Dromiidae
Dromiidae, commonly known as “sponge crabs” or “box crabs”, are a family of crabs that are found in marine environments worldwide. They are characterized by their unique ability to carry sponges and other sessile organisms on their backs for camouflage and protection. This behavior, known as “carrying”, is a defining feature of the family and is often used to distinguish them from other crab families.
Characteristics
Dromiidae crabs typically have a broad, flattened carapace (shell) and are often brightly colored. Their legs are short and stout, and their claws are relatively small. They are also notable for having a pair of specialized appendages called "dactyls" on the third pair of legs. These dactyls are used to hold the sponges and other materials that the crabs carry on their backs.
The carrying behavior of dromiidae crabs is believed to serve several purposes. First, it provides camouflage, making the crabs difficult for predators to see. Second, it offers protection from predators, as the sponges and other materials can be used to deter or ward off attackers. Third, it may provide a source of food, as the sponges and other materials can be eaten by the crabs.
Environment
Dromiidae crabs are found in a variety of marine environments, including shallow reefs, seagrass beds, and rocky shores. They are typically found in tropical and subtropical waters, but some species are also found in temperate regions.
Distribution
Dromiidae crabs are found in all major oceans around the world. Their distribution is widespread, ranging from the tropical waters of the Indo-Pacific region to the colder waters of the Atlantic and Pacific Oceans.
Diet
Dromiidae crabs are omnivores, feeding on a variety of organisms, including algae, sponges, and small invertebrates. They are also known to scavenge on dead animals.
Reproduction
Dromiidae crabs reproduce sexually, with females laying eggs that are attached to their abdominal appendages. The eggs hatch into larvae that drift in the water column before settling to the bottom and developing into juvenile crabs.
Classification
The family Dromiidae is classified within the order Decapoda, which includes all crabs, lobsters, and shrimp. The family is further divided into several subfamilies and genera, containing over 100 species worldwide.
Notable Species
Some notable species within the family Dromiidae include:
- Dromia personata (the "masked crab")
- Dromia erythropus (the "red-legged crab")
- Dynomene hispida (the "hairy crab")