A Shrimp For The Marine Aquarium

The first things that come to mind when considering livestock for the marine aquarium are fish, completely understandable. Then, how about corals for the reef aquarium, very and understandably popular. The aquarium needs to be carefully set-up with seawater quality, inmate life security (no unwanted predators or overly aggressive creatures) in mind, ensuring that cost is acceptable. There will be of course an ongoing commitment to maintenance so that seawater quality and lighting are acceptable. Security (somewhere to hide) is also important, usually nicely provided by the reef rocks. Very often the reef aquarium will be furnished with live rock which, provided the requirements for quality and quantity are met, is an excellent choice. The rocks will act biologically and make the reef, forming caves etc. The aquarium should not be overloaded with fish meaning the biological support is sufficient and the seawater quality is high, helped by sufficient ongoing partial seawater changes. All of the above is aided by the often mentioned simple requirement for research. Ok, so the aquarium is mature and has been running a while, all tests are positive and as required. The aquarist would like to add some diversity being happy with the fish and corals. What about a shrimp?

A colourful shrimp that comes to mind is the banded coral type, proper name Stenopus hispidus. As can be seen these are attractive and assist the image of the colourful coral reef. This shrimp occurs in all the tropical seas of the world and is quite easy to obtain. The shrimps usually live in pairs in a cave or under an overhanging edge often with only their white moving antennae showing. They could grow to about 3″ (circa 7.5cm). Their life span in a well maintained and stable environment is 6 years or so. In the wild they offer a service to fish by removing parasites and dead tissue. As mentioned seawater quality is important and regular testing is needed. A normal temperature of 70 to76deg F (20 to 24 deg C) is suitable and should be stable. If nitrate levels rise higher than 10 parts per million (ppm) it starts to become stressful to the shrimp and as the nitrate level becomes higher the more troublesome to the shrimp it becomes, interfering in the molting process. So disciplined feeding of the fish etc is very important. Salinity of the seawater needs to be constant without serious fluctuations, as the shrimp are sensitive to salinity changes. Therefore partial seawater changes need to be checked before use for salinity accuracy. If possible obtain a known pair of shrimp, they will live together peacably. However, avoid obtaining two males or two females as they will fight until only one remains. The male is smaller and slimmer than the female. Single shrimps of opposite sex can usually be introduced successfully and they should pair up. Feeding the shrimp is usually not a problem as they are good ‘cleaner-uppers’ finding food missed or left by the fish. If they appear by observation to not be getting much then leave a small morsel of food in front of their cave and observe if the action is successful. Excessive feeding should of course be avoided.

Introduction to the aquarium is easy and similar to other lifeforms. The shrimp must not be exposed to the air. The best method is to remove half the seawater from the transport bag and drip feed a replacement from the aquarium using a narrow plastic tube with a controlled slowish drip (be sure that there is not a large reduction in temperature in the bag as the drip process proceeds). This ensures the change in the seawater is gradual and not sudden. Then put the bag into the aquarium and leave for about 30 minutes for temperatures to equalize. The shrimps can then be gently released.

When first introduced to the aquarium the shrimp are likely to hide. As time passes they will be seen more even under the bright lights of a reef system. As time continues to pass and they become accustomed to the day/night process in their world they will be active and seen regularly.

There are other species in the Stenopus range and these too need the same care. Stenopus hispidus is a larger type, a smaller example is the yellow back coral shrimp Stenopus scutellatus which is about 1.5″ (circa 3.5cm). Whatever is kept, it is best that the aquarist has aquarium management experience so that seawater quality is high and can be kept so. The shrimp offers an extension to the captive reef, offering a different but still colourful and interesting life form.

(Photo: tradebit.com)