sera guide - Marine aquariums

18 Gobies like those of the genera Cryptocen- trus, Valencienna, Flabelligobius or Stonogo- biops permanently live together with pistol shrimps of the genus Alpheus. The shrimps have poor eyesight and build caves within the sediment that also serve as a living place for the fish. The fish even guard and supply the shrimps with food in return. These are very dynamic communities in which two completely different animals, fish and shrimp, have developed a way to communicate. This is an excellent example for co-evolution. Set up the live rock chunks in a way that leaves a sandy area for the animals in the front part of the aquarium. You will usually have only a few pistol shrimp (1) species to choose from: Alpheus bellulus and A. randalli. Alpheus bellulus is the much more active species that lives together with larger gobies (2) such as Cryptocentrus cinc- tus. Females have a much broader abdomen than males. Gobies of the genus Stono- gobiops usually live together with the red and white Alpheus randalli shrimps. A small live rock chunk placed in the center of the sandy area forms a first hideaway for the gobies and shrimps. Ideally, you can dig a little hole underneath the rock chunk with your finger. Add the animals one by one in a glass. Slowly turn the opening of the glass towards the bottom and place it upside down precisely in front of the rock chunk, where the hole is. The shrimp will immediately enter it and start digging. Proceed in the same way with the second shrimp. You can add the go- bies to the shrimps about one hour later us- ing the glass. By doing so, the gobies will find the shrimps much faster than if you just put them somewhere into the aquarium. The fur- ther setup can be done as soon as the center part of the symbiosis is established. Please read chapter 8 before adding the aquarium inhabitants. You can put the shrimps and go- bies into the glass with a fish net and then proceed as described above. 2.3 Biotope: Gobies, pistol shrimps 1 2