TOTM: Common Macro-algae

celacanthr

celacanthr

Active Member

Caulerpa
Caulerpa is probably the most commonly seen macro-algae, at least in my experience. It is sold under several names depending on the species.
C. prolifera-Caulerpa, Blade grass, Blade Algae, Blade Caulerpa, Razor Grass, Razor Caulerpa, etc.
C. racemosa/C. lentillifera-Sea grapes, Grape Caulerpa, Bubble Caulerpa, Bubble Algae (which is confusing because the bad algae, Valonia, is also called Bubble Algae), even Green Caviar, because of its use in Asian cuisine!
C. taxifolia/C. mexicana-Feather algae, Feather Caulerpa, Feather Grass.
Despite their only being 5 species commonly seen in the aquarium trade (many places WILL sell you several other species), there are over 100 species in the genus! The ways and shapes that they grow can be vastly different from 1 species to another.
In most Caulerpa, there are 3 parts, the stolon, the rhizoids, and the fronds.
Stolon-This is the "vine" looking growth that all of the fronds and rhizoids are attached to. The growing tip of the stolon is usually white in color.
Rhizoid- these act as the roots for the Caulerpa. Commonly called steadfasts, rhizoids can grip rock and sand particles surprisingly well, which can attribute to the fact that Caulerpa can be difficult to eradicate in a tank where rhizoids have gotten a good grip on the rock in the tank.
Fronds- this is the part of the Caulerpa that sticks out from the stolon and absorbs the majority of the nitrogen, phosphorous, carbon, and lighting that the Caulerpa needs. In Caulerpa prolifera, these are the blades.
Unfortunately Caulerpa's are notorious for "going sexual” like Halimeda. If you are lucky you may notice that your Caulerpa has numerous thin, white-ish clear stalks coming from them, these are called gametangia, and this is a sign that your Caulerpa is about to go sexual. If you notice this it is best to rip up almost all of your Caulerpa and throw it away. The part that you leave should be free from gametangia, and as an added measure it should be put in a separate container for a while (a day or more is probably best). The process for ridding your tank of the gametes is the same as with halimeda, discussed below.
All Caulerpa IME are great for nutrient export with at least one minor exception among the commonly sold Caulerpa's. C. paspaloides grows in a pattern where new fronds will spring up, and as they do the old ones will die off. Most likely the old rotting stalks will just add back any nitrogen that was used initially unless the aquarist removes the stalks before they rot. This is a great deal more work than is necessary for the other Caulerpa’s.
There is another Caulerpa that is not well suited to be owned by many hobbyists, but not because of its growth patterns. C. taxifolia has become an extremely invasive species around the world. California is one of those places where C. taxifolia has been introduced and is now taking over local waters. Unfortunately many people blame hobbyists for the introduction of this species, and whether or not these allegations are true, there is now a law banning C. taxifolia (maybe even all Caulerpa's, the law is confusing) from being owned in California, and there seems to be some people pushing for the ban to be extended to other states.
I do want to add a word here about using Caulerpa of any sort to feed herbivorous fish. It is ok to feed most Caulerpa's -such as C. prolifera-, but only in limited amounts. All Caulerpa's contain some toxin used to deter predators, but in the tropics most herbivorous fish have developed immunities to the toxins. Regardless I still would not feel safe feeding only Caulerpa to any herbivorous fish. On a side not these toxins are what have made C. taxifolia so successful in temperate waters, since the herbivores there have not developed any immunities to the C. taxifolia toxins.
Ulva: I add Ulva here because its care is almost identical to Caulerpa, except that it makes GREAT food for most herbivores, and is even used in soups and salads. Some of the 10 species in this genus are even used as a substitute for nori (Porphyra), an ingredient in sushi and commonly used for Herbivore food in marine tanks.
 
celacanthr

celacanthr

Active Member

Halimeda
Halimeda is in the same order as Caulerpa, but it is vastly different from Caulerpa. Halimeda is what called a "calcareous algae", because they use mostly calcium -instead of mostly nitrogen like most macros- to grow. Halimeda is commonly called the "money plant" because it looks like several (flimsy) green coins stuck together end-to-end.
These discs are mostly made up of calcium carbonate in the form of aragonite crystals. For the plant to grow it must expand its already existing discs, and add new discs, which it does by adding more calcium carbonate to the existing skeleton. Halimeda is capable of growing very rapidly, in fact it has been reported that Halimeda is in fact the primary tropical reef-building organism.
It's use of calcium carbonate skeletons makes it very unappetizing to grazers like surgeonfish, or rabbit fish, but Halimeda takes it a step further by producing 2 toxic compounds, halimedatrial and halimedatetraacetate. These compounds deter all but a very few specialized predators. One type of Halimeda predator, a species (or two) of sacoglossan slugs, is closely related to the hair algae (Bryopsis) eating lettuce "nudibranch".
Halimeda's use of calcium carbonate is very similar to the stony corals use of calcium carbonate. This means that Halimeda should be kept in an aquarium that has calcium and alkalinity at similar levels to a stony coral tanks levels.
The downside to Halimeda is that it too can release gametes into the water.
This process is commonly called "going sexual" in the hobby, and can prove disastrous and even deadly in our closed systems. Thankfully Halimeda gives a warning signal before it "goes sexual". Several hours before releasing its gametes into the water, Halimeda will move all of its chloroplasts into tiny dots revealing the very white calcium carbonate skeleton.
Soon after these green dots are formed, thousands of gametes may be released into the water turning the aquarium into a wonderful pea soup wonderland. YUCK! Each one of these gametes is, effectively, a tiny aerobic organism, and will therefore quickly use up most of the oxygen in the aquarium. You should immediately start aerating the aquarium by any means possible, which should prevent tank inhabitants from suffocating. Unfortunately after you are done worrying about your organisms being deprived of oxygen, you then have to worry about them dieing from those compounds that Halimeda use to deter predators. Although this is unlikely to be a serious problem, better safe than sorry. Some good skimmer action, and a few frequent water changes should quickly rid your tank of most or all of the gametes, without any lose due to toxins.
Halimeda does best if attached to a hard surface.
The best way to spread Halimeda is by either:
a) fragmenting it, and gluing the fragment to a rock, or other hard structure
b) placing the rock it is on near other rocks allowing the Halimeda to create new shoots onto the other rocks
Pine Cone, and Merman's Shaving Brush: Both of these need the same care as Halimeda, except that they do best if they are put into a sand bed, and they should not "go sexual". Given optimal conditions these will reproduce by sending up small shoots from the sand bed. These will often go into "shock", and drop all their bristles. Given the right conditions they will grow these back in a week or so.
 
