Coral Reef Magazine Volume 2

by Coral_Reef_Magazine Thu 21 May 2015, 18:30

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Coral Reef Magazine Volume 2
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Page 1
HERE’S HOW TO CATCH YOUR FISH IN THE AQUARIUM – PART 2

Page 2
HOW TO TRAIN PREDATORS TO EAT FROZEN FOOD

Page 3
ALGAE INFILTRATION IN SILICONE

Page 4
Amphiprion leucokranos by ORA

Page 5
PTERAPOGON KAUDERNI, POSSIBLE INCLUSION IN THE ENDANGERED SPECIES ACT?

Page 6
THE WILD GOLDEN CLOWNFISH

Page 7
CLOWNFISH HAPPY TO COMMUNICATE

Page 8
THE TWINSPOT CORAL BLENNY (ECSENIUS BIMACULATUS)

Page 9
ACTIVATED CARBON FOR MARINE AQUARIUMS – Part 1

Page 10
ACTIVATED CARBON FOR MARINE AQUARIUMS – Part 2

by Coral_Reef_Magazine Thu 21 May 2015, 18:32

HERE’S HOW TO CATCH YOUR FISH IN THE AQUARIUM – PART 2

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Points of view

Every aquariofile has had to catch some fish in their aquarium at some point, to transport them elsewhere. In the past it happened often to give treatment to ill specimens, but in modern aquariums the diseases of coral fish are relatively rare, and so catching them is necessary mainly when the cohabitation of different species or sexes becomes difficult and creates problems. Otherwise it is necessary when a fish grows to be too big for the aquarium, although this should not happen if you take into account the size that the animal will be as an adult from the beginning. There are some great fish “traps” that have guillotine style trap doors, which can be activated remotely. Some even have a tube through which to send the food inside, as bait. At first it seems that these would be very good premises for the capture, and at least in theory catching coral fish in an aquarium should not be a problem. However, there is a big difference between theory and practice. The bravest fish quickly enter the trap. These are often not the ones we want to capture, and it seems as if they know it too! If you try to capture a specific individual of the community, then you will soon face the problem that the fish in question will understand that he is the one that you want.

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If you stare at the fish you want to catch, it is unlikely that it will get into the trap. Photo: D. Knop

All the other fish go into the trap, but not the one you want to catch. Why does this happen? I remember well the attempted capture in one of the aquariums of behavioural researcher Prof. Doctor Ellen Thaler. For some studies these aquariums are occasionally populated with certain fish, so that some of the original occupants have to be removed beforehand. That is exactly what she intended to do, and she had to capture a considerable part of the occupants. Certain fish were not initially on the list, so they often entered the trap but were ignored. Then it was decided to include them in the list of fish to remove. Oddly, from that moment they did not enter the trap any more! What could this depend on? Were they able to read the list? Almost every fish that we intended to catch seemed to avoid the trap, like the devil with holy water! How could the fish understand our intentions? In the end, the capture of two Zebrasoma flavescens turned out to be particularly difficult. We were about to give up when suddenly we made the connection. We were revealing to the fish that we were targeting it! Involuntarily and subconsciously we were telling it “you are the one we want,” simply by observing it incessantly, in the hope that sooner or later it would get into the trap. A coral fish understands well whether it is being observed or not, since this knowledge is of vital importance in nature. It is literally a question of “point of view,” if the fish feels observed by one or even two pairs of eyes, it will avoid the unusual cave full of plastic and the unknown, despite the tempting food. This is, in fact, the omnipresent dilemma between hunger and fear. If the fish feels observed then caution will prevail, but if it feels that the objective is someone else than it will be more likely to go into the trap. Therefore, you should not stare at the fish you want to catch too much, but you should direct your attention to others, or, even better, to none of them, positioning yourself two or three metres away. The guillotine style trap door can be activated with a long nylon cable. For example, you can attach a container with a plastic lid to the extremity of the cable (securing the cable between the container and the lid), and place a weight in the container so that it will stay still on the table and keep the trap door open. To close the trap door, you will just have to move the container in the direction of the aquarium. The advantage is that it is not necessary to hold the cable in a certain position with your hand, which is quite tiring.

