Berghia Nudibranch - The Natural Choice For Aiptasia Control

To best understand the Berghia nudibranch, we must first have an understanding of its prey, the Aiptasia sp. Anemone. (Complete information on Aiptasia is available in our Aiptasia Information section)

True to their name, Aiptasia sp. Anemones (which means ‘beautiful’) are elegant creatures, but they are also invasive and aggressive competitors in the reef aquarium. Left unchecked, they will often totally over-run a marine aquarium stinging any near by corals requiring apitasia anemone control.

When Aiptasia are disturbed (either by a passing fish or invertebrate) they eject dangerous white stinging threads that contain venomous cells called nematocyst. These nematocysts are capable of delivering a potent sting that can cause tissue regression in sessile corals, immobilize prey, and even kill unlucky crabs, snails or fish.

The Aiptasia anemone is capable of spreading rapidly in a reef aquarium due to its ability to reproduce both sexually and asexually. The missed fish food particles then caught by the Aiptasia anemone also helps to speed their spread in the home aquarium.

Asexual Reproduction

Aiptasia reproduce asexually by pedal laceration. Small masses of cells are pinched or torn off the margins of the pedal disk at the base of its central column. These grow slowly into buds and within a week or two after completely separating from the foot the bud develops a mouth and small tentacles and begins to feed on its own. Some of these clones will release and be distributed in the water column to colonize other locations in the aquarium. Sometimes near your loved corals. Additionally, Aiptasia demonstrates a preferential tolerance to its own clones and will not sting them. This allows large groupings of Aiptasiaclones to form as a result of asexual reproduction.

Unlike some cnidarians, Aiptasia are extremely successful in generating or regenerating an entire animal from just small pieces of a larger aiptasia. It is because of this that physical removal is so difficult to perform successfully. Any piece of Aiptasia anemone not removed can restart the infestation.

Aiptasia have been know to increase asexual reproduction during times of extreme stress. Some of the causes of stress to aiptasia in a reef aquarium are low oxygen, decreased circulation during power failures, low lighting situations, attack by predators or when the saltwater aquarist attempts physical or chemical methods of removal.

Sexual Reproduction

While there is little scientific documentation on the sexual reproduction within Aiptasia, general observations indicate the sexual reproduction may occur in two forms.

In the case of the well-studied Aiptasia pallida and Aiptasia pulchella, individuals are dioecious, meaning that individual Aiptasia are of separate sexes. During spawning, Aiptasia anemones release their gametes into the water where fertilization occurs. The resulting zygote becomes a free swimming planula larva which eventually settles onto a suitable substrate and undergoes metamorphosis to become a Aiptasia anemone small polyp. Newly produced aiptasia larvae are aposymbiotic meaning they do not contain symbionts. The larvae or newly settled polyps acquire symbiotic algae from their aquarium environment.

In certain species of Aiptasia fertilization may be internal, in the coelenteron. Male gametes are released from male Aiptasia into the water column. These gametes are non-buoyant and settle to fertilize the female gametes within other Aiptasia. These fertilized eggs develop internally within the Aiptasia into Planula Larva. As the anemone larvae develop, they receive nourishment from the ‘mother’ Aiptasia. When conditions are optimal (light and nutrients are high), or during physical attack (as when an aquarist is attempting to remove them), these larva are released into the water column to start growing and colonizing other parts of the home aquarium.

Considered by most reef keepers as a pest (and often referred to as the ‘weed’ anemone) this hitchhiker often enters our marine aquarium on a piece of live rock or attached to coral fragments, often too small to see – at first. Then quickly, the Aiptasia begins multiplying, reproducing both sexually and asexually. What began as one or two hitchhikers now becomes a full blown aquarium infestation.

Left unchecked by its natural predators, the Aiptasia anemone will quickly overgrow the reef tank, stinging (often to death) many live corals that it encounters, while posing some risk to fish and invertebrates alike.

So what can be done?

