Mini Crabs & Fiddler Crabs

Fiddler crabs in the wild can be found scuttling across sea beaches as well as brackish inter-tidal mud flats, lagoons, and swamps.  However, the usual mini or fiddler crabs you can find at your local pet store are semi-terrestrial brackish crabs, which will mean they need some aquarium salt in their water as well as access to occasional air and dry land.  These small crabs enjoy eating flake, thawed freeze-dried, pellet, or thawed frozen foods in captivity - alternating proteins and algae foods.  The movement of the smaller claw from the ground to their mouth during feeding illustrates the crabs' common given name; it looks as if the animal is playing the larger claw like a fiddle!  

 In order to eat, the crab's smaller claw picks up chunks of sediment from the ground, bringing it to its mouth, and sifting through the sand and soil for anything edible before rolling up what is left into a tiny ball.  The presence of these types of sediment balls near the entrance of a sand burrow is a good sign of a crab living there.  Their diet makes Fiddler crabs “detritivores”:  meaning creatures that gain nutrition from eating decomposing plant and animal material.  Scientific research suggests that the feeding habits of fiddler crabs play a vital role in the preservation of wetland environments - by sifting through the sands, they aerate the substrate and keep the soil saturated with air.  

Fun Fact:  Fiddler crabs exhibit a constant circadian rhythm in a controlled setting that imitates the ebb and flow of the tides.  This makes the crabs turn dark in the day and light in the dark!  

Fiddler crabs are most well known for their dimorphic claws; the males have one larger, dominant claw than the other while both females’ claws are the same size.  Fiddler crabs communicate using a sequence of waves and gestures with their claws, but that's not all!  Males also use their claws for confronting other competing males in ritualized combat during mating season or waving during courtship to attract female crabs.  Females then choose their mate based on claw size and also quality of the waving display.  Scientists believe that the male major claw size can also be correlated with burrow width as the width of the burrow influences incubation temperature. Therefore, the female will choose a male mate whose claw size indicates the best fit for the burrow environment for her clutch of eggs. 

Like all crabs, fiddler crabs shed their shells as they grow.  If they have lost legs or claws during their present growth cycle, a new one will be growing when they molt.  If the large fiddle claw is lost, males will begin to develop one on the opposite side after their next molt.  Newly molted crabs are very vulnerable because of their soft shells, so it is best to leave them to molt and recover peacefully.  Don’t be alarmed to find a molting Fiddler crab lying on its back as this is normal!  During a molt and shortly after, they are reclusive and hide until the new shell hardens.  If you leave their shell in the enclosure afterward, though, they will eat the remaining discarded shell for it is a good source of calcium!

Fiddler and other mini crabs require at least a 5-10 gallon tank, with preferably as many as or fewer than 4 crabs per 10 gallons.  

These Starfire Red GloFish Barbs were born brilliant!  Whether you're an experienced fish keeper or a beginner in the aquarium hobby, these GloFish can add zeal to any tank community.  The brilliantly colored little fluorescent fish are friendly, relatively hardy, easy to keep, and fit into almost any aquarium environment with fellow community fish.  It is particularly important, though, to note that GloFish Barbs specifically need to be kept in groups of five or more to keep the fish from potentially becoming aggressive.  Be sure to not crowd your community tank, too, and to not keep your fish in a small bowl or in direct sunlight or heating/cooling sources.

Contrary to what some people may believe, GloFish have not been injected, painted, or dyed; they actually get their lifelong, magnificent colors from a protein gene they inherited from their parents.  Each new GloFish inherits its unique color directly from its parents, maintains the color throughout its life, and passes the color along to its offspring.  Initially, the National University of Singapore utilized their unique coloration to help identify and fight environmental pollutants and toxins in bodies of water to help prevent sickness in local areas.  After an interest was shown in also keeping these fish as pets, they have been bred to pass on their unique and brilliant colors to their offspring, much like many other freshwater tropical species.

These vibrant little guys make a great addition to or stand alone tank for nearly any office, home, or classroom and can make fantastic first pets!  Try "experiencing the glo" with Tetra's Glo Ornaments, Plants, Lighting, GloFish Kits, and tank accessories.  GloFish can be an educational tool for children and provide a fun, interactive way to inspire a love for science and responsibility, all while still offering the stress relieving affects of owning an aquarium.  Want to learn more about these amazing GloFish?  You can also visit and Uncle Bill's near you for more information.  We'd be happy to help!