The Mangrove Aquarium

By Cees de Snoo (Pets and Ponds)

First let me introduce myself, my name is Cees de Snoo (pronounced Case the Snow) I’m dutch, and 52 years old. In the house where I was born there was already an aquarium and I got my first one myself when I was 6 years old. Fish-keeping never let me go and until now I have always had an aquarium. At a very young age I became a member of the A.V. Ciliata, our local aquarium keepers club. Automatically you are a member of the national aquarium and terrarium society’s, they organize meetings, competitions etc. In Holland, Germany and Belgium the hobby is very big and every town and city has several specialized aquatic shops. About 25 years ago I saw in a shop some unusual fish, the mudskipper. This is a fish which can live outside the water for a while. They take some water in their gillbags and close them. Also they have converted breastfins which look like legs, for the rest it is a brown little fish with some stripes over the body. You can recognize them by the stripes and the colour of the backfin which they use for signalling to each other. Immediately I fell in love with these fish and bought them. As good as possible I decorated an aquarium in the mangrove style, their natural habitat. Reading and contacting other mudskipper keepers (there was no internet at that time) the imitation of their habitat became closer and closer. Brackish water, stilt roots and a big land area are essential for their wellbeing. The secretary of our club persuaded me to enter the club competition with this aquarium, reluctantly I agreed although I didn’t think my tank suitable for the competition because of the lack of plants. The aquarium was judged by the society examiners and I was shocked that the tank was not only the best in its category (specialized) but also best of the club. Next step, the county competition. This was a tough one (150 tanks) and the examination more painstaking. I became third in the category and tenth general. And I was as proud as a peacock. The comments made in the judging process were quite helpful and constructive and made me think of ways to improve further. To my surprise everybody was amazed by this new concept, the mangrove environment.

Bigger and Better…

My job forced me to travel and I had to do a lot of courses to improve my status at work, so for a couple of years, aquarium keeping was on a low profile. The opportunity came then to change my job for one that gave me more time at home, with more normal working hours. With a friend of mine I visited an aquatic shop and there I saw them again, my old love, the mudskippers. My heart start to beat faster and the longing came back again. Immediately I called a friend that I knew had an empty aquarium, and the shop owner was willing to keep them for a week while I set up the tank. This was very basic, a land part with stones and roots, and a strong pump to create water flow. But this time I was determined to get plants and fish from a brackish mangrove environment. Fish was easy, but the plants were another challenge. Don’t believe everything that is written in the books, I spent a lot of money and time on plants that according to some authors can have some salinity and they died even with a small amount of salt, while trying to let them get used to it.

Cryptocoryne ciliata, Ammania senegalensis, Bolbitis heudelothi and a plant I found on the Dutch shoreline survived and got taller. Cr. Ciliata became so tall that I had to remove the lid from the tank. In the city of Arnhem is a zoo called Burgers zoo and they created a mangrove hall, Needless to say I went up there and contacted the keeper, and told him my story. He was very enthuasiastic. He called the curator and he came to talk with me. We spent an hour talking, so at the end I went home with some real mangrove plants and propagulae. I was over the moon. As a favour in return I promised him to look for some special fish and crabs, and nurse some of the delicate fish species. The plants where: Aeghiseras icilifolium, the mangrove holly, Conocarpus erectum, the dwarf mangrove, and the propagulae ( the “seeds”) of the white mangrove Avicennia germinans. They were placed in a tank with the same salinity as the zoo 1.003 to nurse them.

It was easy to convince my wife that we needed a bigger tank with no lid to create a real mangrove aquarium. There was a spot in our house very suitable for it and after some drawings we went for it. The size was 220x 75x 75 cm, because there was no top support the glass was 10 mm thick to cope with water pressure. I had no worries on that score though, because the depth of water in the tank was only 30 cm.


Dutch punctuality

The tank was specially made for me at an aquarium manufacturers in Holland to my requirements and it was terrific, there was only one problem. A tank of 220 x 75 x 75 wouldn’t fit through my front door! What to do? My wife and I decided that now was the time to replace the single glazed window of my living room with double glazing.
I ordered the double glazing for the window and the fish tank to be delivered on the same day. At 9am on the dot the glazer arrived and removed my front window pane. Then he said to me ‘where is this big fish tank?’ Right behind him the aquarium delivery man said ‘Here it is!’ It took six men, three of us outside in the garden and three in the room to get the tank in through the window and into position on the cabinet and then the glazer installed my new double glazing. Problem solved.
To stay in the same style as the decoration and interior of our house I had made the cabinet from red/brown bricks and oak panels and doors. I was careful to ensure it was very sturdy because of the weight it had to hold. The background was a project on its own, I constructed it out of polystyrene and tile grout with a brownish grey colour like a mudbank. It took me 3 weeks to complete the background with all the filter pipe work covered. Placed in the aquarium it had to dry out for a couple of weeks, and that gave me the time to search for the fish I wanted to put in it.

