Algal genus Spotlight: Bryopsis "hair algae"

[horge]

This was originally going to be submitted to Reefkeeping way back in July. For various reasons I didn’t think it would fit in, and decided my energies better focused on the tedious grind of filling out the online MaBMA (marine benthic macroalgae) catalogue.

I will be posting genus-level articles on TRT and here on RC every couple of weeks, in the hope that readers will contribute their photos of the alga being discussed, as well as contributing their experiences with the same. What follows is a slightly condensed version for RC, the lengthier original remaining on TRT’s forum, angling for the photos and experiences of interested readers, who have also been pointed to this forum.

Whatever the TOS on this board, the article and its excerpts remain my intellectual property. Enjoy.



*****
TRT MaBMA Algal Spotlight
“Hair Algae� Part 1/10 : Bryopsis
Author: Horge Cortes Jorge Jr.

Introduction
One of the most beloved of macroalgae in reef aquaristics are those rare guests, Bryopsis, one of several genera affectionately dubbed ‘hair algae’. Bryopsis are a vital and much sought-after component of the compleat reef aquarium. Bryopsis can cure cancer, end poverty, and bring about world peace.

But enough sarcasm.
The marine green algae Bryopsis are, to my perception, the most prevalent and problematic sort of ‘hair alga’ around our hobby, colonizing and dominating captive reefscapes with a speed and remorselessness that would make a Spanish conquistador blink.

Why are Bryopsis so common? Why do they spread so fast?
What does one do to rid one’s aquarium of them?
Why not read on, gentle readers?


Taxonomic Background
There are at least 50 species of Bryopsis (including varieties and forms), but only a mere seven species are commonly found in tropical waters, plus three varieties of one of the most commonly cited species:

Bryopsis corticulans
Bryopsis corymbosa
Bryopsis halliae
Bryopsis hypnoides
Bryopsis indica
Bryopsis pennata
(Bryopsis pennata var. leprieurii )
(Bryopsis pennata var. secundata)
(Bryopsis pennata var. secunda)
Bryopsis plumosa
Bryopsis ramulosa

Many of the diagnostics between these species can be subtle to a hobbyist, and furthermore the morphological variance within some species (take just the much-cited B. plumosa for example) can be surprising. It is often practical not to differentiate between them.
What use, then, the list above?
I just wanna name-drop.


God willing, MaBMA will deal with the dirty details of species-level diagnostics.

Morphology & Reproduction
Bryopsis all go through two alternating phases that are starkly different in appearance: as gametophytes and as sporophytes.


Fig 1.1: The gametophyte phase of Bryopsis, likely Bryopsis corticulans, producing male and female gametes which combine to form a zygote, which in turn settles to form the other phase, called a sporophyte:


Fig 1.2: Bryopsis sporophyte is a sometimes lighter-green, filamentous, sparsely-branching and ground-hugging little wretch.
(Cut me slack: a sketch is all I can muster right now. Give me your photos!!! )

Because Bryopsis gametophytes are monoecious, they would seem to value sexual quantity over quality: during sexual reproduction, the chances are very good indeed for girl gametes and boy gametes to meet up and do their thing since they can come from so close to each other --as in, the same algal specimen. This means that ‘self-fertilization’ is likely, and whatever benefit derives from a more catholic genetic lottery are largely lost to any population of Bryopsis.

We must note: that the resulting sporophyte phase (see Fig 1.2 again) is rarely reported in marine aquaria suggests that sexual reproduction is not the usual means by which Bryopsis multiply in aquaria. Also, if there really aren’t any sporophytes, then spore-based reproduction can’t be common in aquaria either. There may be under-reportage involved, but let's just suppose here AREN'T many sporophytes around: how might Bryopsis usually reproduce?

Reef aquarium enthusiasts ought to be familiar with reproduction via fragmentation, and Bryopsis are, by the way, coenocytic –meaning each thallus is technically a single, if multinucleate, cell. Any scrap of Bryopsis --no matter how small-- can regenerate if allowed to settle in a favorable location.

Alas, there’s more:
The gametophyte also reproduces by forming what are called microthalli on the ends of the pinnules, when it isn’t Bryopsis “breeding season� --we did earlier indicate that gametangia and gametes were formed seasonally, yes?. Anyway, each microthallus eventually detaches and drifts freely in the current, just waiting for the right surface to crash into and colonize, as sporophytes. Again, since not too many sporophytes are being reported, then microthalli-formation may not be a serious issue in aquaria, so we’re back to accusing fragmentation as the chief means of reproduction.