celacanthr

celacanthr

Active Member
Chaetomorpha
In many way's Chaetomorpha is similar to Caulerpa:
They both grow rapidly
They both are extremely effective ways of reducing nitrates and phosphates
Both common in the hobby
But Chaetomorpha and Caulerpa are vastly different in the way that they grow, and on a cellular level. One plant of Caulerpa consists of one cell, several nuclei (which BTW means that some species of Caulerpa have the largest cells in the world), and different parts such as the stolon, fronds, and rhizoids (discussed earlier), whereas Chaetomorpha on the cellular is more complex consisting of thousands of cells, each with one or more nuclei all attached to each other in a long string, but in growth pattern Chaetomorpha is much simpler usually growing in long un-branched strings, giving it its common name "Spaghetti algae".
Because of this growth pattern hobbyists had to devise away to allow every strand of the Chaetomorpha (chaeto) access to the light, so that parts that were covered by other strands would not die off.
There are several ways of doing this:
Tumble method-In this method the idea is to get the flow in the container where the chaeto is kept to cause the chaeto to flip over and over allowing all sides of the chaeto access to the light and prevents detritus build up inside the chaeto. Very effective if done correctly, but often takes extra planning in the planning phase of the refugium or sump, and may mean that you will need extra powerheads.
Fluff method- In this method the idea is to on a regular basis take the chaeto and shake it and pull it apart a bit to allow all of the strands access to the light. This can be effective unless you have a large amount of detritus in your tank that gets trapped by the chaeto, because every time you shake the chaeto the detritus just re-enters the water column. There is a way around this by only shaking the chaeto when you do a water change, and only shake it in the water change water. More upkeep work, but may prove cheaper on the startup cost, and the chaeto acts as a mechanical filter trapping detritus in the water column much like a filter pad would.
Let it be-In this method you want to just let the chaeto sit in the sump or fuge and every time that you see a yellow, or decaying section you collect it and throw it away. Less effective than the other 2 methods, because the chaeto may not grow fast enough to keep up with the hobbyist.
If the chaeto begins to break into smaller peaces this may indicate that there are not enough nutrients in the tank to sustain the amount that is in the tank, and it may be best to remove a good amount of the chaeto to see if the tank will be able to sustain a smaller amount of the chaeto.
Gracilaria- Similar care to Chaetomorpha, except that it is slower growing and can have very amazing colors, like red or dark orange, but can also be found in brown. Also used as food for humans, and may be a good adition to a herbivores diet.
Other algae- There are other algae such as codium, dictyota, and thousands of others whhich are either rare, or used primarily as decorative algae, a topic that I would like to discuss later along with other topics such as nutrient dosing (dosing nitrates! :scared: ), and marine vascular plants.
All comments, questions and pictures are welcome.
 
celacanthr

celacanthr

Active Member
Originally Posted by Dogstar
What ! No Pictures...aaaahhh
Good job, nice post.
Nope no pics, because I don't have a very good camera, and I don't wanna deal with copyright stuff.
 
celacanthr

celacanthr

Active Member
Originally Posted by milomlo
Great post!

WooHoo

Thank you! And you were very "supportive" during the writing of it.
 
pyro

pyro

Active Member
I was wondering; I have had a couple different opinions on what i have in my tank. I'll take pictures of both types of algae and post them for refence. One looks like a long oval leaf thats been twisted a couple times and the other looks like a fern. Both grow pretty heavily with roots and spread with runners.
Nice post
 
celacanthr

celacanthr

Active Member
Originally Posted by Pyro
I was wondering; I have had a couple different opinions on what i have in my tank. I'll take pictures of both types of algae and post them for refence. One looks like a long oval leaf thats been twisted a couple times and the other looks like a fern. Both grow pretty heavily with roots and spread with runners.
Nice post
Ok, thanks! That would be great! I am just going to take a guess now for the heck of it and say that the oval leaf one is C. prolifera, but I have no idea what the fern one is.
 
You must log in or register to reply here.
Top