On the wish list were of course the mudskippers, archerfish, bumble bee gobies, pseudomugil species, and if I could get them, the four-eyed fish ‘Anableps anableps’. From previous experiences the mudskippers must be the species ‘Periopthalmus septemradius’, a small and easy with other fish mudskipper, and not the ‘Periopthalmus papilio’ which is easier to get, but which is very territorial and aggressive (once I cleaned the aquarium out and a male came for me, he bit me in the thumb and they really have teeth!).Bumble bee gobies grow bigger and colour more in brackish water than in fresh water and are very peaceful. Archerfish can shoot a drop of water out of their mouth to hit flies and other insects, and they live in the mangrove swamp.
Pseudomugil species also live in and around the mangrove and even in the sea, this is a fish which belongs in the family of the rainbow fish.
About the four eyed fish, ‘Anableps anableps’ together with the mudskippers they were a MUST HAVE, this fish belongs to the family of live bearers and has eyes that can see both under and above the water line. A typical surface fish, they grow about 30 cm. In the wild they migrate from fresh to sea water and back again with no problems at all.
Most of the mangrove dwelling fish have this ability to adapt to both fresh and sea water without osmosis problems. It took me about a year to get all the fish. I also got some very rare killi-fish, the ‘Rivilus caudimaculatum’, which bred very successfully in my aquarium. Again the board of the club pushed me to enter the club competition, this is always good craic and encourages you to keep your aquarium in tip top condition.
Points are given for every part of the tank e.g. technical setup and lighting, condition of the fish, condition of the plants, water quality, the compatibility of the fish together, the contrast of the plants with each other in colour and leaf to create a pleasing vista. Points are also given for the overall success of the environment that you have attempted to create.
The examiners came to my home and they were surprised to see a mangrove setup. Asking me everything and writing down things. Taking water samples and photos. As you may read they took it very seriously. The results are announced two months later on a Saturday evening. Slides are shown of all the competitive aquariums with an explanation how they are set up. At the end of the evening the results are given.
The results start from the lowest to the very top. Names were called to receive their ranking and receive comments on how to make their aquariums better.
There is always a mini break before the remaining three highest places and I was among them, I couldn’t believe it! The glass of beer was shaking in my hand and my heart was in my mouth.’ It can’t be’, I thought, ‘the other aquariums are so much better and the keepers so experienced with competition’.
The M.C. called us in for the final results, the three of us had to come forward and the judge told us that there was so little points difference between us and the aquariums were of a very high standard. A name was called AND IT WASN’T ME!!!
I almost faded away, the examiner started again saying how high the standard was of the second best aquarium and how much time and effort was used to create such an aquarium. ‘Hurry up you f****r’ I thought. The tension was unbearable, the name of the runner up was called and I was the last man standing. Club champion with my new aquarium, unbelievable. The difference between 1 and 2 was 1 and a half points. Congratulations and celebrations went on deep into the night. Up for district championship, the winner of this to go for the national championship. Other judges and stricter examining rules here. I ended up third place but I was still proud and happy. One remark on the results list stayed in my mind though “because there is no tidal influence which is obviously part of the mangrove system, we cannot give you the full amount of points for environmental creation.”

Flowing with the tide




Not that I was obsessed by the idea of a tidal effect in the aquarium, but it was on my mind. First I put the plan on paper and went through all the possibilities. The trick is to work out on paper all pitfalls and failures before you construct the actual installation. Also I must have a safety plan to prevent the aquarium emptying itself all over the living room floor. It was constructed in such a way that there were three safety steps, so no screaming and yelling spouse that the whole house was flooded. The next step was to find components to build the installation, it included pumps and time switches, hydraulic valves, regulator taps, and a big barrel which could contain all the water from the aquarium. I took a few days off and started to build. It took a day or two but then the installation was ready for the test. A few leaks solved and then it was the time to regulate the time to make it low tide, dead tide and high tide. This took the longest time to get right, because, as in nature, it must go slowly. There was an interference built in so I could start or stop the cycle at any time when necessary. There was 30cm of water in the tank at high tide (5 hours) and about 10cms of water at low tide, but still plenty of water for the fish. At low tide which lasted for 5 hours or so the mudskippers came out onto the banks and searched around for food. The tidal flow took about 1 hour to run in or out of the tank. So you can see as in nature the tide rose and fell twice a day. The system never let me down and the fish loved it.


