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A QUICK 10 GALLON PALUDARIUM FOR CRABS :

 

On November 5th last year, I decided to put together a quick and dirty paludarium as a grow out for a handful of Red Devil crabs I had caught from my main tank. The tank’s been really easy to care for, and is way more pleasure than work, so I thought I’d share some photos of the build and growth.

 

I used materials I had left over from previous projects: plastic eggcrate, window screen, some driftwood and gorilla glue, some left over ecocomplete cichlid substrate, the end of a bag of ABG mix. And I inserted a Grow Panel as the back wall to give myself an extra step up and pocket of soil, up off the waterline.

 

It was a really quick and simple build. I threw together a false bottom with eggcrate and zip ties. I wrapped it in window screen and attached with zip ties. It was placed into the tank, and the driftwood was attached with dabs of gorilla glue. Leaf litter was added to hide excess glue and cover some corners where the window screen would be left exposed.

 

 

Grow Panel inserted, wood glued to false bottom.

Grow Panel inserted, wood glued to false bottom.

ABG Mix is added

EcoComplete Cichlid substrate and water added

MORE PHOTOS INSIDE 

 

Once the glue had set, I added the ABG mix behind the driftwood, and added the eco complete around the edges of the land, trailing into the water area and forming the underwater substrate. The whole process only took 3 hours from start to finish.

 

I added moss and plant trimmings from my other tanks, and topped it with leaf litter. The substrate was seeded with isopods and spring tails using soil from an existing tank. I added about 9 tiny baby crabs over the first week.

Ready to plant 

Ready to plant

Grow Panel filled and planted

Taken February 6, 2014

In bloom just in time

Taken April 9, 2014

I mist the tank 2 or 3 times a week at the most, and feed fruit flies and bits of crab pellets, repashy soilent green, banana, and frozen blood worms two to three times a week. The crabs are shy, I rarely see them. But I do know they are there, they’ve made clear burrows, have favorite hunting spots and hides. I think they hide more in smaller enclosures. They seem to have very keen eyesight at this age, and hide when I move at my desk, over 6 feet away.

 

 

Semi-Aquatic crabs species : 

 

1- Fiddler Crab :

Three female fiddler crabs above.  Male below.  Shells an inch across.

 

 

The fiddler crab is also referred to as a mini crab. The species thrives best in water that is slightly brackish and in an aquarium with an internal filter. Mini crabs will grow to up to 2 inches. They are usually peaceful crabs that are fairly easy to care for; they can be quite interesting to watch while they are scavenging for food. Fiddler crabs spend most of their time climbing and hiding in driftwood, rocks and other decorations on the aquarium floor.

 

Origin  :  Florida marsh lands mostly

Maximum Size  : 1.5 inches plus claws

Longevity : 1.5 years

Housing : Prefers about a square foot

Security : Digs tunnels or burrows under anything

Temperature : Prefers 75 to 82o

Attitude : Likes to climb

Foods : Beach combing scavengers

Water : Needs clean water

 

Name:  “Uca” comes from the name the local Seminoles called the little scudders.  We call them “fiddlers” because that big claw the males wave around looks exactly like the 1684 Stradivarius mini-violin that Antonio Stradivari made for his second son – the one who played second fiddle.

Male fiddler crabs can be left-handed or right-handed.

Origins:  These crabby little guys inhabit the shores of Florida. Their scavenging helps keep Florida’s coasts clean.  Fiddler crabs eat algae in the wild.  Anything you give them will be more nutritious.

Female fiddler crabs are usually smaller than the males.

Like to Climb:  Male fiddler crabs seek out high points in their cage so they can wave at more females.  They can also climb out of their cage unless you cover it securely.

She's playing "Queen of the Mountain."  The male fiddler crabs are arguing.

Females in the Wild:  Female fiddler crabs also dig burrows and come out when the tide recedes to look for algae and guys with big claws.

 

Threats in the Wild:  Big wading birds love tasty little fiddler crabs.  Turtles ditto.  Also raccoons and big frogs and toads.  Not too many restaurants tho serve fiddler crabs on their menu.  Indoors, their main threat is climbing out and drying out.

 

 

Water Conditions:  Add a teaspoon of salt per gallon of water. Change your fiddler crab water often.

Fiddler crabs often get shipped with these Styrofoam "peanuts."

In sand, fiddler crabs have no problem digging burrows.