In case this reproductive picture has become too contorted for words (and considering the verbal diarrhea preceding, it ought to be), let me share yet another visual crutch to enhance our confusion (see Fig 1.3)


Fig 1.3: Bryopsis Life-Cycle
(Again, cut me some slack: a sketch is the best I can offer right now)

One more time:
Given a paucity of reported sporophytes, we might assume that reproduction via fragmentation is the primary route to Bryopsis' frequent dominance in a marine aquarium. (Or, again, maybe no one is paying attention to the little creeps, leading to severe under-reportage.)

Controls
As I mentioned in another article, the standard threefold plan of attack against a problem alga is as follows:

1. Manual removal of the problem alga
2. Suppression via appropriate herbivores
3. Denial of resources

Given the strength in Bryopsis’ ability to reproduce, there must be an emphasized fourth:

4. Severe curtailment of reproduction

Manual removal of Bryopsis is a tedious task.
The removal itself is easy, as the thalli are small and soft enough to be scraped off. The thallus however is susceptible to severe fragmentation. The challenge is in ensuring that no viable algal material is released into the display environment.

If manual removal is to be attempted in the display, a siphon is most useful for drawing off any fragments that may eventually settle and regenerate, pointed right where the action is taking place. The drawn-off water may be discarded, though I have sometimes filtered such wastewater through calcium hydrochloride powder–which apparently destroys algal cells, and stored the filtrate in bottles for later use as calcium boosters.

If the Bryopsis-infested rock (or other material) can be removed to a separate container for a scrub-down, so much the better. Whatever saltwater was used in that container, during scrub-down, and for the final rinses, should be discarded

More herbivores can adapt to eating Bryopsis than the many horror stories around might suggest. The most reliable are perhaps some sacoglossan slugs (of Genus Elysia, for example) which unfortunately have relatively short lifespans. Other effective herbivores include certain sea urchins. While the commonly-sold herbivorous snails can infrequently take a bite out of Bryopsis, they can be messy eaters and none too thorough, just as many herbivorous fish can be. The viable algal crumbs from their feasting make the problem worse.

Even with herbivorous pressure, there is also the problem of incomplete digestion to consider: viable algal material is often found in the feces of many of these herbivores, and a biodiverse ecosystem, with herbivorous/omnivorous scavengers and recyclers of all sizes (the sort that live on eating the crap of higher herbivores....yechhh), seems the best way to deal with it.

Denying Bryopsis the resources they need (particularly nutrient) is a tricky thing to attempt. Their magnificent, plumose arrays (in the gametophyte phase) spell efficient assimilation of nutrient in the water, likely far more efficiently than anything a rival “scrubber� algae can muster. No harm in trying to introduce competition, though! Obviously, one can try to limit the nutrients imported into the system. A reef aquarium must be fed, and natural, live foods can live on in the display, rather than decomposing and releasing nutrient when left uneaten.

Physical removal can become a repetitious ordeal even with the best efforts at providing herbivorous pressure and at denying resources to the problem alga(e). This is likely because of the impressive reproductive potential that Bryopsis own. The process of obtaining relief can perhaps be speeded up by specifically targeting the avenues that Bryopsis employ to perpetuate their presence. All aforementioned modes of Bryopsis reproduction depend on using the water as a transport medium, and water is among the easiest of a reef aquarium’s components to police, given the circulation systems we use.

A properly-designed UV sterilizer may effect a significant reduction in repeat manifestations of Bryopsis, within the context of physical removal, herbivorous suppression, and resource denial. Those latter three primarily deal with the presence of Bryopsis on substrate, whilst proper application of UV (or other prophylactic filtration) helps deal with the problem’s presence in the water, obliterating many spores, gametes, microthalli and viable fragments. It is also no small benefit that proper use of UV filters also provides rapid oxidation of many dissolved nutrients in the water, reducing one fuel that powers Bryopsis blooms.
Fourfold approach, then.

Of course, patience, humble perseverance and a little prayer go a long way. So does sharing your pain with your brothers and sisters on TRT (and RC).


Summary
Bryopsis are a formidable bunch of algae to deal with, and in no small part due to their reproductive prowess. They can reproduce sexually via gametes, or asexually via spores, fragmentation or dispersal of 'microthalli'.

Bryopsis are often deemed problem algae in the hobbyist reef aquarium. While addressing the physical presence with manual removal and herbivores, and attempting to slow its growth via denial of resources are important, it is likely just as important to restrict reproduction. Prophylactic filtration of the water (for example, via UV devices) may provide the means towards a shortened effort at controlling any outbreak of Bryopsis.


*****
Please help me:
Contribute your own photos of Bryopsis, and your experiences in dealing with it, what worked and what didn’t, to MaBMA. Post them on this thread and indicate your willingness to let me use them. If the kind of photo you post is just what I don’t already have, I’ll PM you for details (like what name you want to appear on the photo as credit, like in Jim Bednar's photo above, etc.)

