- Hi, guys and girls, I'm ReefMan,
and I wanted to give you an introduction
to small polyp stony corals,
the different kinds that you can get, some basic care,
and some information about them
so that you can make a more informed decision for your tank.
So as you may know, all living things are in kingdoms,
phylums, classes, subclasses, orders,
families, genus, and species.
So every living thing on the Earth
that's an animal is in Animalia.
That's the kingdom we're all in.
And then the phylum for things with stinging cells
like jellyfish, anemones, coral, is Cnidaria.
Then the class is Anthozoa.
That is all of the corals themselves,
but also sea anemones.
And it actually is any flower-like animal.
That's sort of what it means there.
Then Hexacorallia is after that,
and that is, sorry, it's a sixfold symmetry.
And if you look at polyps of coral, they're symmetrical.
That's where that comes in.
And then after that, you have Scleri, sorry, Scleractinia,
which is the stony corals
that we're going to talk about today.
So we'll start off with some beginner corals.
Some things that you might want to look for
if you're just starting out in SPS corals are
from the Pocilloporidae family.
Those are things like Bird's Nest corals,
Pocillopora corals.
Those are going to be a little bit more forgiving
in your tank.
Under Pocilloporidae, there are two genuses
that you can think about including in your tank,
especially as a beginner.
One, very similar to Pocilloporidae, we have Pocillopora.
Those are a group of 66 different species.
All of them form branching colonies.
And if you're looking at a random coral,
the distinguishing feature of a Pocillopora
is that the branching colony
has wart-like protuberances all over it.
So there will be little bumps all over the branches,
the individual branches.
Those don't necessarily contain what's called a corallite
or individual polyp, but it's just kind of a growth
on the surface of the skeleton of the coral.
That's a distinguishing feature of Pocillopora.
These all have immersed polyps,
which means that they don't have a raised corallite,
a piece of skeleton that contains the polyp.
And this overall surface, aside from those wart-like bumps,
is going to be smooth.
They like medium to high light and flow,
but they're very forgiving
and very fast-growing in your tank.
Pocillopora is one of the few kinds of coral
that will reproduce in your tank.
It can actually become a plague in your tank.
So they can do sexual reproduction in your tank,
which is rare for other stony corals,
but they can also do something called polyp bailout
where the individual polyps will pop out of the colony,
float around your tank, and then colonize somewhere else.
So you could end up with hundreds
of these things growing all over your tank.
The other genus in Pocilloporidae is Stylophora.
Now, these are very similar in structure
but don't have the bumps that Pocillopora has.
And they don't have axial corallites.
So they are going to be small polyps immersed
over the skeleton, no raised bumps on the skeleton.
There are 40 species of Stylophora.
Now, one distinguishing thing about coral
and how to identify it, there are things called axial polyps
which are polyps on the end of a branch.
And there are things called radial polyps,
or radial corallites, sorry.
Axial corallites and radial corallites.
They are all around the outside of the branches.
So you might think of a radial corallite
as being all the corallites around the branch of coral
and the axial corallite being the one at the end.
So Stylophora have all radial corallites,
no axial corallites, and smooth thin branches again,
not like the Pocillopora.
They like medium light and flow.
They're very forgiving,
but not quite as much as Pocillopora.
For whatever reason, I can't keep Stylophora in my tank.
They don't do well.
So hopefully they'll do better for you.
But they are one
of the more forgiving small polyp stony corals.
So moving on, we switch the family
and we go to the Acroporidae family.
That contains Montipora, Acropora, Anacropora,
those kinds of genuses.
So Montipora is going to be a little bit more forgiving
than the other Acroporidae corals.
There are 206 species of Montipora,
and they're identified as having no axial corallite,
but they have very small immersed radial corallites
all over them.
No raised bits of skeleton surrounding the polyp,
just smooth-skinned coral
with no axial corallite.
They're most commonly plating or encrusting.
