Calappidae
Calappidae is a family of crabs commonly known as box crabs or horseshoe crabs. These crustaceans are characterized by their flattened, box-like carapace, which is often adorned with prominent spines or ridges. They are found in a variety of marine environments, ranging from shallow intertidal zones to deep waters.
Characteristics
Calappidae crabs exhibit several distinguishing characteristics that set them apart from other crab families. Their most notable feature is their broad, flattened carapace, which provides a protective shell for their soft underbelly. This carapace can be significantly wider than it is long, giving it a distinctive box-like appearance.
The carapace is typically adorned with spines or ridges, varying in number and prominence depending on the species. These projections serve as a form of defense mechanism, deterring predators and providing camouflage. They also have a pair of prominent, movable eyestalks that allow them to scan their surroundings for potential prey or threats.
Calappidae crabs are typically stout and have relatively short legs, designed for walking and digging. Their claws are often powerful and equipped with sharp edges, used for catching prey and defending themselves. The abdomen is tucked beneath the carapace, offering protection and allowing for a compact body structure.
Environment
Calappidae crabs can be found in various marine environments, demonstrating a remarkable degree of adaptability. They inhabit intertidal zones, coral reefs, seagrass meadows, sandy bottoms, and even deep-water environments.
Many species are known to burrow into the substrate, creating shelters that offer protection from predators and environmental stressors. The location of these burrows can vary depending on the species, with some preferring rocky crevices while others favor sandy beaches.
Diet
Calappidae crabs are primarily scavengers, feeding on dead animals and decaying plant matter. They are also known to be opportunistic predators, consuming small invertebrates such as worms, mollusks, and crustaceans. Their powerful claws are well-suited for crushing hard-shelled prey.
Reproduction
The reproductive cycle of Calappidae crabs involves external fertilization. Females release eggs into the water, where they are fertilized by males. The eggs develop into larvae, which undergo several molts before reaching their adult form. The larvae are typically planktonic, drifting in the currents until they settle on the seabed and transform into juveniles.
Conservation
While some species of Calappidae crabs are considered abundant, others are facing threats due to habitat loss, overfishing, and pollution. Conservation efforts are essential to protect these unique and important members of the marine ecosystem.
References
World Register of Marine Species
Diversity and Distribution of Decapod Crustaceans in the Southeastern Brazilian Continental Shelf