  1. From Aquarium to filter Pump
  2. From Filter Pump to Aquarium
  3. Flow Adjustable Taps
  4. Hydraulic Valve normally closed
  5. Time Switches
  6. Ball Valve
  7. Filter Medium
  8. Pump Return to Aquarium

As you see on the drawing the concept is not that complicated, but that is what the secret is, keep it simple. The components are made from plastic or stainless steel to prevent corrosion by the salt in the water, and of course there was some maintenance involved like cleaning and controlling working parts such as the pumps and valves.


Happy Families

The mudskippers loved the tidal influence. They were constantly roving around the dry banks looking for something to eat and I fed them always on low tide. But also the four-eyed fish the Anableps came out of the water and ate together with the mudskippers. The food was a variety of bloodworms, chopped mussels, earth worms, etc. Crickets and curly winged flies were on the menu for the archer fish, and Daphnia for the bumble bee goby and other small fish like Pseudomugil gertrudae . With this menu the fish grew fast and were very healthy.






The Anableps group reached maturity and started to mate, this was unique because, according to records it is very hard to keep them alive and breeding them was almost impossible. In my aquarium they grew up to 20-25 cm. Two males and five females. There is a kind of tricky thing about mating with the Anableps, they are livebearers like guppys and platys etc. But on the contrary to other livebearers the males can only bend their gonopodium to one side and the females are only receptable on left or right side. Conclusion, you can have a male and female but if they don’t fit together, you will never see any young fish. To my luck the males were one left and one right, and the females three left and two right. As the time passed by, the female’s bellies started to be thick and swollen, so I thought there must be something happening. I will never forget that Saturday morning, I woke up and made some breakfast, with a cup of coffee in my hand, half sleepy. I looked in the aquarium and saw an Anableps female laying on the bank, out of the water making strange movements. Was she ill? Or hurt? And a lot of blood around her! What was wrong? Then my eyes flew wide open, a young fish popped out of her! It lay on the bank for a few seconds and then waggled into the water. Immediately I inspected the aquarium and found three young Anableps between the stilt roots as big as a full grown female guppy and about the same colour. Five in total, and already swimming around, the other fish didn’t seem to mind. To be secure, the youngsters were put in a spare aquarium with a land bank for them to climb on, I didn’t want to lose these precious little fish. On the third day the yolk sack was consumed and immediately they started to eat Daphnia. Subsequently they were moved back to the large aquarium when they were old enough.


Fame at last!

Delighted with my breeding success, I contacted the secretary of our fish-keeping club. ‘I’ve got young four-eyed fish’ I said to him. ‘Are you still drunk,’ he replied, ‘that’s not possible, they’ve never been bred in captivity to my knowledge.’

He arrived on my doorstep very shortly after, to check out my wild claims.

Staring into my tank he couldn’t believe his own eyes. Immediately he got out his phone and rang the head of the N.B.A.T. ( Nederlands Bond Aquarium Terrarium Keepers) the umbrella organisation of our club. He didn’t believe it either and asked me to take some pictures. We did this and sent them over to him. I also sent them to the curator of the zoo I got the mangrove plants from.


This really started it all, I was invited to give lectures and readings and also asked by several zoos to talk about my experiences. Needless to say, they were all very keen to have some fish from me. All the fish flourished in the aquarium and even the bumble bee gobies had eggs and fry. The mudskippers never bred and when I ever have an aquarium like this again, this will be my aim. Through the years the Anableps bred so well that I eventually had fish seven generations descended from the original wild caught ones I started with. I was able to keep away from inbreeding because there were four different bloodlines .You can tell one fish from the other, the lines on the tail show for every fish a different pattern, so I drew this down and could tell you which fish had which parents. Like a pedigree. I had great success also with the aquarium competitions. The crowning achievement on my work was that this aquarium reached the very top in 2002. Best of the club, best of the district, best of the county and number five in the National Competition. Nobody laughed anymore about this tank filled up with mud

Sad Goodbyes and a New future in Ireland.

Great was the shock when I told my aquarium-keeping friends that we had made plans to move to Ireland. The club arranged a goodbye party for my wife and I (she is very keen in keeping terrariums, with her speciality poison dart frogs from South America she reached top rankings in the competitions.) On that occasion I was honoured with the Silver fin, an award given to people who did break-through or scientific work for or in the aquatic world. My house was sold then before the move, my beautiful tank dismantled and all the fish went to several zoos (Blijdorp Zoo Rotterdam, Burgers Zoo Arnhem, Wilhelma Stuttgard.)

Some day I will build the whole thing again, bigger and better, and then maybe breed the mudskippers as well.




For further information or to ask questions

Contact me at my shop ‘Pets and Ponds’ Unit 27 Dungarvan Shopping Centre, Dungarvan, Co. Waterford.

Phone 00353 (0)58 40158



© – November 2008