What to do when the dominant fish take control of the trap, while the smaller and submissive ones, that you want to catch, wait at a distance in either respect or fear? In this case, it does not help to keep adding food in the trap to satiate the bigger fish, as many small fragments of food will make their way outside the trap while they eat, giving the other “observers” the chance to fill up too. This is a big problem, especially when you want to remove a submissive fish from the tank, since it tends to be overpowered by others. In this case the only thing that helps is to pre-emptively capture the bigger and dominant specimens, temporarily keeping them in a separate tank or in another appropriate container (for example a plastic container prepared for this purpose with the water taken out for a partial change). If you place the trap in the aquarium again, and without making any sudden movements, the remaining fish will soon show a renewed interest in the food. In the next issue’s editorial there will be all the tricks and advice for the capture of fish in the aquarium.

Daniel Knop

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Page 1

by Coral_Reef_Magazine Thu 21 May 2015, 18:35

HOW TO TRAIN PREDATORS TO EAT FROZEN FOOD

[You must be registered and logged in to see this image.]Some fish find it hard to get used to eating food that is not alive, because their predatory instinct gets activated by the movement of the animal that they have to catch. This happens mostly in the case of ambush predators.

For these fish, you can use the following method to train them to accept frozen food:

Take a nylon thread and roughen up one of the extremities.
This part of the thread can now be inserted under the shell of a shrimp.
The rough extremity of the nylon thread holds up the shrimp hanging from it, but it also makes it easy to remove for the fish.

With this method you can make the shrimp move in front of the fish, stimulating its interest for the prey. In this way, fish get used to being fed non-living food more easily. Before they are fed to the fish, the shrimps are also easy to enrich with vitamins or medicinal substances. The best way is to insert the solution under the shell (as shown in the picture).

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Page 2

by Coral_Reef_Magazine Thu 21 May 2015, 18:39

ALGAE INFILTRATION IN SILICONE

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Several types of algae, here Ventricaria, can infiltrate even black silicon. Photo: D. Knop

Black silicone has been for a long time considered highly effective, because it prevents the aquarium’s lighting from filtering out. The common opinion was that because of that, the growth of algae between silicone and glass would be inhibited. But it has been proved that for some types of algae what little light gets reflected by the glass is enough for it to grow without problems. Therefore, at least once per year, check the seals of the aquarium even in the most difficult to reach parts, to identify possible algal infiltration, which if present should be eliminated immediately. Small cavities in the silicon seal can be filled with special epoxy resins, to prevent algae from infiltrating the seal again. In case the infiltration of the algae has already compromised most of the seals, you can remedy by attaching an additional strip of glass on the outside. In this way, you avoid emptying the aquarium.

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In case of algae infiltration, adding a strip of glass can avoid water leakage.

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Page 3

by Coral_Reef_Magazine Thu 21 May 2015, 18:43

Amphiprion leucokranos by ORA

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Today we want to recommend a beautiful video released by a world famous company that specializes in marine fish and invertebrate aquaculture, ORA Ocean Reefs e Aquariums.

For those who have never heard of ORA, their aim is to provide a complete range of “aquacultured” products that can safeguard the future of this hobby while preserving the natural environment of the coral reef.

The video, which is sped up by twenty times, follows the third deposition of a pair of Amphiprion leucokranos that until now has had a troubled history (during the delivery the package was lost, but despite that the couple held out and made it in perfect shape to headquarters). We recommend you read the ORA blog to read the whole chronicle in detail. We also recommend watching the video in high definition at 1080p.

Considering the excellent worldwide reputation of these aquaculturers, we are pretty sure that in a not too distant future we will see the ORA Leucokranos on the market.

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Page 4

by Coral_Reef_Magazine Thu 21 May 2015, 18:47

PTERAPOGON KAUDERNI, POSSIBLE INCLUSION IN THE ENDANGERED SPECIES ACT?

[You must be registered and logged in to see this image.]The Banggai Cardinalfish, Pterapogon Kauderni, is the last target of a group of environmentalists that are trying to add the fish and other animals to the Endangered Species Act. For those who don’t know,ESA is a law created in 1973 for the conservation of species at riskor that are threatened. The petition was presented by WildEarth Guardians, a no-profit environmentalist group that apparently has a petition for more than 700 species ready.

