The results of the survey are contained in the article below:
Contents
1. Aims of survey
A number of survey respondents sent in some lovely photos of their anemones. The only pity is I could not include them all in this publication. This beautiful specimen is in the tank of
Eugene Schwartz. In another tank Eugene has a Heteractis crispa that he described as a rescue mission. Bought bleached, Eugene restored it to its former glory and color by careful feeding and correct lighting and environment.
1. Aims of Survey
The primary aim of the survey was to gather data on anemones that have lived a comparatively long time in captivity, and attempt to identify any common factors in their care, with enough consistency and quantity to give a statistically valid basis to believe that these factors have been important to their long rate of survival in captivity. In this way it was hoped to be able to provide accurate recommendations that would enhance the health and longevity of captive anemones.
2. Methodology
A questionnaire was distributed via the internet for anybody having an anemone that had lived more than two years in captivity. The survey was confined to clownfish hosting species.
I would like to thank all who took the time to complete this questionnaire and return it to me.
Data was eventually collected on 137 anemones, and time spent in an aquarium ranged from two to fifteen years. Eighteen anemones had been in an aquarium for ten or more years, and the median time was six years.
A spreadsheet was set up for each species, and data entered in such a way that any that data clusters could be easily seen, and widely dispersed data could be easily seen. The spreadsheets could also be cross referenced, so that data patterns across several or all species could be identified. The data was also weighted so that data from the shorter lived anemone had less importance than data from longer lived ones. In the end, the weighting had little effect, the results would have been very similar with no weighting.
The responses have provided sufficient data to reach statistically valid conclusions in some areas, but insufficient data in other areas. Also, the complexity of relationships between various environmental factors in an aquarium made it difficult to get an accurate perspective on some factors individually. For example, to get an accurate picture of the effects of pH, it would be necessary to look at a range of pH readings, where all other variables are equal. There was just not enough data to do this. However, where data was insufficient to be valid statistically, there were sometimes clear trends visible, which when combined with comments provided by the respondents, produced reasonable grounds to reach certain conclusions. I have therefore decided to depart from my original plan of producing a report based only on statistics, to one which is a combination of hard data plus comments and anecdotal evidence provided by the respondents. While this approach may not be deemed quite as accurate, it should be born in mind that this information represents the combined knowledge and practises of all the respondents. It has been estimated that only around 5% of captive anemones make it past two years, so the respondents to this survey can be regarded as people who are doing most things right. This can also be born out by the calibre of the respondents, which included some well known authors, and also people involved commercially in the aquarium trade.
3. Results and Conclusions
A lot of the information was true to all anemones, although some results were localised to particular species, so there is also another section to deal with that: Species Specific Information.
It was hoped that the survey would yield some hard and fast rules, or a major breakthrough, to ensure anemone health, however this just did not happen. No major breakthroughs were made, in fact it was more a case of the conventional wisdom in most cases being confirmed.
One thing that really did come through though was that virtually all survey respondents ran very stable, well equipped tanks, and had a very intimate understanding of the health and requirements of the tank inhabitants. Some of them reported that they rarely if ever tested the tank water, relying instead on observation of the livestock to tell them if anything was wrong, in which case they would test. This mindset only comes about after long experience running a system so stable that the owner becomes confident to take this approach. There was not one reply from someone who had a tank that was poorly managed or unstable. Therefore a basic prerequisite must be to have a solid, stable system.
The other thing that came through was the prevalence of the species Entacmaea quadricolor, in fact around 50% of replies were about this species. More will be said about this anemone in the species specific section, however it was obvious this is the species that will perform best in an aquarium. Other species were notably under represented, such as Heteractis magnifica, despite being sold in reasonable numbers, it does appear that this species, while a beautiful anemone, is likely to do badly and die in an aquarium.
Water Chemistry:-
Ammonia and Nitrite. Only zero values were reported for these.
