The Cleaner Shrimp

One of the great advantages of running a marine system is the different types of livestock that could be housed. The diversity in the aquarium will never equal or come near that on the wild reef, but there is enough to create a great deal of interest.

In addition to various types of fish, there are snails, crabs and shrimps. The aquarist has to be sure any of these additions are safe – ‘safe’ in this instance means they will not damage or eat other livestock, and in turn other livestock will not damage or eat them. For instance, some crabs are not welcome as they blunder about the aquarium and knock things over or even attack and damage corals, and similarly some shrimps are not welcome in an aquarium with starfish as they will attack and eat them. Likewise a shrimp placed in an aquarium with certain fish is in great danger of being consumed. However, many snails are of use in the control of algae and some hermit crabs can be of use as general housekeepers.

There is a shrimp that is very often the first ‘diversion’ from fish that a fairly new aquarist with a reef aquarium will be attracted to and this is the cleaner shrimp, properly named Lysmata amboinensis. Have a look at the shrimp via the link:

http://www.oceanlight.com/lightbox.php?sp=Lysmata_amboinensis

It is commonly called the cleaner shrimp because of its fish cleaning actions on the wild reef. The shrimp, with a number of its namesakes, set up a cleaning station on the reef which becomes well known to many fish of all sorts. The fish will even patiently wait their turn if the cleaners are busy. These fish come to the cleaning station so that the shrimps can remove parasites, growths, loose scales and other irritants from the fish’s surface. The little shrimps even go inside the gills and mouth of the fish with the fish ‘opening wide’ to permit this. It would be a quick snack for the fish but presumably they recognize the shrimp from its markings and movements and let it be. I read of an experiment on a wild reef where cleaner stations were removed from a specific quite large area and the incidence of problems such as fish disease increased. When the cleaner stations were re-introduced the problems diminished.

If the shrimps are to be introduced to the home aquarium it is important that they are acclimatized properly. This means that seawater in the transport container is reduced by half and seawater from the aquarium is dripped into the container using an air line and air line clamp. The drips should be a little short of a continuous stream and the container allowed to fill to its previous level. Some aquarists then repeat the process. The shrimp should not be exposed to the air. They settle in quickly. It goes without saying that the aquarist must be sure there is nothing already in the aquarium that could threaten the welfare of the shrimp. The shrimps can be kept as a group if required.

The shrimps soon become a favourite pet as they quickly respond to the presence of the aquarist – expecting food no doubt – and will climb on the aquarist’s hand if this is in the aquarium. They probably see the hand as a fish and proceed to move about on it looking for food. Feeding them is easy as they will accept directly offered small pieces of de-frozen food such as lance fish and mussel etc. They will even attempt to capture pieces of flake food and can learn to be quite successful.

In the aquarium they may attempt to clean fish as they would on the reef but this may be an irritant to the fish. In the aquarium the fish cannot move away from the ‘cleaning station’ but usually they move away far enough and trouble does not arise.

The shrimp is ‘reef safe’ and the reef system is the place for it to be housed. Being in a reef system also allows the shrimp to molt securely. Molting is when the shrimp casts off the old exoskeleton and hardens off a new one. This occurs as the exoskeleton does not grow so the shrimp from time to time needs a larger one. If a ‘dead’ shrimp appears it could well be the result of molting.

The cleaner shrimp described is not the only one as there is another that is very similar in appearance. This one is properly called Lysmata grabhami. It displays the same colour pattern except that the white marks on the ‘tail’ are missing – the white line that runs down the top and centre of the body extends to the end of the ‘tail’.

Once established in the aquarium, which does not normally present any problems, the little shrimps are super. Not only are they colourful and a contrast to fish, they are very likeable because of their amusing and friendly antics.

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The Dancing Shrimp

There are a few shrimps which find favour with aquarists; some of them have been the subject of other texts on this website. This is another favourite, both for its colouring and character.

Before starting, a picture is needed:

http://fr.reeflex.net/tiere/1019_Rhynchocinetes_uritai.htm

This shrimp comes under a few common names which could lead to confusion: dancing shrimp, rosy dancing shrimp, camel back shrimp and common dancing shrimp being some of them. The proper name is Rhynchocinetes uritai.

They’re lovely to look at and one of the common names – ‘camel back shrimp’ – refers to the clear hump on the back. Another common name – ‘dancing shrimp’ – refers to the jerky way in which they move.

The shrimp is social and can be kept in a group. They do not usually have any trouble with other commonly kept shrimp except perhaps the boxing shrimps, Stenopus sp. Obviously the number kept depends on the size of the aquarium – two could be kept in a relatively small system.

The best habitat for the shrimp is a reef aquarium as this affords all the crevices and caves that are needed. There shouldn’t be any other livestock that could threaten the shrimp of course. Keeping the shrimp in a reef aquarium does have a potential drawback though, and that is the shrimp could ‘have a go’ at soft corals, including colonial anemones. Then again, many aquarists do not have this problem. Hard coral types are usually left alone.

There is another possible advantage to having these shrimps. Please note the word ‘possible’. This concerns that unloved nuisance of many aquarists aiptasia. These anemones are often introduced on the rock of a new coral, or with live rock. After a time during which the anemones spread, an ongoing battle usually takes place between the aquarist and the anemones. This battle usually ends with the aquarist being in control generally but having to periodically re-attack. An uneasy truce could describe it. There have been anecdotal reports on the internet that these shrimps attack aiptasia, mainly young ones. It has also been reported just as often (to my knowledge) that the shrimp ignore the anemones! I haven’t seen any reports following controlled experiments. Perhaps they will, perhaps they won’t.

Generally the shrimps are more timid than other commonly kept types and avoid the bright light of a reef system, initially anyway. They should settle down and be seen more often, though they usually retain their preference for dimmer light. It is more unlikely that they will rise to take food so the aquarist may have to target feed the shrimp. This is not difficult, not least because they will take the usual fare such as de-frozen lance fish, mussel etc. They may well chase brine and mysis shrimp that have been released as food.

As with other shrimps they will shed their exoskeleton from time to time. This is to permit growth. A new exoskeleton will harden over a fairly short period and the old one looks like a shrimp albeit a dead one.

All shrimps need careful acclimatization to the new home aquarium and it is reported that this one is perhaps more sensitive. Therefore transfer to the new seawater should be completed with care. Empty out half of the seawater in the transport container. Then, using an air tube and air tube clamp, drip aquarium seawater into the container until it reaches the previous level. The drip rate is a little short of a slow continuous trickle. It is probably worthwhile carrying out this procedure twice. When the shrimp is introduced to the aquarium it must not be exposed to air. It is also worthwhile switching off the main lights for a day – this period will not harm any corals.

The dancing shrimp in the proper habitat is a delight. They will probably not be seen as often as other types. For those aquarists who battle the troublesome aiptasia wouldn’t it be great if all the anemones disappeared. No guarantee though.

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