They are trying to reach a total of 81 species in the SEC, which includes:

23 corals
22 sharks
15 vertebrate fish
10 rays
5 marine mammals
3 Myxinidae
3 sea snakes

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After reading the 538 pages petition, the National Marine Fisheries Service (NMFS) has found that there wasn’t enough proof to go ahead with the process, but a state revision could move it either to the candidate list or reject it completely.
The implications that this would have if it was enforced would be that, first of all, captured Pterapogon Kauderni would not be available on the market anymore. While from the point of view of conservation, the ESA quotation would have an impact on aquaculture, and there would be no chance of a Banggai Cardinalfish being commercialized even if they were bred in captivity.

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Page 5

by Coral_Reef_Magazine Thu 21 May 2015, 18:52

THE WILD GOLDEN CLOWNFISH

[You must be registered and logged in to see this image.]What do you obtain if you cross a Tangerine Orange clownfish with a Naked Ocellaris?

The result would probably be a huge mess!

But in a perfect world where our dreams come true… a golden orange clownfish might come to life.

Well, Dr. Chung Ala Hung, who is widely recognized and has proven experience, has recently added to his aquarium an Ocellaris caught in the wild that has unique and perfect features. It is the complete and total absence of black pigment that makes this specimen unique, because wild Ocellaris and Percula clownfish with no black stripes are not news.

In the video that Dr. Chung has recently released, we can see the newly acclimatized golden orange clownfish (Ocellaris Golden) leisurely swimming around.

The next step will be to study the specimen to try to reproduce it like it is usually done with other more common Ocellaris, a reality that is still different for albinos, which today still present some difficulties and whose reproduction has been successfully induced by only three institutes.

While we wait for the genetic test of the fish, we cannot but be amazed once again at the surprises created by the ocean.

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Page 6

by Coral_Reef_Magazine Thu 21 May 2015, 18:55

CLOWNFISH HAPPY TO COMMUNICATE

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Fish can definitely talk

They rub their bones together, making sounds that are audible with the aid of their swim bladder, or otherwise they can even communicate by emitting air from their anus.Fish can definitely talk.

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CORALLI has reported about this strange means of communication in herrings. People think thatfish cannot talk especially because the majority of them produces infrasounds, which the human ear is incapable of hearing as their frequencies are too low. The first recording of sounds made by pomacentrids, which remind of a creaking door, was made back in 1930, but the mechanism that produces them has remained unknown for a long time.

Now, some researchers from Belgium and the U.S. have discovered, and published in the specialized magazine “Science,” how sound production works in the clown fish Amphiprion clarkii. Many strident or creaking sounds are produced by the movement of the jaw and the rubbing of the teeth. Clown fish make these sounds during the search for a partner or while defending their territory.

It was a discovery by Eric Parmentier from the Université de Liège (Belgium) and his collaborators, obtained through a combination of recordings of sounds made by Clark’s Anemonefish (Amphiprion clarkii), video footage and x-rays of the animals.

The result:

The sounds are created when the base of the tongue clamps vertically at the same time as the jaw; the teeth clash against each other and send energy to the jaw, which transfers the sounds outside. The closure of the lower jaw is made possible by a structure that was unknown until now and that resembles a bridge.

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Page 7

by Coral_Reef_Magazine Thu 21 May 2015, 18:57

THE TWINSPOT CORAL BLENNY (ECSENIUS BIMACULATUS)

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Distribution: Western Pacific; Philippines and Malaysia.

Description: The blennoid Escenius Bimaculatus, with a maximum length of 5 cm, is one of the smallest members of the family. It can be easily distinguished from other very similar species that are common in the Indo-Pacific thanks to the two black spots on the abdominal area.

Lifestyle: In nature the twinspot coral blenny lives in the shallow waters of coral reefs, where it grazes on the tenuous algal covering of rocks, always on the lookout for predators, and in case of danger it disappears as quickly as lightning between rock crevices or small recesses.

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Care in aquariums: Because of its small size and calm behavior, Ecsenius bimaculatus can be kept even in nano reef aquariums from 30 liters, as long as there are enough hiding places. Keeping them as a pair is possible in slightly bigger aquariums, if it is possible to find two seemingly tolerant animals. In any case, you should never introduce two animals together arbitrarily. These blennoids are remarkably aggressive towards disliked animals of the same species.
Feeding: When kept in an aquarium it usually accepts frozen food and even dry food, but on the long term the well being of these blennoids should always be based on vegetable food. If there is no algae growing on the rocks that can be grazed as in the natural environment, Nori seaweed can be an acceptable substitute.

