Cooler Marines - the temperate Atlantic species
by David Hallett
Fish keeping is one of those hobbies where you have no idea where things are going to lead. Who would have guessed that turning an old hamster home into a fish tank would lead on to a 4' community tank? Who would have thought that 4' community tank would turn into 2 and then of course the breeding tank and the fry raising tank and then the 5' tank and then the 700l and then more fry raising tanks and then of course the children leave home and they pick up the same bad habits, well that's roughly where I am. Its all my father's fault. Of course he blames his father who also kept fish :). My own hobby has now grown to the point where I currently have 15 set ups. Amongst my favourite is my Malawi biotope tank. It was during searching for species information for this tank that I came across the MCH, such a wonderful source of information, which helped greatly when setting up my tank. The time came when I felt the tank was ready to submit it for review in the hobbyist gallery. During one of the e-mails exchanged at this time, I mentioned that the site had inspired not only my Malawi tank but had also encouraged me to try my hand at native marines, although I do not live on the med, I live on the somewhat more temperate south coast of Britain.
I live just 5 mins walk from the beach here in Torquay 10 metres from my front door you can see the sea. I have grown up playing the rock pools and swimming in the sea, catching crabs etc, so I knew there was a bit of life in the local rock pools, but it was only once I began searching for information that I discovered just how many life forms there were in our local waters. Half of which I thought maybe didn't live in Torquay, how could they, I had never seen them. Of course I was wrong I just didn't look close enough.
Local Macroalgae can be impressive, too.
Whilst searching for specimens in rock pools (unfortunately I am not a diver) I realised that our rock pools are teeming with fish and inverts. How could I not notice them when younger? Blennies, Gobies, Sea scorpions, flatfish, eels. Crabs of many different species, starfish, anemones, shrimp, copepods, sponges, tubeworms, mussels, limpets, barnacles and many different snails most of which I had ignored as a child. I had read about the difficulty of keeping marine systems and the expense of the equipment necessary, I simply didn't have the money required for such an experiment.
Lipophrys pholis in my tank
I decided that sometimes risk have to be taken, so I read what I could about marine keeping and forged ahead without a skimmer, uv filter, ozone system redox meter, kalk stirrer kalk doser, oxygen probe, etc etc etc etc. I decided to apply good old fashioned fish keeping logic, and set the 18l tank up using natural sea water and rocks, with a bit of kelp rescued from the surf to do the denitrating. Amongst the rocks were tube worms and barnacles etc etc.
When the tank was setup I felt sure there would be an immediate ammonia or nitrate surge, which there wasn't, so I waited a couple of days, and still nothing, however the tank was absolutely fascinating, watching barnacles open up and extend their legs, I had never even known they had legs. The tube worms of who I had only ever seen the tubes, suddenly poked their heads out. Lots and lots of life was running around this newly set up tank. A short time later my snails decided it was time to breed and laid eggs all over the rocks, which I thought was a bad thing, I thought they were a plague like FW snails can be. So I removed them. (This is something I regret now) The next additions were a limpet and a mussel, no I always knew mussels had to have something inside them but nothing could have prepared me for the shock of seeing it walking around the tank with its little leg and climbing over rocks etc. amazing, they were always just pretty blue shells to me, not something that went for a stroll round the tank. And the limpet, I didn't know they could move, this one was also a wanderer.
One walk along the beach that was particularly fruitful was the one which provided a large (1") specimen of hermit crab (Pagurus bernhardus). Another provided two blennies, which even compared to a cichlid displayed amazing intelligence and personality. The blennies (Lipophrys pholis) unfortunately did not live their full life span :(, one died due to a delay in transferring them to a new tank, the survivor died later on when I lost all my marine fish due to an extended power cut :(, but during the many months that I had these fish they became quite tame, and displayed the sort of personality expected of a cichlid, with hand feeding, and the way they came up to the glass happy to see you, a marvellous fish, I will have another one some time. I also by accident managed to catch several baby fish that I hadn't actually seen amongst sand etc scooped when catching other life. There was a baby sea scorpion (Myoxocephalus scorpius) and two baby flat fish one of which was a transparent form. Unfortunately at under 1cm length they were quickly eaten by the blennies.
I have had a few other surprise residents turn up in the tank, usually with water changes. Including several type of small jellyfish, one type that I identified as a variation of the moon jellyfish, these never lived longer than 48 hours though, I suspect because of the air bubbles from the under gravel filtration. But maybe one day I will set up a tank for them and try to keep a jelly fish. I have also had baby shrimp come in with the water change, one time I had over 100 but they were promptly eaten by everything in the tank, none survived, even the anemone and bigger shrimp joined in the feast.
Anemones are fascinating animals, the beadlet anemone (Actinia equina) at low tide resembles either a small blob of jelly attached to the rock or depending on species a overripe strawberry attached to the rock. However all this changes once the animal is back under water, the animal then retracts its outerskin and extends its tentacles, and its mouth, the colouration displayed when open is amazing, the beadlets themselves range from red to bright green in colour, their mouths are generally hot pink in colour whilst the beads anchorhagi that they get their name from are nearly always neon blue in colour, these animals are quite easy to hand feed just using tweezers tease the food over the tentacles and they immediately grab the food and pass it from tentacle to tentacle and then into the mouth.
