flow and lighting then the rest.

 

[Spare time]

Analogously, clones of small individuals of E. quadricolor allow occupation by large numbers of demonstrably protective fish. In addition to the effects of fish upon hosts described above, the tentacles of this anemone develop a distal bulge within minutes of a fish's entering the anemone, as first noted by de Crespigny (1869); without fish, the tentacles generally lack bulbs (Dunn, 1981). This response may serve to expose more surface area to sunlight ( as occurs with zooxanthellae-packed pseudotentacles of certain actinians ( e.g. Lewis, 1974) and corals ( e.g. Fricke and Vareschi, 1982 ). A functional hypothesis for this reaction and for the greater expansion of anemones in the presence of fish than in their absence ( see above) that can be tested is that zooxanthellae are better able to make use of energy ( C) in the presence of a source of nutrients (N, S, P, etc.) than they are in its absence.

Fautin (1991) The Anemonefish Symbiosis: What is Known and What is Not

https://dalspace.library.dal.ca/bitstream/handle/10222/77098/VOLUME%2010-NUMBERS%201,2,3-1991-PAGE%2023.pdf?sequence=1

 

[xxkenny90xx]

Analogously, clones of small individuals of E. quadricolor allow occupation by large numbers of demonstrably protective fish. In addition to the effects of fish upon hosts described above, the tentacles of this anemone develop a distal bulge within minutes of a fish's entering the anemone, as first noted by de Crespigny (1869); without fish, the tentacles generally lack bulbs (Dunn, 1981). This response may serve to expose more surface area to sunlight ( as occurs with zooxanthellae-packed pseudotentacles of certain actinians ( e.g. Lewis, 1974) and corals ( e.g. Fricke and Vareschi, 1982 ). A functional hypothesis for this reaction and for the greater expansion of anemones in the presence of fish than in their absence ( see above) that can be tested is that zooxanthellae are better able to make use of energy ( C) in the presence of a source of nutrients (N, S, P, etc.) than they are in its absence.

Fautin (1991) The Anemonefish Symbiosis: What is Known and What is Not

https://dalspace.library.dal.ca/bitstream/handle/10222/77098/VOLUME%2010-NUMBERS%201,2,3-1991-PAGE%2023.pdf?sequence=1

This seems like the opposite of what I see in my tank. Check out the picture above. My clowns only hang out in the big nem with the stringy tentacles

 

[Mellotang]

i think It is more to do With flow

these are in very little flow

no fish hosting in them either

 

[Mellotang]

same anemones

high flow

hosting these clowns

 

[drewwCh]

Fully agree with your hypothesis.

My nem used to be very bubbly and stretched out when lighting and flow were lower. Now that I've increased both, it seems to not expand its body so much and it has changed its bubbly tentacles to a more stringy type.

I think with added flow, more food is able to get to the nem, and with stronger lighting, there's no need to bubble up the tentacles to get more light, thus its longer and skinnier tentacles.

Despite this though, sometimes only some tentacles will become stringy, while the others remain bubbly. Other times, the nem will have all its tentacles stringy, but later in the day have them bubbly which is really confusing to me.

Anyway, nice theory!

 

[atlantean]

Fully agree with your hypothesis.

My nem used to be very bubbly and stretched out when lighting and flow were lower. Now that I've increased both, it seems to not expand its body so much and it has changed its bubbly tentacles to a more stringy type.

I think with added flow, more food is able to get to the nem, and with stronger lighting, there's no need to bubble up the tentacles to get more light, thus its longer and skinnier tentacles.

Despite this though, sometimes only some tentacles will become stringy, while the others remain bubbly. Other times, the nem will have all its tentacles stringy, but later in the day have them bubbly which is really confusing to me.

Anyway, nice theory!

Yes, I had similar thoughts about the flow. In low flow an anemone is probably much less likely to catch food, even more so if they're small, young nems.

I don't think we'll be able to understand some of the weird hour to hour changes, but worth thinking about why they may stop forming bulbs. Some of these things we can control, but it will also depend on where they set up shop.

 

[Spare time]

This seems like the opposite of what I see in my tank. Check out the picture above. My clowns only hang out in the big nem with the stringy tentacles

It says they may possible expand with the presence of fish as the zoozanthellae are not as limited by C, N, and P when fish are there to help provide them. Longer tentacle means more surface area for zooxanthellae for photosynthesis.

 

[Mellotang]

Maybe KH plays a roll Too

In the pic with the bulbs the Kh is 7 dKH

in the stretched out polyp picture the dKh is 10

 

[atlantean]

It says they may possible expand with the presence of fish as the zoozanthellae are not as limited by C, N, and P when fish are there to help provide them. Longer tentacle means more surface area for zooxanthellae for photosynthesis.

In our tanks, nitrogen and phosphate are typically higher than in natural sea water so I don't think the lack of bulbs is related to C, N, P limitations. Also, they state that bulbs develop within minutes of fish entering the anemone. How are the zooxanthellae suddenly no longer C, N, and P limited in such a short amount of time?

I think it's worth starting with the question of why these bulbs would be evolutionary useful in the first place. If longer tentacles are better for catching prey and for photosynthesizing, why would they have ever evolved these bulbs?