After ten genera of hair algae, (every couple of weeks) I’ll move on to finger algae, I guess. Or maybe we'll do random Genera from all across the spectrum of weeds. Lemme know.


Yebaaa,
horge

[piercho]

Super! Just when i was going to start a whining thread about how boring it is getting on the plant forum, too. I apologize, I unfortunately haven't acquired that particular beauty for photos, so I have none to offer. Just wanted to offer thanks and some positive feedback for your efforts.

[horge]

Glad you like it, piercho

*****

Bill? Any moderator or adminsitrator?
Can someone please edit a typo in the above article?
In the preamble, I misspell the word slightly as 'sightly'
(as in "What follows is a sightly condensed version for RC...")

*****

Crossing my fingers for photos,
horge

[billsreef]

No problem

Had some lush Bryopsis in one of my fuge's, I'll check to see if I have any respectable photo's that included it. It crashed several months ago. I'd like to think due to superior nutrient control via, caulerpa and sea grasses

[Will]

Horge, PM me your e-mail address. I can send you more pictures of Bryopsis than you'll ever want. Heck, I can even send ya plenty of live samples!! This stuff is killing me! It even grows on other algae!!!!! Excellent article, by the way!
-Will

[horge]

It is horge, followed by @, followed by hotmail.
I am phrasing that way to foil mailbots

Can't you just post them here?
More fun for everyone that way!

[Will]

Alas, I didn't even think about that. I'll go get a few shots now and post in a few minutes.
-Will

[cal3v]

Wow I had some unidentified algae and it was bryopsis, I am gonna yank the tiny piece out.

[dc]

Well it's real hard to get a good picture but here's mine. I've been battling it for 8 months now. Ever since my tank overheated. I have bought a Foxface, Lettuce Nudibranchs, and Astrea snails. I also manually remove. I have less than I use to but it is still a battle. Yes if the pics are good enough you can use them.



An older picture, where it looks more like hair algae from far away.

[Will]

Debi, I think that's the same species that I've got. It's terrible stuff, eh!? I hate it!
-Will

[horge]

Debi, thanks.
Can you PM me the credit you want to appear on the photo, if any?

It may be a month or so before it gets used, though.

[johnrags1234]

Bryopsis is the devil! My patches did die however when I had lights off of the tank for 3-4 days. They just cam back, but I maually removed most of it.

John

[TheMandarinFish]

To beat hair algae, which I am currently in heavy combat against, I have read a *LOT* and experienced that, to beat it, you must:

1) reduce nutrients... the better skimmer you have, the less you will have. Think the largest EuroReef you can fit and afford

2) reduce phosphates... get phosphate sponge material, I think Kent makes good stuff. Run it through a cannister if you can (my next step, currently I have it in my sump in high-volume area contained in a nylon bag)

3) get an algae / lawnmower blenny... mine is obese. I'm not kidding. I think I am abusing the poor fish; he has a huuuuge gut.

4) get a zebrasoma tang... my purple and yellow and even hippo tangs go to town on this crap algae

5) set up a refugium... the more algaes that compete with hair algae, the better. Not just the coralline, but get gracilaria, sargassum, ulva, some mangrove trees, basically anything that will try to out-grow the hair algae by using the same nutrients, minerals, elements.

I used to have a veritable kelp forest of hair algae. It is at about 30% of what it once was just a month ago, and I hardly bother to remove it by hand.

Kicking off your lights won't eliminate it. Zapping phosphates, having plants compete with it, and having animals eat it will. Good luck!

[Will]

But my friend, Bryopsis is not hair algae. It truly is the devil! EVIL stuff!
-Will

[Jamesurq]

Originally posted by TheMandarinFish
To beat hair algae, which I am currently in heavy combat against, I have read a *LOT* and experienced that, to beat it, you must:

1) reduce nutrients... the better skimmer you have, the less you will have. Think the largest EuroReef you can fit and afford

2) reduce phosphates... get phosphate sponge material, I think Kent makes good stuff. Run it through a cannister if you can (my next step, currently I have it in my sump in high-volume area contained in a nylon bag)

3) get an algae / lawnmower blenny... mine is obese. I'm not kidding. I think I am abusing the poor fish; he has a huuuuge gut.

4) get a zebrasoma tang... my purple and yellow and even hippo tangs go to town on this crap algae

5) set up a refugium... the more algaes that compete with hair algae, the better. Not just the coralline, but get gracilaria, sargassum, ulva, some mangrove trees, basically anything that will try to out-grow the hair algae by using the same nutrients, minerals, elements.

I used to have a veritable kelp forest of hair algae. It is at about 30% of what it once was just a month ago, and I hardly bother to remove it by hand.