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Page 8

by Coral_Reef_Magazine Thu 21 May 2015, 19:04

ACTIVATED CARBON FOR MARINE AQUARIUMS – Part 1

[You must be registered and logged in to see this image.]Activated carbon is a filter material, that has already been used in aquariology for a long time. As much as this material is well known, its correct use and the effects of using it to treat aquarium water are very unclear. The difference in quality between various types is so crucial that every aquarist should test his carbon before using it. It is known that fragments of coral inserted in a calcium reactor can release phosphates. Surely it is less known that also some types of carbon can increase the phosphates in aquarium water.

How does activated carbon work?

Because of molecular forces, substances (gas, liquid, and solid particles) have the characteristic of attracting each other. These attraction forces, called Adhesion, execute their influence on the so-called limit surfaces, such as the external parts of bodies found in the water (carbon filtering), or on the external walls of air bubbles in the water (foam fractionation)(Naser 1986, Kloppel & Kloppel 1980). Naturally these adhesion forces also have an effect on the surface of the aquarium glass or on the ornamental items inside it. The available surface is, however, very limited, and it cannot be replaced when it is saturated. The absorbing ability of carbon, meaning how much matter can attach itself onto its surface, and its speed of absorption depend on several factors:

1 Surface

The surface. The more space is available, the more substances can bond. The surface of activated carbon varies from 400 to over 2000 m2/g. It should also be said, to set a limit, that the smallest pores, called “Sub-micropores”, which have a radius of 0,4 nm ( (1nm = 1 Nanometre = 1 thousandth of a Micrometer = 1 millionth of a millimetre), are not available to bigger molecules. In the field of aquariology, however, activated carbon should be used in the absorption of larger molecules, such as yellowing substances and the residues of medicinal ones. The chemical characteristics of the surface, just as the type and quantity of the oxides on it (groups of Quinone, Carbonyl, Carboxyl, Phenols etc..), also play a crucial role in the absorption process.

2 Temperature

The lower the temperature, the more substances can be stored on the surface. However, the higher the temperature, the faster it can be stored. In aquariology, these rules are not particularly important because the temperature usually stays fairly constant. The aquarist should, however, try to avoid introducing into the aquarium carbon that has been previously used in cold water (for example to filter tap water). In this way, bringing the carbon to higher temperatures, the substances that have bonded to the carbon in cold water can then be released in warmer water. How fast some substances can be absorbed and at which temperature depends mainly on thermal valence factors. (Isothermal absorption) (RAMSCH, B. 1992).

3 Shape

The shape of activated carbon does not have an important role in its performance. The regular-shaped one only brings a small benefit that the fragmented (pieces of irregular shape) one does not provide: it allows the water to flow better through the bag that contains it. Carbon in powder reacts a lot faster. However, its use in aquariology is more complicated (Diatomaceous earth filter) and the time factor is not normally critical.

4 Concentration

The concentration of the substance to be eliminated has a role that is just as important in the rate of absorption. The lower the concentration, the more slowly the substance can be absorbed. Especially in the micro-elements range, long contact periods are necessary.

How is activated carbon made?

Activated carbon is made from the most diverse materials such as peat, wood, soot, bones, blood, bituminous coal, coal, coconut shells, fruit seeds and sugar. As for the quality of the product, the determining factor is the method of activation. Finished activated carbon is composed of 83-93% carbon, and the rest consists in 1-3% of hydrogen and 0,2-10% of oxygen. Nitrogen and sulphur are present only in traces. (Lurgi 1989). One of the characteristics of chemical activation is that the raw material is dry and mixed with chemicals such as: phosphoric acid, sulphuric acid, potassium hydroxide, and sodium carbonate. Through aeration, from about 400° to 600°C, the chemicals extract oxygen and hydrogen atoms from the raw carbon. After washing and then drying, the finished product is ready. The other method to obtain activation consists in steam treatment. At temperatures around 800 to 1000°C, a nitrogen based atmosphere is put in contact with the raw material (C+H2O-CO+H2). Perfect control of the reaction’s temperature and time, just as the concentration of oxygen, carbon dioxide, water, carbon monoxide and hydrogen, influences the elimination of undesired atoms and avoids the combustion of the carbon during this process, determining the final quality and structure. The activation of this material, for the reasons above, is therefore not within the aquarist’s reach. Unfortunately the expression “activation” is used in the wrong way by some sellers, who define it as the de-gasification of activated carbon before its introduction in the aquarium. In several aquariology books the regeneration of used carbon through treatment in the oven is described. These statements make no sense. Usually specialized companies are able to regenerate carbon using the techniques we mentioned. Every regeneration, however, entails an alteration of the pore structure, affecting the quality in a negative way.