 

[Chessmanmark]

Mike Paletta has a video that addresses this.

He has some RBTAs in high light that have nice bulbous tips.

He also has the same RBTA in a shaded area. These anemones don’t have bubble tips, but are longer.

He says intense light will give you the nice tips.

That being said, I was given a RBTA that never had fat tips.
It sat under a 250 w MH in a LumenBright and split multiple time,
but never had those tips.

 

[flying4fish]

Interesting thread, but it seems we are right back where we started: clueless as to why BTA's bubble or don't bubble. I introduced a small Black Widow BTA to my small reef tank 3 years ago. A bit more than a year ago it spontaneously exhibited bubbles for maybe a week or so, without any changes whatsoever, but then stretched out again. It has hosted a clownfish for the duration. It has lots of light and moderate flow. It has gotten so big (14-18" wide) that it has wiped out an entire corner of my display! I wish I could command it to behave and exhibit bubble tips, but alas, it doesn't listen. I recently spent 2 weeks torturing it to move to where I could peel up the foot...then I cut it in half...now I've got two of the little monsters that I'm going to trade to someone with a bigger tank. Another interesting tidbit (not related to bubbles), my clownfish had been looking horrible, milky skin and ratty fins. Once I removed the BTA it healed right up and now looks gorgeous. Apparently not all clownfish are 100% compatible with BTAs.

 

[Lovefish77]

Based on my humble opinion (i only owned black widows), a perfectly healthy anemone in a thriving environment SHOULD NOT bubble in spite of its name sake. Anemones bubble, based on what i experience, when given very little flow and very low light (inadequate light). This ties back to your theory that they bubble to possible get more light to convert energy and grow. All anemones i have seen doing well have very long strings tentacles. I think people get anemones and try to accommodate them in a mixed reef tank and therefore giving them light intensity that is less than ideal. I give my black widows like 420-450 par and they seem to be hungry for more and they never go down in the rock work. The only time i see them partially bubble is before the light turns on (proving my theory).
One great thing about anemones is that they have their own par meter and they can move, so you cannot over-light them in that sense, but i think a lot of people underlight them that is why you end up with pale colors for the tentacles.
that is just my 0.02 and what i have seen personally.

 

[Lovefish77]

i think It is more to do With flow

these are in very little flow

no fish hosting in them either

I know this is just my theory, but how much light are these nems getting (par wise)? The tentacles almost look translucent possible because of not getting enough light. When my black widow splits and one end up hiding under the island due to lack of real estate, when it emerges it has those washed out colors. But given a week basking in intense light the colors go back to normal. For instance, in some of the tentacles in your image, i can see the tentacle behind it through the tentacle in the front. This rules out the possibility of this being an under exposed image.

 

[Lovefish77]

Maybe KH plays a roll Too

In the pic with the bulbs the Kh is 7 dKH

in the stretched out polyp picture the dKh is 10

That could be it. But in the past few months i have been playing with alk a LOT with no visible effect to my black widows AT ALL.
In my 75g i keep alk at 7ish and have been raising it gradually to 9dkh (just tested today).
In my 20 cube where i only keep black widows, i did not do water changes until alk slid down to 5.2 dkh. I lost a couple of SPS and nothing whatsoever happened to my black widows. Since then over the course of three weeks or so i raised alk to 9 dkh with no effect whatsoever on how anemones looked. That is why i love anemones because they are so forgiving.

 

[Alexreefer]

Hmm very interesting, I have a rbta that sits almost on the sand in my 75G. it has long stringy tips while before it moved it has bulbs when it was more than halfway up the tank

 

[atlantean]

Based on my humble opinion (i only owned black widows), a perfectly healthy anemone in a thriving environment SHOULD NOT bubble in spite of its name sake. Anemones bubble, based on what i experience, when given very little flow and very low light (inadequate light). This ties back to your theory that they bubble to possible get more light to convert energy and grow. All anemones i have seen doing well have very long strings tentacles. I think people get anemones and try to accommodate them in a mixed reef tank and therefore giving them light intensity that is less than ideal. I give my black widows like 420-450 par and they seem to be hungry for more and they never go down in the rock work. The only time i see them partially bubble is before the light turns on (proving my theory).
One great thing about anemones is that they have their own par meter and they can move, so you cannot over-light them in that sense, but i think a lot of people underlight them that is why you end up with pale colors for the tentacles.
that is just my 0.02 and what i have seen personally.

Yes! I finally feel understood. However, I think a desperate nem that is in low light though may still get stringy to increase its chance of catching food. I almost always see BTAs bubble up in shops. They're usually small in size, their light is probably usually moderate (they're not kept in the SPS tanks), and I doubt staff feed them, so naturally they're going to try and make themselves bigger.

Assuming an anemone has spent a reasonable enough time in these parameters, here is what I'm trying to communicate. In particular, I think the effects of frequent feeding will occur slowly.

Overall size of the anemone is going to also dictate the amount of light it is collecting. The anemone does not have a brain, but these are the environmental conditions that I think would trigger it to express the bulbous trait.