Kicking off your lights won't eliminate it. Zapping phosphates, having plants compete with it, and having animals eat it will. Good luck!

Tried them all - I guess I'm buying some lettuce nudis?

[ReefSpy]

Did someone say they wanted pics of hair algae?

[ReefSpy]

Here's another. I'll get some macros in daylight

[TheMandarinFish]

Euroreef, less feeding, phosphate sponge, and a refugium, along with my tangs and algae blenny have decimated the hair algae that was overwhelming my tank.

Now if I can just get rid of the crazap on the glass.

[Boomer]

Very nice piece Horge, so when can we expect a book . By the way, I just read your garlic piece, also nicely done

[dc]

No more pics? Well here's a before and after (sort of) These are the same corals also!

Oct 2002



July 2003

[Reefrunner262]

Lettuce Sea Slugs eat that stuff exculsivly, at least from what i have read.

PS good job DC!

Hope helps
Travis

[Los]

I was getting overrun with the stuff in my 240. Hated it and worse... my wife was starting to get annoyed.

Without knowing how much it would help, I bought a single lawnmower blenny and that damn bastard eats the stuff to quickly. Now I've only got a little tiny tuft left and I moved it to my quaranteen tank, since I actually like having a little bit of it around.

Those lawnmower blennies are NUTS. He single handedly, somehow, devoured about a shotglass sized chunk of algea per day.

Just my experience, and I'm not certain that it was the same type of algea, but it certainly worked in my case.

BTW, my algea had a single stock in the middle, with feathery looking strands going out the side. It actually looks OK when there is a little bit of it, but in bulk it was horrible. It would even start clogging my overflows.

Best of luck,

LOS

[lesd]

The vast majority of fish will ignore Bryopsis. I have Tangs who devour normal hair algae and caulerpa, but won't touch Bryopsis.

Some people have had success with rabbitfish. I've heard better stories about orange-spotted and doliatus rabbitfish than the common foxface. However, even that is hit or miss.

My problem is that I can't even use Lettuce slugs. I have too much flow in my tank and they just end up getting blown around and sucked into the overflow.

Phosphate removers (aluminum based ones) really make my leather corals unhappy.

So right now I'm just manually removing as much Bryopsis as I can, and it's steadily spreading all throughout my tank. Hopefully when I move the tank next month I can scrub down all the rocks and make a real dent in it.

Anybody tried a plethora of tuxedo or other urchins?

-- Lesd

[piercho]

My tuxedo seems to be mostly interested in coraline. It also does a fair job keeping red turf timmed back, but only if its very short and sparse. I suspect it is going through the red turf to get to the coraline. It won't go for fleshy algaes, at all, and doesn't do much to green turf (Derbesia?).

I've heard that diadema (long-spined) urchins will mow through just about anything they encounter, but I've never kept one myself.

[horge]

Originally posted by Reefrunner262
Lettuce Sea Slugs eat that stuff exculsivly, at least from what i have read.

Travis

Hi Travis
What you've read is much repeated myth.

When everyone started sharing online heartaches about Bryopsis, some entrepreneur must have skimmed through the internet to find a suitably-marketable herbivore.

The sacoglossan "lettuce" slug Elysia crispata (formerly Tridachia crispata) must have come up in searches because of a published study on its juvenile dietary preferences by Clark & Bussaca (1978). The study listed Bryopsis plumosa among the algae that the juveniles chowed on. Batophora oerstedi, Halimeda spp, Penicillus spp, Caulerpa paspaloides and Caulerpa racemosa filled out the rest of the menu in the locality they studied.

Somehow, Clark & Bussaca's "will eat Bryopsis"
got twisted into "will eat Bryopsis exclusively"

Jensen & Clark (1983) even showed that Caulerpa verticillata beat out Bryopsis for food preference among the lettuce-slug juvies.


Lesd et al.
Hi
The chief means towards Bryopsis spread in aquaria apparently remains fragmentation. Physical removal HAS to be accompanied by efforts to trap all algal debris generated by trimming/scraping.

If you're scraping in-tank, you'd better have a running siphon on-site to draw off viable algal debris. The siphoned-out water can be discarded, or else fine-filtered and then used for preparing kalkwasser (the high pH nukes algal debris to hell, and helps lock down any released organics) for later use. All precipitate is thus better discarded and NOT introduced t the display: just the clear-ish kalk fluid, thank you.

If you're scrubbing LR down in a basin somewhere else, the rock has to be rinsed thoroughly with saltwater prior to reunion with the diplay. The rinsewater is best discarded.

Systems with a UV filter and very good throughput have a noticably easier time controlling Bryo outbreaks ---the UV oxidizes a lot of waterborne nutrient, and kills waterborne (and viable) algal debris.


hth.
I'll post an article on another algal Genus one of these days.