Angelfish and anemones

In this post, we will learn a little about the interaction between Angelfish and anemones in an aquarium, as well as in their natural habitat.

Angelfish and anemones

Angelfish are often associated with coral reefs, in these environments, we also find animals such as anemones. The two are animals with very different temperaments. Although their life cycles are very different, both need very similar conditions in the aquarium. Thus, facilitating the coexistence of these two species.

Anemones and their characteristics

Sea anemones belong to the order Actiniaria, there are four suborders and forty-six different families. The anemone is a predatory animal related to corals and jellyfish.

The basic anatomy of an anemone includes a polyp attached to the underside of a basal disc, a column-shaped body extending from the disc and terminating in an oral disc. You are probably familiar with sea anemones concerning their symbiotic link with clownfish.

Most anemones grow between 1 and 3 inches in diameter, but some are as small as 0.5 inches. These creatures can display anywhere from a few dozen to a few hundred tentacles. Anemones use an oral disc to imprison their prey and can adhere to the substrate.

Main species of anemones for marine aquarium

There are many different species of anemone out there. If you are thinking about adding one or two anemones to your marine aquarium, here are some anemone types.

Bubble anemone (Entacmaea quadricolor)

The bubble anemone or bulb anemone is one of the most commonly found anemones in marine aquariums. These anemones usually have brown columns with orange, green, brown, or glowing tentacles. 

Adhesive Anemone (Cryptodendrum adhesive)

This type of anemone is sometimes sold as a “pizza anemone” because it has rounded edges that resemble a pizza dough. Adhesive anemone is very unique in appearance, but has a powerful sting – it may not do much harm to humans, but it can be dangerous to certain aquarium inhabitants.

Beaded anemone (Heteractis aurora)

The beaded anemone is named for the swellings along the length of its tentacles which can be brown, green or purple. This species tends to burrow in sand or gravel rather than anchoring itself to a hard substrate and is a host for several different types of fish. Keeping this species of anemone in a marine aquarium is quite easy, as long as a thick bed of sand and adequate lighting are provided.

Corkscrew Anemone (Macrodactyla doreensis)

The corkscrew anemone has an opaque orange or red column with several rows of small bumps rising along its length. These species prefer soft substrates, to bury the base in sand or mud. When provided with suitable habitat, the corkscrew anemone is a very hardy species and a great choice of anemone for the marine aquarium.

Requirements to have anemones in the marine aquarium

While aquarium conditions vary from one anemone species to another, all species have several requirements in common. The first is that the water quality in the tank must be very high. The water must be clean and free of accumulated debris.

Oxygenation

Sea anemones require high levels of oxygen dissolved in the water and also pH levels ranging between 8.1 and 8.3.

Anemones in marine aquariums do best when there is a good level of oxygen in the water. This is not very different from other animals in general and can be easily achieved with a good movement of water on the aquarium surface and using a protein skimmer.

Marine aquarium temperature

The water temperature for anemones should vary between 75 and 78 degrees Fahrenheit. Salinity should remain stable between 1024 and 1026. Phosphate, ammonia and nitrite levels should be as close to 0 as possible and nitrate should not be more than 2ppm.

Water flux

Another important aspect of keeping an anemone in a marine aquarium is achieving the optimal level of water movement and flow. This will sometimes make them move until they find a comfortable spot on the tank.

The water flux assists the anemones in acquiring oxygen directly from the water and this can also help them in collecting food particles from the water column. In the case of slow-moving water or no movement at all, the anemones will not be able to get the oxygen required or their food.

Most species do well in tanks with moderate flow, but some species may be more required of higher flows. Anemones are not photosynthetic organisms but obtain essential nutrients from the photosynthetic algae that grow in their tissues. Thus, it is important to keep good lighting conditions For that reason,  it is recommended to equip your tank with a full-spectrum light – preferably one that is designed especially for marine and reef aquariums.

Lighting

Anemones need very good lighting to survive, similar levels to corals. They will receive many of the necessary nutrients through photosynthetic processes from algae present around or in their tissues.