Males in the Wild:  Male fiddler crabs dig deep burrows in the mud.  When the tide approaches (twice a day), they pull a lid over their burrow and retreat into the safety of their little hidey-holes. As the water withdraws, they flip their lids and start looking for algae and fiddler babes.  When they see a female, they start waving that big claw around and making kissy-kissy noises (actually, rattling their big claw against their burrow walls) in hopes of coaxing one of the nubile female crabs into their boudoir to look at their etchings.

Male fiddler crab in back checking out the comely lass in the foreground.

Two eyeballs.  Big claw for the ladies.  Little claw for food.  He has his priorities straight.

Last Word:  If you hear strange sounds coming from your fiddler crab corral at night, relax.  Your fiddler crabs are just fiddling around. 

 

Courtesy to : www.aqualandpetsplus.com 

We're teaching Buster (Buster Crabbe, get it?) to wave goodbye.

♫ "Mr. Sandman, bring me a dream..." ♫

You won't want to run this many head of fiddler crabs on your own crab ranch.

Plants:  Immaterial to the crabs, but planted tanks (even plastic plants) make their biotope look better to us.  Feng shui does not seem to apply to fiddler crabs.

Bits of decor also give your fiddler crabs more room to roam.

Tank Mates:  You can mix them with equal-sized non-violent terrarium residents.  Anoles, fire-belly toads, newts, dwarf African frogs come to mind.  Even tho those big claws look formidable, these guys are not crayfish.  You can pick them up with impunity (or with a net if you are fresh out of impunity).  Cover your net.  Fiddler crabs skitter out of a net in an instamante.

Harmless little mini-critters that clean the beaches.

Substrate Choice:  Dirt, coconut fiber, potting soil, or vermiculite would make a good substrate to burrow into.  Most people use gravel or sand.  Fiddler crabs blend into natural gravels.

 

Mini-Caves.  Since few cages are tall enough to provide two feet of substrate to burrow into, you may want to give your fiddler crab a mini-cave or at least an object to dig under.

White sand makes an excellent fiddler crab substrate.  They show well.

Is this a May Day dance?

Space Requirements:  In small groups your fiddler crabs will want a square foot of space each.  When you crowd them like we do, they seem to lose interest in arguing.  They’ll act more naturally (argue more) in smaller herds.

 

Breeding:  If the male fiddler crab coaxed a female into his burrow for a two-week honeymoon, she will produce numerous eggs (in the thousands) that drift off into the ocean.  Hard to duplicate in the average backyard.

Fiddler crabs actually blend into multi-colored gravels.  Choose a contrasting color.

Foods:  Most important, provide their food in a shallow dish – one they can get in and out of easily.  Hermit crab food works great. Probably anything you give them will work.  Change their food daily.  Once most foods get wet, they start growing moldy and … oh, wait, they eat that too.  But you want a cage that smells clean, so change their food daily.  You for sure want to avoid providing a home for those pesky gnat-like flitterbys that always find smelly food.  Fiddler crabs eat surprisingly daintily.  They pick up each tiny speck of food and carefully place it into their mouths -- unlike the larger crabs that greedily grab the biggest chunks they can find and run off with them.

Change that food daily before it spoils.

Size:   We call them mini-crabs because they top out at about 1.5 inches – plus that great big claw on the male fiddler crabs.

Big claw.  Eyes on stalks.  Mouth in the middle of his chest.  Hairy legs.  Very sexy.

 Fiddler crab anatomy :

 

Fiddler Crabs as Pets :

 

courtesy to Ron Hines DVM Ph.D @  www.2ndchance.info 

 

 

A typical paludarium set up for fiddler crab 

Species : 

 

The following lists all 102 of the currently recognized species of fiddler crab, as well as 5 fossil species (marked with). See the complete name index for alternate species names and spellings.

 

Introduction :

 

As individual pets, hermit crabs have much more personality than fiddler crabs. But if if you want a shared environment including crabs and fish then fiddler crabs are for you. There are over 90 species of fiddler crabs. All belong in the genus, Uca. This crustacean is named for the fiddle-shaped large claw present on males. This entire group is comprised of small crabs – the largest being slightly over two inches across. Fiddler crabs are found along sea beaches and brackish inter-tidal mud flats, lagoons and swamps.

 

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 present when they molt. If the large fiddle claw is lost, males will develop one on the opposite side after their next molt. Newly molted crabs are very vulnerable due to their soft shells. They are reclusive and hide until the new shell hardens.

