- Acropora-eating flatworms are never a nice surprise
to find amongst the branches of your acropora corals.
These tiny little brown flatworms,
leave characteristic round bite marks in the flesh
of the acropora that they're feeding on.
And they also leave tiny little egg clusters around the base
of those same corals.
There are dips and things like that,
that you could use to remove acropora-eating flatworms,
but you can't dip your entire tank and the adults.
Well, they're not always on the coral anyway.
Hi guys and girls,
I'm Reef Man.
And this video is all about Biological Controls
that you can use
to control acropora-eating flatworms in your tank.
If you're new to my channel,
then Hey, welcome and take a moment to subscribe
and you'll get more videos like this
but every week or so.
So there is a paper that just came out
from a team at the sea simulator in Australia
and it's titled Biological controls
to manage Acropora-eating flatworms in coral aquaculture.
In the paper,
the team is researching both the Six-Lined Wrasse
and the Peppermint Shrimp Lysmata vitta ta
to see how well they'll do at controlling both
the adult acropora-eating flatworms and their eggs.
There's a link down below in the description
and the paper is open access.
So check it out,
and you'll get all the details in way more
than I'm going to go into in this video.
I did another video a while ago,
which is all about the acropora-eating flatworm.
So if you want to learn more about the life cycle,
some tricks you can use
to control them without adding chemicals
or animals to your tank,
then check the video out it's linked above.
So what actually is a biological control?
You may not have heard that term before.
Simply put, it's finding and using an animal
or a parasite or bacteria or something
that naturally preys upon the thing
that you want to control.
Peppermint shrimp and Berghei and Nudibranch are used
to control Aiptasia and Anemones.
The threadfin butterfly fish
can help control a different nudibranch
that actually preys on our coral.
The acropora-eating flatworm does have natural predators.
However, this paper is the first to be published proving
that there are effective ways to control these pests.
Very little is actually known about the wild habits
of acropora-eating flatworms most of the knowledge
we have is from aquaculture.
Peppermint shrimp are used already in captivity
as cleaner shrimp,
they remove parasites from the fish
that are housed with them.
And there's some anecdotal evidence
that the Six-Lined Wrasse will
also eat acropora-eating flatworms.
But how effective are they really?
This team of researchers
purchased 20 vittata peppermint shrimp,
as well as 10 six-lined wrasse for their research.
The shrimp were all housed together
in just one 50 liter tank,
but since Six-Lined Wrasse are very territorial,
they were housed individually in 50 liter tanks.
They fed all these animals every day,
but they stopped feeding them 24 hours before
they ran their trials.
The experiments themselves measured the effect
that those animals would have on acropora-eating flatworms
and their eggs over that 24 hour period
that they were monitoring.
From seven parent colonies of acropora Millepora,
96 fragments were cut using bone cutters and a bandsaw.
These were all
then mounted on little frag plugs using superglue,
and that's what they used in the experiment,
to infest them with flatworms,
they took five adult acropora-eating flatworms,
and they placed them directly
onto the corals tissue before the start of each trial,
so five worms per frag of coral.
To test the egg capsules,
they took sections of coral skeleton
which contained the eggs they cut them off
and then glued those segments on to a frag plug.
The experiments themselves were conducted over four days,
with each individual day being a single set of trials.
Six tanks were set up each day along
with six control tanks
that wouldn't get the shrimp or the fish.
They left the animals in with the infested coral
for 24 hours,
and then they counted the remaining eggs
and the adult worms that were left in each tank
to compare to the number present before the trial started.
It's important to note
that peppermint shrimp actually don't eat at all
for 24 hours before or after a molt.
So they excluded animals that molted directly before
or during the study from the results
so that you wouldn't have a change result set.
The peppermint shrimp consumed
both adult flatworms and eggs,
significantly reducing the numbers of both.
In fact, about 82% of adult flatworms were eaten along
with about 63% of egg capsules.
Peppermint shrimp they don't find food using their eyes
like we do.
Instead, they rely on chemical cues
which they pick up from their antennae.
Because of this,
they actually have to physically come across a worm
or an egg cluster in order to find it and eat it.
And because of that peppermint shrimp might
not work very well in a large reef tank like mine,
they're just not gonna find the worms and eggs.
However, if you have a coral quarantine system,
they gonna work really well in something like that.
The six-lined wrasse were also very effective
at reducing the numbers
of adult acropora-eating flatworms with a 100%.
Every single one of those flat worms were eaten
by the six-lined wrasse.
However, the wrasse didn't need any eggs,
so they will only impact the population numbers
of flatworms in the adult phase of their lives.
Six-lined wrasse are very territorial fish,
so keep that in mind if you're thinking about adding one
to your tank.
Peppermint shrimp, on the other hand,
can be kept in a small colony a few animals just fine.
Adding both together is
also an option you have depending on
how big your tank is and
how concerned about acropora-eating flatworms you are.
This paper was really interesting.
It's linked down below.
It's really easy to read.
Check it out if you want to learn more.
And also, I strongly recommend being sure
that you actually want a peppermint shrimp before adding one
or more of them to your tank.
They can bother things like LPs corals,
chalices, things like that sometimes.
Similarly, be sure that you're ready
for the territorial nature of a six-line dress.
Once you've added one of those fast little fish,
you're not gonna be able
to easily get it out without destroying your tank.
I hope you enjoyed the video, stay safe.
Have a great day.
If you are battling acropora-eating flatworms
then hang in there.
Good luck and you gonna beat those little critters.
Just take some time and some effort.
I'll see you next time.
Bye.