Aquarium Livestock Pet Care Guides


Natural Habitat


Tank Temperature




Specific Gravity


Tank Requirements

Provide pristine water conditions; regular water changes & trace elements required for proper growth.


Varies with species. Includes herbivores, carnivores, omnivores, scavengers, and filter-feeding planktivores.


Varies with species. Some aggressive species may prey on inverts and small fish. Many species are fairly reclusive and will hide in the substrate or under/within rockwork.


Varies with species. The temperament and aggression of individual crabs and species varies. Research choices carefully to avoid potential conflicts.

Species Overview

Crabs are found worldwide in almost every environment, including saltwater, freshwater, brackish water, swamps, marshes, sandy beaches and even in some forests and terrestrial environments. There are thousands of crabs species worldwide and their sizes can range from under one inch across to an astonishing 13 feet in some deepwater species. While aquarium species do not grow quite so large, sizes still vary greatly and are far too numerous to include in one simple care guide. The crabs available to aquarists include the "true crabs" from the order Decapoda ("ten-legged") but also include other crustaceans like hermit crabs, porcelain crabs, horseshoe crabs and many others.

Research your crab choices carefully. For as much as they vary in appearance, they also vary greatly in behavior. Many crabs are scavengers and/or algae eaters and will spend most of their time exploring the aquarium in search of food. Others form interesting relationships with other inverts such as urchins, anemones, and corals through which they gain security from predators and close proximity to bits of food lost by their hosts. There are also many crabs that are predatory in nature and that may be destructive in some aquariums. It is very important to know as much as possible about crabs before they are released into a rocky tank where some can be next to impossible to find and remove.

Crustaceans benefit from iodine and mineral supplements to help form a healthy, hard exoskeleton. Regular water changes with high quality salt mixes usually provide enough, but extra supplements may be needed in reef tanks or in tanks with heavy invertebrate loads that use up iodine and other minerals rapidly.

We always suggest that you do further research before adding a new pet to your tank. What we have provided for you are guidelines and suggestions. If you have any further questions or concerns, please contact our fish room at 717-299-5691 ext. 1213 or

Recommended Items

Frozen Aquarium Food
Live Rock
Calcium & Reef Building Supplements