Actinia equina in my tank. This particular anemone has already produced "babies" in captivity
I have seen the snakeslocks anemone in captivity but have yet to find one in the rock pools, these are stunning anemone with long white tentacles with purple tips from the symbiotic algae they host.
Palaemon elegans - from the Mediterranean to the Atlantic
My local shrimp (Palaemon elegans) are much the same as the Mediterranean species very hungry, very hard workers, will turn to cannibalism when food gets scarce. They gain a most pleasing fluorescent green outlining when kept at tropical temperatures, I believe this species is sold in the states as a ghost shrimp, I currently have a breeding pair in my tropical marine tank, and have had one large batch of babies which start as planktonic larvae and eventually turn into baby shrimp, my first batch lived for a good 5 weeks into the shrimp stage before losing them for reasons unknown, predation if suspect no1 being as I have a Long Nosed butterfly who refuses to eat frozen food and has to live of copepods in the tank etc so as soon as he came across where the brood were hidden he may well have had a feast. The shrimp are now living in the sump with caulerpa where I hope they will breed again soon.
I definitely wish to keep a cold water setup again to keep the more difficult temperate species as well, I personally find temperate marines to be more interesting than tropical marines but far less colourful, although I have some found pictures of fish and corals which rival tropical marine species. Of the South Coast of Britain we do have corals, although not large reefs, we have trigger fish, sea horses and some beautiful wrasses, all of which I hope to attempt keeping if ever I can afford to start diving. Another one of my desires is to keep the cuttle fish, which is a relative of the octopus, amazing animals again, such variety. Most marine life in the south west is best kept at up to 19C however some species are capable of thriving at temperatures of up to 28C.
Partial view of my previous tank
The filtration system which my 800l tropical \ native marine setup is running is based on a combination of several ideas, mixed and matched to give me the best combination of high water quality natural plankton population, and low startup cost. After much study and experimentation the filtration system which I run is as follows:
5x2x2 tank drilled at the bottom in back with 2 x 1.75" holes with 1.75" pipe running through a 90o bend then straight pipe to the desired water level in the tank. The tank also has a 1.25" hole drilled at the top on one side to which the sump return pump is connected. The outlet pipes being designed so as to allow me to temporarily lower the water level in the tank for maintenance by merely turning the pipe towards the centre of the tank. Using this method I can empty the water level down to about 4" and still have the tank running (although this would flood the sump spare capacity) the water enters the sump from the two different pipes in separate locations, one end enters on the left side where it goes into a chamber full of caulerpa algae and a natural sand \ laterite bed which is lit 24 hours to promote caulerpa growth. The water flows from this section through a debris trap and then into the heater section with the return pump. The second pipe which handles approx 30% of the water flow goes straight into the heater \ return pump section to be heated and returned to the tank. Within the tank there are a series of 5 undergravel filters running with large powerheads pointed towards rock with the tank and corals etc, These provide great flow within the tank as well directing the nitrate laden water from the under gravel filtration directly into the live rock for denitrification. Within the tank is approx 70Kg of rock of which only 8kg is purchased very high quality live rock, the rest of it is dead coral rock purchased at a very very low price, and allowed to be colonised naturally, this rock is covered by filter feeders and sponge as well as polyps and small coral colonies. Nitrification is handled by both the live rock and the UG filter, denetrification is handled by the live rock and the caulerpa algae growing in the tank and the sump. 24 hour lighting on the sump helps prevent caulerpa crashes as well as stabilising pH overnight
The sump return pump is the Ocean Runner 6500 which as its name suggest turns over 6500 lph, huge amounts of power which the corals really appreciate, in total the tank turn over is around 13500 lph which although not as much as I would want is adequate at the moment.
The current fish stock list is as follows
1 Purple Tang
1 Cleaner Wrasse
1 Powder Blue tang
1 Long Nosed Butterfly fish
Breeding pair gold stripe maroon clowns
Breeding pair mandarins
1 Regal Tang
1 Majestic Angel
This may seem like too few for the number of litres, but I feel it is about right it allows an easily maintained stable marine aquarium, I prefer an understocked tank, and like to keep an eye on individual fish rather than be lost in a blaze of colour, I also believe that understocked tanks are more stable and the fish are happier, as long as the tank is big enough and they have enough fish to make them feel confident.
Current Water Parameters
Nitrite Trace (I don't know why but most marine tanks seem to come up with traces of nitrite)
I do keep my salinity a little lower than sea water as I have read that this lowers the chances of whitespot outbreaks which with tangs and butterfly fish it is important to keep them whitespot free.
Lighting is by 250 watt Metal Halide (from electrical suppliers not aquarium specialist) 1xactinic tube 1x 20k "deepwater" tube and the sump is lit by a triton tube 24 hours a day.