A Complete Guide to Keeping Driftwood Crabs as Pets

An Introduction to Driftwood Crabs

Driftwood crabs, also sometimes referred to as fiddler crabs, are a unique and fascinating type of crab found in coastal and estuarine habitats around the world. They get their name from their frequent association with driftwood, which they rely on as both a food source and habitat.

Appearance and Identifying Traits

One of the most distinguishing features of male driftwood crabs is their one unusually large claw, which can appear up to twice the size of the other. This has earned them the name "fiddler crab" due to the resemblance to a musical fiddler. The large claw is used during mating rituals to attract females and to defend territory.

Driftwood crabs have bodies that measure around 2 inches across as adults. Their carapace is generally a brown or grey color, providing useful camouflage against driftwood. They have nine small legs for mobility, two main eyes on movable stalks, and two more primitive light-sensing eyes towards the front of their bodies.

Habits and Behavior

Driftwood crabs live in large colonies made up of burrows dug into sand or mud of sheltered beaches. They are very social animals and you can often observe complex interactions as they communicate through claw waving, posturing, and by producing vibrations on the ground. Male crabs in particular are quite territorial.

When not socializing or foraging, driftwood crabs spend a lot of time trying to find and decorate the entrance to their burrows. They use items like shells, pebbles, seaweed, and driftwood bits to conspicuously decorate their homes, likely as a way to attract mates.

Unique Relationship with Driftwood

As their name suggests, driftwood plays an especially important role in the lives of these pequeculiar crabs. Their frequent association stems from two related factors:

1. Driftwood provides vital shelter and shady hiding spots from predators in the exposed upper intertidal zone which they favor.
2. They rely on wood that has been weathered by ocean waves as a main food source, using their claws and mouthparts to scrape and nibble on it for the nutritious fungi, algae, and microbes that grow on it.

Driftwood crab colonies are most abundant in areas where driftwood is common, such as near estuaries, mangroves, and areas where prevailing winds and currents accumulate woody debris.

Threats and Conservation Status

Pollution from agricultural and industrial runoff can be a threat to driftwood crab populations living downstream. Oil spills are also hazardous due to their sensitivity to petroleum products. These crabs have high site fidelity and do not easily relocate once established.

Luckily, driftwood crabs remain widespread and abundant globally. Their high fecundity and reproductive rate allows populations to recover quickly compared to other crab species. For these reasons, the IUCN Red List categorizes them as Least Concern.

Keeping Driftwood Crabs as Pets

The small size, hardiness, and fascinating behavior of driftwood crabs makes them popular exotic pets. Here is some key care information if you’re considering getting one:

Housing and Habitat Requirements

A basic driftwood crab setup requires the following components:

• A secure glass aquarium or plastic bin, minimum 10 gallons
• 3-5 inches of proper substrate like washed play sand
• Saltwater mixed to proper salinity between 1.010-1.025 S.G.
• Filtered water circulation via powerhead or tiny sponge filter
• Driftwood, shells, rocks for habitat enrichment
• Shallow plastic lid to retain humidity while allowing oxygen flow

Feeding and Diet

In captivity, driftwood alone is not enough to provide a complete diet. Supplement wood with a quality omnivore pellet or flake food, along with occasional treats like blanched veggies, shrimp, fish scraps, and calcium-rich snail shells.

Handling and Temperament

Despite their small size, driftwood crabs can give a decent nip with their pinchy claws. Scoop them gently with a small net when necessary. They do become very interactive with regular gentle handling though.

These crabs cohabitate well with small docile tank mates like snails. Avoid housing with aggressive fish that may nip vulnerable eyes on their eyestalks which can regrow over several molts.

With the proper setup, driftwood crabs can live 2-3 years in captivity. Their low demands, resilience, and captivating behavior continue to make them uniquely popular pets for crustacean enthusiasts.

FAQs

How big do driftwood crabs get?

Adult driftwood crabs generally reach about 2 inches across in body size. Males develop one claw that grows disproportionately large, up to twice the size of their other claw.

What water conditions do driftwood crabs need?

Driftwood crabs require brackish water with proper salt content, known as salinity. Maintain home aquariums between 1.010-1.025 specific gravity and stable parameters like pH 8.1-8.4, ammonia 0 ppm, nitrites 0 ppm.

How do I pick up a driftwood crab safely?

Use a small aquarium net to gently scoop up driftwood crabs. Avoid grasping crabs with your hands directly as their pincers can deliver a decent nip. Handle them slowly and deliberately to prevent stressful rapid movements.

What do I feed a pet driftwood crab?

In addition to weathered driftwood, feed them a balanced diet consisting of high-quality omnivore pellets or flakes along with occasional treats like blanched vegetables, shrimp, fish scraps, and calcium-rich snail shells.

Can driftwood crabs live together with fish or other animals?

Peaceful community options include other small crustaceans like snails or shrimp. Avoid housing them with aggressive fish that may nip at their vulnerable stalked eyes. Proper habitats allow for visual barriers and hiding spots to help manage aggression.