This group of crustaceans shares some characteristics that help us to lump them into one category. Most of the following species are not too aggressive, and all have there abdomen sticking out behind their cephalothorax (unlike crabs). 

Most of these animals can live well with other members of their species. Their claws are often small, and many species can be sexed, with the males often being either smaller, or having larger claws than the female. All of the shrimps will accept a variety of foods, just try to insure that they can get some food. Try feeding bits of food directly or maybe feed at night for the first few feedings to help the shy specimen along. 

The following is a list of specific genera, and some of their requirements. 

Lysmata This is the genus of the familiar Cleaner Shrimps. They are slender bodied with very small claws. They are social, and harmless. Under good conditions they will actively clean the parasites off fish. 

Stenopus are the Barber-Pole or Boxer Shrimps. They share many with features with Lysmata but they grow much larger, and do best either singly or in pairs. 

Saron and Rhynchocinetes are the genera of the Marbled and Dancing Shrimps respectively. These shrimps share many features and are so lumped together. They are shy and nocturnal, shun bright light, do good in groups, and the males typically have larger claws. The Dancing Shrimps can be displayed nicely by creating a small cave of lava rock, to which the will cling to the inside roof of. Saron shrimps like similar conditions, but will stay on the bottom of the cave, amongst small patches of gravel and algae. Some members of these genera are known to consume certain species of corals. 

Periclimenes is the genus of the fragile and beautiful Anemone Shrimps. They form an intimate bond with a specific anemone or other cniderian. Great care should taken when introducing these animals as they are quite shy and fragile. Provide a host cniderian that closely matches their background color. Once with their host, the will feed from food caught by their host, and do quite well. 

Hymenocera are the curious Harlequin Shrimps. These comical animals do good in pairs, and have a strange diet. They eat starfish. About every 2-3 week a small starfish should be provided, with the genus Linkia (Blue Stars) being the best. Remove the starfsh after signs of decay are obvious. 

Take great care in acclimating your new shrimp to the aquarium. Make sure that you not only consider salinity and temperature, but the habitat and other tank mates. Try to provide the specific niche that your specimen requires. Introduce them by opening the bag (after temperature and salinity are with in acceptable limits) and gently place them near the desired location. Low light intensity, and insuring the other tank mates are not too close or hungry will help these docile creatures out a lot.