Why Choose Berghia nudibranchs?

So you have discovered that you have one or more Aiptasia living in your reef tank (or many more if you’re like most saltwater aquarium enthusiasts encountering Aiptasia for the first time), what are the options?

‘Quick-Fix’ Chemical Solutions

There are many commercial solutions marketed for the control and elimination of Aiptasia anemones in the marine aquarium. These chemical ‘quick-fixes’ all contain harmful ingredients that will alter your saltwater water chemistry – affecting the pH, alkalinity and various other water parameters to some degree. Some are also deadly toxins, killing not only the Aiptasia they are applied to, but all life they come in contact with. While touted as reef safe, most contain ingredients are harmful to reef aquarium organisms good and bad.

Worse of all, most (if not all) fail to eliminate your problem, and often only make the condition worse by triggering the Aiptasia’s aggressive reproductive system to create even more of the aiptasia pests in your loved reef aquarium.

Natural Predators?

The internet is filled with stories of success and failure associated with several reported Aiptasia predators, with everything from invertebrates like Peppermint shrimp, to saltwater fish like the Copperband butterfly and filefish being proclaimed as the solution for an Aiptasia anemone infestation.

However, the recommended saltwater fish are commonly not reef safe and will browse on various types of soft and stony corals, zoanthids, sea mats, and polyps.

Many of the animals listed naturally feed on various types of both sessile and motile invertebrates, such as desirable sea anemones, feather dusters and other tube worms, clams, sea urchins, and crustaceans.

So basically it’s trading one pest for another.

What’s most important to note about these ‘natural predators’ is that none of them feed on Aiptasia as a primary food source. They all ‘may’ browse on Aiptasia if other sources of nutrition are unavailable, but given an ample alternative, few will resort to consuming the Aiptasia anemone as their main food source.

The True Natural Solution

The Berghia Nudibranch

Fortunately, Nature has developed a solution, the Berghia nudibranch (formerly known as Berghia verrucicornis and recently reclassified as a new species Aeolidiella stephanieae). Through millions of years of evolution, the Berghia nudibranch has evolved to feed on the Aiptasiaanemone, and only on the Aiptasia anemone. In fact, without Aiptasiapresent, the nudibranch will starve to death. So unlike all the other ‘natural’ solutions, the Berghia is the only creature guaranteed not to nibble on your prized corals or to harm any other life in your tank.

Because of their small size, they add very little bioload to your reef and will not affect they water quality of your tank.

They are harmless to fish, won’t compete for space or food and being nocturnal, generally go completely unnoticed in a reef tank (except for the steady removal of the Aiptasia).

Size matters

Aiptasia are well adapted to survive in the reef aquarium. Since the Aiptasia anemones do not rely on light as its only source of nutrition, they can be found happily living under live rock, in small crevices and under live coral. All these places can difficult to reach for the reef aquarist armed with a syringe full of anti-Aiptasiachemical, or for Aiptasia browsers like the Copperband butterfly.

But this is where the small size of the Berghia pays off (adults reaching 1 to 1½ inches in length). They are able to crawl into the smallest crevice, under live rock, or underneath large corals to reach the Aiptasia. This is all done without harming the corals or upsetting the aquarium rock work. Unlike any other Aiptasia‘cures,’ Berghia nudibranchs will consume every last part of the aiptasia anemone, leaving nothing remaining to reproduce and infest the marine aquarium.

Even though the Berghia nudibranchs are small, they will still consume Aiptasia many times larger than they are, eating even very large Aiptasia that other ‘predators’ tend to shy away from.

Strength in Numbers

Berghia occasionally reproduce in the saltwater display aquarium. Being hermaphroditic, each mature Berghia nudibranch may mate and lay eggs every day as long as water conditions are good and an amply supply of Aiptasia are available. This allows the Berghia nudibranch to increase their colony size relatively in order to deal with large Aiptasia anemone infestations.

SIZE 1/4-3/8 inch