 

Where To Get Your Fiddler Crab:

 

The fiddler crabs sold in pet stores generally come from brackish water lagoons. Because they live in lower salinity water, pet stores may call them fresh-water crabs. Regardless what your are told, they can not survive indefinitely in fresh water. Try to purchase crabs that have not been stored in fresh water more than a few days. Pick individual crabs that are perky and active and that have all their claws and legs. If you live in a coastal area you may be able to find fiddler crabs in mud and sand inlet beaches and marshy area at low tide.

 

Setting Up The Aquarium:

 

The first thing to do is to buy your aquarium. A ten gallon aquarium will house four medium size 1-2 inch) fiddler crabs with sufficient space to prevent aggression. Prepare a sloping sand area for the crabs to bury themselves. If you add brackish water fish to this habitat you will want a larger aquarium. Fish such as platies, mollies, guppies and swordtails as well as ghost shrimp will adapt to moderate salinity. Set up some type of bubblier aeration system to oxygenate the water. 

 

Water Quality:

 

I prepare a brackish water solution by adding two and one-half teaspoons full of sea or aquarium salt to one gallon of water. If you have a hygrometer, attempt to reach a specific gravity reading of 1.01-1.08. Let the water sit overnight so that chlorine and chloramines dissipate. I change the water every two weeks but you can add at biowheel ammonia and nitrate removal system so you do not have to change the water.

 

Carbonate Hardness (KH) and pH:

 

Fiddler crabs do well with a pH or acidity of 8.0-8.3. Purchase as KH test kit as well. Carbonate Hardness (KH) should optimally be between 150-350 ppm but crabs and some fish will tolerate a much higher levels.

 

Substrate :

 

Fiddle crabs do no do well if they do not have access to dry beach sand or dry to moist rock surfaces. The easiest way to obtain a “beach” is to taper a sandy slope into the water. Triple-washed masonry sand makes a good “beach” for the crabs to get out of the water. Although the crabs seem to do as well using gravel they enjoy digging in the sand more.

 

Temperature:

 

Fiddler crabs do well in a range of temperatures between 75-85 F (24-29 C). If you keep fish in the tank the temperature may need to be regulated more precisely.

 

Diet:

 

Fiddler crabs are normally scavengers feeding on microscopic dead organic mater, plants, algae and animals.. In the wild, they find this food in the sand or mud. Female crabs feed with both claws. The large claw of males is a display apparatus to attract females and is not used for feeding. In aquarium situations feed the crabs sinking crab food, shrimp pellets and freeze dried shrimp and plankton. You can supplement their diet with seaweed purchased from an oriental foods market, sliced zucchini, fresh fish, and aquarium seaweed. Do not foul the water with excessive food.

 

When crabs molt, allow them to eat the shed exoskeletons. This gives them an additional source of calcium.

 

Fiddler Crab Health:

 

Fiddler crabs that are healthy will grow and molt at regular intervals. Missing claws and legs will regenerate over several molts. If the large showy claw is lost to a male it will regenerate over several molts on the opposite side.

 

Male fiddler crabs are territorial. They will fight to protect their turf. To prevent this, do not place too many crabs in the tank. Females are less aggressive.

 

Specific disease among captive fiddler crabs is rare. Most problems result from improper salinity, pH or temperature or too many crabs in a limited area. Crabs also die if they were kept in fresh water at the pet store.

 

Calcium and Iodine

 

Calcium and Iodine are required for molting. Calcium is also required for proper nerve function. The best source of these micro-nutrients is a product such as instant ocean.

  • Uca acuta

  • Uca albimana

  • Uca annulipes

  • Uca antiqua- fossil

  • Uca arcuata

  • Uca argillicola

  • Uca batuenta

  • Uca beebei

  • Uca bellator

  • Uca bengali

  • Uca boninensis

  • Uca borealis

  • Uca brevifrons

  • Uca burgersi

  • Uca capricornis

  • Uca chlorophthalmus

  • Uca coarctata

  • Uca coloradensis

  • Uca crassipes

  • Uca crenulata

  • Uca cryptica

  • Uca cumulanta

  • Uca dampieri

  • Uca deichmanni

  • Uca demani

  • Uca dorotheae

  • Uca dussumieri

  • Uca ecuadoriensis

  • Uca elegans

  • Uca excisa

  • Uca festae

  • Uca flammula

  • Uca forcipata

  • Uca formosensis

  • Uca galapagensis

  • Uca hamlini -fossil

 