Part 2 will follow

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by Coral_Reef_Magazine Thu 21 May 2015, 19:07

ACTIVATED CARBON FOR MARINE AQUARIUMS – Part 2

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What is the correct use of activated carbon?

1 Elimination of oxidising substances from the water

The elimination of oxidising substances does not concern the above mentioned ability to absorb carbon, but instead it involves a different property: chemical absorption. In this process the substances that are able to oxidise, such as chlorine and ozone, are catalysed and destroyed; they accumulate on the surface just briefly and soon after they break up into their main components. To eliminate chlorine from water, for example, just a few seconds of contact are enough. Carbon filters can therefore be small; while a low quality product is usable. Together with modern osmosis systems, a carbon pre-filter should be used, in order to eliminate chlorine and ozone. In this way, the membrane is protected against early oxidation and the resulting deterioration (Sellner & Ramsch 1996). Even when protein skimmers with high ozone doses are used, post-filtering with carbon should always be considered, especially if the osmosis system is installed downstream from de-nitrification filters (anaerobic). In such an environment Redox values increase even up to 700 mV, and the reflux water, rich in ozone, can endanger more delicate animals. In cases where the use of ozone in the system is moderate, carbon filtering is not necessary. During use as we described it, the material does not wear out; however the particles in suspension gradually obstruct the surface, reducing its power as a catalyst. The same can be said for osmosis systems’ pre-filters; when they are dirty, they need to be replaced. The activated carbon that is used for cleaning the protein skimmer’s reflux water should always be replaced in case you identify sediment, excessively high Redox values, or free ozone is measured.

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2 Air de-ozonation

From the protein skimmers in which ozone is used, air containing this gas comes out. The air should always be channelled through a carbon filter to avoid the diffusion of ozone into the environment. Even in low concentrations, (100ng/m3; 1ng=1 thousandth of a milligram) it can cause headaches and discomfort. If you can smell it, the concentration is definitely too high! In large protein skimmers it is therefore advisable to use ozone measuring and alarm equipment. The filters for the protein skimmer’s air should always be checked, because excessively damp or even wet carbon significantly compromises the effectiveness, and the time needed for the ozone to break down increases substantially.

3 Elimination of organic substances from tap water

In some areas, drinking water from the the water main is not suitable for aquariological purposes. Even when the values measurable by the aquarist, such as hardness, nitrates, phosphates and silicate minerals are in the norm, pesticides, residues of disinfectants and hormones can be a danger for more sensitive marine organisms. In this case too, activated carbon can be of help. The above-mentioned substances are, in tap water, only present in micro or nano-grams, but even in these minimal concentrations they constitute a potential risk. To eliminate these substances in such concentrations, for example 100ng/l (1ng = 1 millionth of a milligram), from tap water through activated carbon filtering, the carbon should stay in contact with the water for at least 30 minutes. Unfortunately there are some filtering systems on the market that, according to the maker, are able to purify several litres per minute. These claims are usually followed by rather questionable data. An evident decrease in pesticides, on the milligram range, can definitely be true. In the range of micrograms, however, in these levels of water flow, the provided data are surely unreliable. Therefore, to use activated carbon to filter tap water, the time of contact between carbon and water needs to be very long. If, for example, we use 1 litre of activated carbon, not more that 2 litres of water per hour or 50 litres per day should flow through it in order to get a filtering effect. As for the duration, instead, we should use the provided data as a reference, which unfortunately does not always happen. To be sure, it is advisable to not use the activated carbon for more that 5000 litres of tap water. Beyond this we cannot be sure it has an effective absorption ability. Because of the above-mentioned reasons, it would be appropriate to ask whether it would not be more suitable to use a reverse osmosis filter, which gives better and especially more easily verifiable results, even by the amateur. (Selner & Ramsch 1996).

Part 3 will follow

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Coral Reef Magazine Volume 2