Nitrate. Almost half of respondents reported values greater than zero for nitrate, but the majority of these were lower than 5 ppm. Most of the rest were lower than 10 ppm, however there were a few values up to 20 ppm, and surprisingly, one was reported up to 40 ppm. Based at face value purely on the numbers, it would appear that nitrate below 5 ppm has no detrimental effect, 5-10 ppm is getting borderline, and longevity is much less represented in systems with greater than 10 ppm.
pH. Almost all respondents reported pH values around 8.0 to 8.4, the most common being 8.0 to 8.2. Some individual systems did fluctuate by up to 0.3 daily. There were some long lived anemones in systems that occasionally dipped as low as 7.8. Most pH values were very stable though, indicating that stable pH is an advantage, but not critical.
Alkalinity. Few extreme values reported, mostly within the 2.8 to 4.0 mEq/L range.
Calcium. Again, few extreme values reported. The majority very close to 400, and nearly all between 380 to 450. The highest was 470, and the lowest 320.
Iodine and trace chemicals. Not enough data was collected to reach any valid conclusions with these, however all the values that were reported were within ranges considered normal, there were no extreme values.
Salinity. Was mostly reported in SG. Nearly all were either 1.024 or 1.025, and a smaller number at 1.026. A few, but not many, other numbers were reported, however the near absence of any other numbers may indicate this to be of greater importance than may be generally realised.
Temperature. The majority were 80 or 81, and some at 82. Some other mainly lower numbers were reported. Many systems had some fluctuation. Some systems very stable, however it would appear that a few degrees gradual fluctuation does not do much harm.
Lighting:-
Basically, the conventional wisdom was confirmed here, that strong lighting is best, although there were exceptions. Over 90% of anemones were under metal halide (MH) lights, or MH in combination with something else. The others were under Very High Output (VHO) fluorescents, power compacts (PC), or various combinations. Nearly all systems included actinics. Among other examples of success without MH, was an E. quadricolor which had been kept for 5 years under PC lights, was in top health, and had produced a good number of clones which had been sold.
Some respondents with very bright MH reported that the anemone actively tried to get in the most possible light, while a few owners said they did not consider lighting hugely important.
The lighting was very difficult to properly analyse, not knowing the exact position of the lights. Plus, the position of the anemone has a huge effect. Just simply looking at the particular light set up does not tell the full story. However it can be said that the general leaning was towards very strong lighting. The anemones under less than MH were nearly all in very small tanks. Just a word to those who are wondering why their anemone is moving around, current and substrate also play a part here. A number of respondents said their anemone stopped wandering once it found the correct combination of light, current and substrate.
Feeding:-
A very few people said the anemone was not fed at all other than a bit of stray fish food, but nearly all anemones were target fed, with various types of shrimp food featuring highly on the menu. Some anemones were being fed quite large amounts, likely more than the rest of the tank inhabitants combined. As a supplement additive, Selcon was mentioned quite a few times. Some people placed great importance on the feeding, and carefully combined various food types plus supplements to achieve a very rounded diet. Overall, it did appear that by whatever means, most anemones were getting a varied diet likely to contain a wide range of the various nutritional requirements that would be necessary.
Water Changes:- Nothing special to mention here, most respondents were just performing the normal type water changes one would expect to see of any well run aquarium.
4. Species Specific Information
note:- only a few species mentioned here as some species do not have any special information not covered above.
Entacmaea quadricolor. This species really did emerge as the star performer. Not only was it much more likely to live a long life in an aquarium than any other species, but it was also reported as reproducing readily.
E. quadricolor appears adaptable to a range of conditions, doing well under very high lighting, but able to live under tube only lighting also in some set-ups. It can also live with low, medium or high current, but would appear to favour medium or high. Reproduction was often in response to a stress event, often reported in newly purchased specimens recovering from the rigours of being shipped. It may be that the anemone having survived what to it was a cataclysmic event, reproduces, to ensure survival of the species.