  • Uca helleri

  • Uca herradurensis

  • Uca hesperiae

  • Uca heteropleura

  • Uca hirsutimanus

  • Uca inaequalis

  • Uca insignis

  • Uca intermedia

  • Uca inversa

  • Uca iranica

  • Uca jocelynae

  • Uca lactea

  • Uca latimanus

  • Uca leptodactyla

  • Uca limicola

  • Uca longidigitum

  • Uca longisignalis

  • Uca major

  • Uca maracoani

  • Uca marguerita

  • Uca marinae - fossil

  • Uca minax

  • Uca miocenica-fossil

  • Uca mjoebergi

  • Uca monilifera

  • Uca mordax

  • Uca musica

  • Uca oerstedi

  • Uca oldroydi-fossil

  • Uca ornata

  • Uca osa

  • Uca panacea

  • Uca panamensis

  • Uca paradussumieri

  • Uca perplexa

 

 

  • Uca polita

  • Uca princeps

  • Uca pugilator

  • Uca pugnax

  • Uca pygmaea

  • Uca rapax

  • Uca rhizophorae

  • Uca rosea

  • Uca saltitanta

  • Uca seismella

  • Uca signata

  • Uca sindensis

  • Uca speciosa

  • Uca spinicarpa

  • Uca splendida

  • Uca stenodactylus

  • Uca stylifera

  • Uca subcylindrica

  • Uca tallanica

  • Uca tangeri

  • Uca tenuipedis

  • Uca terpsichores

  • Uca tetragonon

  • Uca thayeri

  • Uca tomentosa

  • Uca triangularis

  • Uca typhoni

  • Uca umbratila

  • Uca uruguayensis

  • Uca urvillei

  • Uca victoriana

  • Uca virens

  • Uca vocans

  • Uca vocator

  • Uca vomeris

  • Uca zacae

 

2- Rainbow Land Crab
Cardisoma armatum

 

Rainbow Land Crabs are found along river and costal areas of west Africa. With a blue to purple carapace and bright orange to red legs, they make an attractive pet.

 

What does a Rainbow Land Crab look like?

 

The Rainbow Land Crab is a brightly colour crab. They have a blue to purple carapace and orange to red legs. The males are more colourful compared to females. It has been known for specimens to reach sizes of 15-20cm (6-8 inch) across the carapace, average size is smaller at around 10cm (4 inch). Their average lifespan is two to three years.

 

Where are Rainbow Land Crabs from?

 

Rainbow Land Crabs can be found living within burrows along river and/or costal areas of west Africa, they are mainly imported from Nigeria.

 

How do you keep Rainbow Land Crabs?

 

You will require a glass or plastic tank (latter being cheaper) with a floor space of at least 30cm for one Rainbow Land Crab. You can keep this species together but is advised to house in larger enclosures with plenty of hides.

 

n their natural environment, they would make burrows in the mud along the waters edge. You can use the Exo Terra Riverbed Sand or a sand/soil mixture. Place at least 2 inch, ideally 3-4 inches of the substrate in your enclosure with stones, cork bark and other items as hides.

 

Not much information can be found on the temperatures that Rainbow Land Crabs should be kept at. We keep ours in a warm reptile room, temperatures range between 20-24C. We have heard that UV lighting is not essential, but this does bring out their colours and may help when shedding their exoskeleton.

 

You can provide Rainbow Land Crabs with either fresh or brackish water. If using water from your tap, you must allow this to stand for at least 24hrs or treat with a de-chlorinator before placing in with your pet crab/s. Depending on the size and type of set you have, the use of a water dish makes changing and maintaining the water easier, where as a 50/50 land and water makes the enclosure look more natural.

 

Feeding Rainbow Land Crabs shouldn't be a problem, they are scavengers and will eat pretty much anything you offer. Give them a varied diet of fruit, vegetables, bloodworm, fish, pinkies, turtle or crab pellets. Also provide some cuttlefish as we believe they may require this for their exoskeleton.

Origin :

West Africa

Maximum Size :

Three-inches plus legs

Life Span :

Probably five years

Life Style :

Scavenger. Likes to hide. Pugnacious.

Temperature : 

Flexible -- 75 to 85 works fine

Threats :

Other crabs. Copper.  Long legged shore birds like herons.

Substrate :

Not too important

Foods :

Dead fish and any commercial pet food

Supplements :

Maybe a cuttlebone

Containers :

Needs a 10-gallon minimum

 

Pretty good-looking patriot crab, even if he is left-handed.