The high quality LED will also provide all the lighting needed for an anemone in the marine aquarium. Typically, if your lighting is a little less than ideal for your anemone, you can make up for it with a few regular meals.

Reproduction anemones in a marine aquarium

Many species have separate sexes, which facilitate the reproduction of anemones in the marine aquarium. Male and female gametes are released from the mouth in a coordinated manner. The eggs develop then into swimming larvae, which will search until find a appropriate substrate to develop into a polyp.

Asexual methods are also employed. Budding, or the formation of small replicas of the parent anemone, can be seen in some species. Alternatively, binary fission, during which the anemone splits in two, may be used by some species.

Anemone compatibility

Many anemones are added into ready reef aquariums with corals and other invertebrates. However, this may not be a good idea, as some anemones can employ “chemical warfare” against other cnidarians and conspecifics.

Also, keep in mind that many species of fish would naturally nip at anemone tentacles, so never house them with butterflyfish, angelfish, pigfish or large pufferfish. Cautious choice of tank mates is fundamental and mixing conspecifics necessitates a lot of space.

Ideally, always research the species of animal you want to add or that you already have before adding an anemone in your marine aquarium.

Many fish species, on the other hand, benefit from anemones in the marine aquarium. Clownfish, for example, can even use them as hiding places in a relationship that turns out to be beneficial for both of them.

Anemone feeding and care

Another mistake amateur hobbyists sometimes make is not adequately feeding their anemones. Some aquarists believe that the anemones in marine tanks can get plenty of food from the water column and algae that grow in their tissues. However, it is important to feed the anemones a few times a month to ensure they do not starve. To speed up the growth of your anemones, feed them once a week or more often. The recommended items for these animals are protein-rich food sources such as scallops, shrimp, and mussels.

Placing the anemone in the marine aquarium

Placing the anemone in the tank can also be challenging for aquarists. Before purchasing an anemone, research the particular species to find out which location they prefer in an aquarium. Some species prefer to attach themselves to a crevice in a rock while others burrow directly into the substrate.

Are anemones compatible with angelfish?

Although angelfish temperament is a recurrent subject in many groups of aquarists, there are few reports of problems when pairing an angelfish and an anemone in the aquarium. In nature, the angelfish is found most often in coral reefs. Though there is generally a friendly relationship between these animals, there is no evidence of a symbiotic relationship such as clownfish.

So, following all the necessary steps for a good environment for these two species, it is possible, yes, both harmoniously coexist in an aquarium. However, keep in mind that some angelfish species can start nipping at anemone tentacles. Thus, this combination should be observed.

Conclusion 

In this post, we learnt a little about the interaction between angelfish and anemones in an aquarium, as well as in their natural habitat.

If you have any thoughts or doubts, feel free to drop us in a comment below!

Frequently Asked Questions (FAQs): Angelfish and anemones

How to raise anemones?

Anemones need light to help prepare foods that help with energy and growth. For this reason, at least moderate lighting requirements should be a priority. Additionally, it is necessary to set ideal temperatures and pH levels.

Why does the anemone close?

This behaviour is normal, it usually does it after a meal to expel the detritus, as it has an extremely simple digestive system with only one aperture, it compresses itself all over to get out what is left of the digestion.

How to feed an anemone?

The frequency of feeding the anemone is fundamental. You cannot overdo it, as anemones are very slow in the digestion process.

What to give for the anemone to eat?

There are several food options, such as shrimp, squid, sardine, and other animals pieces. 

Is Coral the same thing as anemone?

No, they are different organisms. However corals and anemones are members of an animal phylum called Cnidarians, coral is made up of many tiny individual structures grouped. A single coral is a composite of structures called polyps and a limestone skeleton.

References 

Barrington, K. 2020. Guide For Keeping Anemones in a Reef Tank. https://www.ratemyfishtank.com/blog/guide-for-keeping-anemones-in-a-reef-tank

Fatherree, J. W. Aquarium Fish: Animals That Associate With Anemones (other than Clownfishes).

Gómez-Laplaza, L. M., & Gerlai, R. (2013). Quantification abilities in angelfish (Pterophyllum scalare): the influence of continuous variables. Animal Cognition, 16(3), 373-383.

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