Majano Anemone: Anemonia majano or Anemonia manjano

Phylum: Class: Order: Family: Genus: Species:
Cnidaria Anthozoa Actiniaria Actiniidae Anemonia A. majano or A. manjano

Majano anemones, sometimes also written as Manjano anemones are small light brown in color with light brown or green colored tentacles.  They may sometimes be semi-transparent (translucent).  The adult anemones typically have a relatively short stalk less than 1/2″ in length with short tentacles that are usually less than 1/4″ long.  The tentacles typically have bubble tips though not always.  The overall body diameter is usually under 1 1/2″ across though there have been reports of much larger specimens perhaps due to an incorrect ID.  Majano anemones are not well described in scientific literature, so it tends to be used as a catchall name for any small invasive anemone species that isn’t Aiptasia.

They are photosynthetic, but will also eat meaty things that are small enough for them to catch.  Like all anemones, their tentacles contain stinging cells to stun and capture prey and to wage war when necessary on neighboring invertebrates. The stalk is always attached to a hard substrate.

Majano anemones reproduce through the process of splitting and reportedly by the release of spores.  This allows the Majano anemone to reproduce quite rapidly.

Majano anemones may be confused with Aiptasia anemones, but the Aiptasia has much longer and slender tentacles.  Aiptasia are also always a translucent brown color while Majano most often have a green coloration.

 Open Aiptasia Anemone Database Entry 


Good or Bad?
Majano anemones are BAD!  A couple of anemones are not a big deal and can actually be quite pretty but the issue is that they can quickly spread.  They pack a powerful sting that can irritate or kill desirable corals and clams in the tank.  Majano are not as commonly seen in the hobby as Aiptasia, but have a similar habit of overrunning a tank if they are not controlled.   The important thing is to deal with Majano when you first recognize them in the tank.  They can reproduce quite rapidly and as their population increases, it becomes harder to eradicate them.  Since they can be quite attractive and not quite as invasive as Aiptasia, some aquarist will isolate them to a rock on the sand which will generally keep them contained if they don’t want to kill them.

What Do You Do?
Majano are most easily controlled when first observed in the tank.   Over time, if they are left unattended they will spread and make eradication harder.  New live rock and corals should be inspected before placing in the tank though it can be very difficult to spot the small Majanos, so this only gets you so far.   Unlike Aiptasia, there are no known good biological controls for Majanos, so control typically takes one of two main forms:

1) Mechanical Removal – The anemone is assaulted with brute force.  Unlike Aiptasia which can regrow from small bits and thus precludes this approach, Majano do not have this capability, so mechanical removal can be tried.  The anemone can sometimes be grabbed with forceps or tweezers and pulled off the rock.  If the rock is removed from the water, ice or other irritant can be applied to help get it to release it’s foot hold on the rock.

2) Chemical Control – The anemone is assaulted with an injection, feeding or slathering of something that will cause it’s death.

  • Inject with a store bought product.  There are products on the markets such as Aiptasia Stop which is a concoction of pepper juice that when injected into the anemone using a syringe, rapidly kills it.  I have used this product on Aiptasia and should work OK on Majano as well.  It is stated to be safe to other tank inhabitants and I have used it around clams, corals, etc. without any harm being done so their claims seem to have merit.
  • Feed it something toxic.  Joe’s Juice is a store bought mixture that is fed to the anemone and subsequently kills it.  Though I haven’t tried it, I have heard good results with this product.  Another similar product is Aiptasia-X.
  • Inject or slather it with a homemade caustic solution made from a concentrated Kalk solution or similar.
  • Inject with hot (near boiling) water.
  • Inject with lemon juice, vinegar or similar.

Unlike Aiptasia which can retract quickly, the Majano anemone is generally easier to use the injection method on.  I have used the method of injecting the anemones with vinegar while still in the tank and that has worked well for me.  After injection, the anemone quickly dies.  Vinegar in small doses is safe for the tank.  Large doses can lower the pH some but shouldn’t be an issue if you are just going after a few anemones.  The basic technique is demonstrated below, though I am using an excessively large needle in these pictures.  The small syringes that come with some test kits can work well for this purpose.


Majano Preinjection

You Can Run, But You Can’t Hide

Majano euthenasia

Injecting Vinegar

3) Death by Hydrogen– I should probably mention that a 3rd option exists.  Some enterprising individual has developed something called the ‘Majano Wand’ that can be used to kill Majano anemones that works equally well on Aiptasia anemones.  The device is an electric wand that uses a low voltage electrical current to create hydrogen gas from the saltwater.  Since anemones are largely composed of saltwater, this basically causes the anemone to explode from within.  Though not a low cost solution, it seems to perform well based on reviews and may be a viable option to consider for a larger tank that is battling a large quantity of Majano or Aiptasia.

All photos by ReefCorner © All Rights Reserved