A drawback with this species is that it was often reported as a wanderer, prone to doing damage to both its surroundings and itself as it moves around the aquarium. However, it was also reported as staying in the same place for several years once it found a really good spot. One example of this was a respondent who said his E. quadricolor liked a spot where it was attached to the underside of an overhanging rock, but reaching out into the tank in a position of high light and strong current. Knowing his anemone's preference for this type of location, when it had to be moved to a new tank, the owner deliberately created a similar type location in the new tank, and the anemone moved around the tank until it found it, and then stayed put.
This anemone was referred to by a number of owners as hardy, and it appears that it is, given a liveable environment. Although it is hardy by anemone standards, it must be remembered that it still requires a good high quality environment.
If you combine all the above with the fact that this is an attractive anemone that has also been reported as hosting a wide range of clownfish species, it really should be the anemone of choice for most aquarists. Looked after properly it will reward its owner by maintaining good health and possibly producing clones, and will also assist conservation by reducing the removal of other species from reefs, which will likely die after a year or two in an aquarium.
Heteractis magnifica. Very strong lighting, very strong current. Other than that, not enough data was gathered to say much because of the poor survival rate of this species in aquaria. A beautiful anemone, but not for beginners, and maybe one that really should just be left in the wild.
Heteractis malu. A sand burrowing anemone regarded as less attractive than most species. It was reported as living in sand as shallow as 1 1/2 inches, however to really make this anemone happy, a 6 inch deep layer of sand is required. The reason I rated this species a mention is it has one big attribute. That is, that given the right place, it will stay put without moving for years. As it is also relatively non aggressive chemically, this makes it a better suited candidate for a reef tank. If this anemone is in shallow sand it will move around looking for something deeper to burrow into, and may wilt and die. However, given six inch deep sand it will burrow in and then stay put (assuming other conditions are OK). It was reported as living under high, medium, and low (tube) lighting, although the tube lighting was a very small tank. Current was more low or medium for this species. It readily hosts Amphiprion clarkii and A. occelaris clownfish, but was also reported hosting some others.
Sand Burrowing Anemones (several species). The trick appears to be to give them a good deep bed of sand to burrow into, up to 6 inches deep. Not so important for species that will either burrow or live in rocks or coral, but specialist burrowers were described several times as only really settling down once they had some good deep sand to get into. Having said that, there were examples of them living in sand as shallow as 1 ˝ inches, in some of these cases it was mentioned that they had also burrowed under a rock, which may have helped them feel burrowed in. Attack from below by bristleworms was mentioned as a potential problem for these anemones.
5. Final Comments.
What has come through this survey is that there is no one “magic bullet” to anemone keeping, but rather attention is needed to getting everything right. Following the parameters outlined above will provide a long term environment for the more easy care species such as E. quadricolor. All the respondents had tanks that were stable and well equipped and managed. The levels of things such as calcium tended to be conservative and close to natural seawater. There were few extreme levels. The fact that there was not a single reply from someone with an unstable or poorly run tank really shows that anemones just are not going to make it long term unless conditions are good. That said, some of the older anemones had been moved several times to a number of different tanks and different conditions, but had adapted as the conditions were still liveable and the anemone health good.
A conclusion that could be made is that conservation of wild stocks could be enhanced by making Entacmaea quadricolor the anemone of first choice, because it would appear that while it can be done by some experienced aquarists, generally only a small minority of anemones from each of the other species make it for any reasonable period of time in an aquarium. This has resulted in the complete removal of anemones from some reefs, which of course also leaves the clownfish without a home - a great pity when they are only going to decorate someone’s tank for a year or two and then die. Entacmaea quadricolor, on the other hand could easily become a completely renewable resource, as the responses to this survey have given numerous instances of them reproducing in captivity.
Comment should also be made on a leading reported cause of anemone deaths, which was through injuries resulting from contact with a powerhead. This was repeated over in many emails, often with anemone that had otherwise survived well for many years. It would therefore be good practise to install some form of protection over water intakes, to remove this threat.
These are the results of the Anemone survey conducted September 2003, by Alastair Little.
Contact:anemonesurvey@yahoo.com.au (This address will remain active through 2003.)
2. Methodology
3. Results and conclusions
4. Species specific information
5. Final comments