And as with Acropora and all of these things,
in your tank they might extend their polyps during the day,
but in the wild, fish are gonna eat 'em during the day,
so they only would extend their polyps at night most often.
The polyps of Montipora are small
compared to other Acroporidae.
They're less than one millimeter across.
And they like low nutrient water with bright right,
or with (laughs) bright light,
and they're similar to Acropora in care.
Now, Montipora would be a good beginning Acroporidae coral.
As you move up and your skill becomes better,
if your Montipora are all doing really well,
then your Acropora will probably also do well.
So moving into more advanced species
or more advanced kinds of small polyp stony coral,
we have another Acroporidae, and this is Anacropora.
This only has 12 species,
and it is very similar to Acropora
except it doesn't have an axial corallite,
so no polyp at the end of the branch.
And it has very widely spaced radial corallites.
Anacropora has slender branches,
less than 10 millimeters thick,
so nothing very massive like a staghorn coral would have.
And they have blunt ends.
They don't have a pointy end the way a Stylophora would.
They have, as I mentioned,
widely spaced small protruding radial corallites.
So they're not smooth the way, say,
a Montipora digitata would be.
They would have bumps associated with every polyp.
And to distinguish them from Acropora,
Anacropora can handle a lot more nutrients in the water.
So if your tank has a lot of LPS,
things like that that like a lot of food,
you might consider Anacropora instead of Acropora,
because your tank probably has higher nutrients
for the LPS that you're keeping.
So that brings us to the last genus
that we'll cover in Anacroporidae, and that is Acropora.
There are 345 species of Acropora.
And if you just picture a coral reef in your mind,
what you're picturing right now is probably Acropora corals.
They are by far the most common
reef building coral out there,
and they're also the most common SPS coral
that you would get in your tank at home.
The distinguishing feature
of an Acropora coral is the axial corallite.
They are the only kind of coral
that actually has an axial corallite.
And, again, that's the polyp
at the end of a branch like you can see.
The axial corallite is often a bright color
and contrasts with the rest of the coral as well.
The way these things grow,
the axial corallite lays down skeleton around it.
And as it grows and protrudes from the colony,
radial corallites bud off from it
and start filling in the gaps.
There are densely packed radial corallites
all over the body of an Acropora coral.
And ever once in awhile,
one of those radial corallites becomes an axial corallite
and a new branch starts to grow.
As I mentioned, the corallites
on Acropora are densely packed.
They're not widely spaced like Anacropora.
And they're pretty big,
two to three millimeters across on average
with a corallite surrounding them
that's protruding from the skeleton
about two to three millimeters as well.
Acropora is the most demanding
of all these kinds of coral that we've covered.
They like very nutrients, water.
Some nutrients are important.
Some phosphate and nitrate is important
for their development, but in general, very low nutrient,
very high flow, very random flow with high light,
so over 150, 200 PAR or so
will do Acropora well.
All of these corals will do well being fed in your tank.
You might need to turn off the lights
and turn off your pumps and then target feed them things
like PolypLab coral food or other coral foods,
but they will all appreciate it.
They're all photosynthetic.
But, again, appreciate actual food every once in awhile
and will grow better for you if you do that.
So I hope this was interesting.
It'll give you an idea of what you're looking at
when you're considering buying a new coral online
or from a store, because they get names like Toxic Lemonade,
and who knows what that actually is?
But if you can look at the picture and decide,
oh, well, it has an axial corallite, so it's an Acropora,
you'll have a better idea of the care requirements
for that random coral that you're looking at buying online.
Getting down beyond just the genus is really difficult.
You're gonna have to get into the skeleton
and look at the actual shape of the corallites
and things like that,
not something that you're gonna be able to do
just from looking at the outside of the coral very easily.
So I wouldn't try to really nail down too much
at a species level, which is important of course for care,
but you can at least get an idea
just from knowing the genus.
So I hope this introduction to coral taxonomy
and identification was interesting.
Let me know in the comments what you thought.
Don't forget to subscribe, and I will see you next week.
Bye.