 

Origin:  Last millennium, we never really knew where patriot crabs came from until one of our Nigerian customers saw them and said they were very common in Nigeria. 

 

Soap dish crab shipping containers full of cargo.

 

Soap Dish Crabs:  Patriot crabs were originally shipped in plastic soap dish containers and were thus called "soap dish crabs."  They came in yellow, purple, red, and blue.  They have a long list of AKAs, so you'll find them under a variety of names, like rainbow crabs, moon crabs, Columbian crabs, and others.

One submerged.  One emersed.

 

Life Style:  Adult patriot crabs like to mix it up.  However, most are just as happy to hide.  In the wild they would dig burrows.  In captivity they're just as likely to scoot under a rock or piece of driftwood.  They live at the edge of the water.  They survive under water for long periods but need access to land to catch their breath.  Like all crabs, they have gills that must be kept moist, so they need access to water at all times.  A tank with half water and half land works well.  Or you can give them an easy to enter and exit dish of water and mostly land.  There's no magic formula.

 

Right-handed crab and left-handed crab. 

 

Water:  Do they do best on freshwater or brackish water?  Yes.  They do just fine on both.

 

Typical crab hang out.  A little on the tacky side.  You can see two of the four in here.

 

They're all out of sight here.

 

Patriot crabs do fine in bare tanks.

 

And they show up well over white gravel.

 

Substrate:  Bare tank, sand, gravel (natural or colored) make little diff to your crab.  However, they seem to blend into natural and multi-colored gravels. 

 

Live Plants?  Patriot crabs are scavengers.  They eat whatever they find -- including live plants.

 

Temperature?  Patriot crabs do well at 75 to 85 F.  In the wild, they probably face much more variation in their ambient temp.  Your best bet is to call a friend in Lagos and ask for their temp each day.  Suffice it to say, they probably cool off a great deal at night.

 

 

 

Male patriot crab in combat mode.

 

Four confused patriot crabs not knowing who to argue with first.

 

Threats.  Patriot crabs are not schoolers like many of the mini-crabs.  They fight.  Give them plenty of room.  Copper is also a killer of all invertebrates.  Avoid medications.  And keep all long-legged shore birds out of their habitat.

 

Older crabs lose some of their bright colors.  He also lost one of his legs.  Incredibly careless. 

 

Oops.  Here it is.  He'll grow it back on his next molt.

 

Dis-Armaments.  When patriot crabs argue, they try to tear off each other's arms and legs.  If they lose any parts, they are at a disadvantage when eating and when fighting.  Separate any walking (or non-walking) wounded.  They will grow new parts at their next molt.  It may take half a year for them to get back into fighting trim.

 

Newly emerged crab and his "old suit."

 

Another squishy "soft shell" crab.

 

Shell Shedding.  Crustaceans grow by taking in water, flexing their muscles,  and splitting their shells.  They then wriggle out of their former old shells and scuttle under a rock until their new shells harden.  At this stage, they are softer, helpless, and tastier.  Their fellow crabs have few compunctions against cannibalism at this time.  They will usually eat their old shell so the calcium does not go to waste.

 

Here's his old "house."

 

Belly of a male patriot crab. 

 

Ditto female patriot crab.

 

Sexing.  Look at their tail flap.  It's narrow on the males and wider on the females.  Pretty much like all crabs.  Don't worry, you won't breed them anyway.

 

They scuttle right out of a net.

 

Capturing Crabs.  You can learn a great deal by picking up a patriot crab -- especially if you try it bare handed.  If you use a net, they scuttle out of that pretty fast.  A plastic drinking glass (don't worry about plastic glass being an oxymoron) probably works best.

 

Mixing with Fish?  We've already mentioned that 100% water works not so well.  That doesn't mean no one does it.  If you hold a patriot crab in your hand, you will see why fish do not do well in the same habitat.

 

His mouth is at the top of his chest.

 

How Do They Eat?  You'll notice patriot crabs stuffing food into the top of their chest.  If you saw the movie Predator, you have a good idea of how their mouth works.

 

 

 

They quickly learn to eat from your fingers.  Watch yours.

 

Last Words.  Patriot crabs do like dead goldfish or whatever else they find.  They'll do just fine on any of the pelleted pet foods for birds, lizards, ferrets, cats, dogs or whatever.  If you like to add supplements, add a piece of cuttlebone.  Patriot crabs are as easy to keep as a crawdad. 

 

Cardisoma armatum paludarium :

 

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