The Red Jamaican Crab (Gecarcinus ruricola), is found in the Caribbean Sea and parts of Central and South America. This large, colorful crab is is known for its bold appearance and ecological role.
This real-life inspiration behind Sebastian, the beloved musical crab from Disney’s The Little Mermaid boasts a vibrant red coloration and large, expressive claws. Its lively movements and ecological role as a scavenger further enhance its captivating presence in the coral reef ecosystem.
Read on to explore facts about this well-known species of crab.
Appearance
The dark coloration of Red Jamaican Crab, typically ranges from deep purple to black and provides camouflage in their terrestrial habitats. They have a broad, flattened carapace (shell) and long, sturdy legs. Their claws are robust and used for food handling, defense, and digging burrows for shelter or accessing water.
These crabs are nocturnal, they spend most of their lives moving around when it’s dark outside. This prevents the crabs from drying up in the hot sun. The crabs grow around 1 inch per year when they’re young. They reach maturity around five years of age and can live for another five.
They have evolved primitive lung-like structures that allow them to extract oxygen directly from the air. They can store water in their branchial chambers, which helps keep their respiratory surfaces moist for efficient gas exchange. Waste filtration happens through specialized organs like green glands.
The Red Jamaican Crab has mechanisms to minimize water loss, such as a thick cuticle (outer layer), and behavioral adaptations like seeking humid environments or burrowing. They can also regulate the salt balance in their bodies to cope with the lack of a constant saltwater environment.
Did you know…
Red Jamaican crabs are known for their impressive burrowing abilities, which they use to create complex underground networks of tunnels and chambers. These burrows serve as shelter from predators and extreme weather conditions, as well as a place to store food and water.
Habitat
The Red Jamaican Crab is found throughout the Caribbean and as far east as Barbados. It prefers warmer waters and has been spotted in Florida and even Nicaragua, but these reports are few and far between. There are populations off the Colombian coast as well as in the Swan Islands around Honduras.
They spend most of their day hiding in burrows or under rocks to avoid predators and the hot sun. At night, they emerge from their hiding spots to forage for food and engage in social interactions with other crabs.
Interestingly, the Red Jamaican crab has been spotted at an altitude of 980 feet, or 300 meters, on land. In Jamaica, it was found at 3,300 feet or 1,000 meters.
Diet
These red crabs search for food along the ocean floor, eating anything with some substance. This includes parts of other crabs, squid, fish, and starfish. They also enjoy eating whole smaller organisms like worms. They live primarily on land but still visit the sea occasionally.
Reproduction
The breeding season typically occurs between May and August, Male crabs engage in aggressive behaviors to compete for female attention. This can include fighting, claw-waving, and vocalizations.
When the red Jamaican crab lays its young, it does so in the sea. The larvae live as plankton as they grow. They’re quite small at first, sometimes returning to land. This creates a phenomenon known to turn roads red.
The first three years of the crab’s life are spent living in burrows created and inhabited by other crabs. They also eat the food supplied to them by these older crabs.
One female may carry around 85,000 eggs at one time. These are released during mass migrations.
Threats
The red Jamaican crab is at threat from the same sources as most ocean-dwelling species. This includes changes in ocean currents, temperature, and the level of the water itself. Coastal erosion is also an issue that these creatures contend with, as is human encroachment on their coastal habitats.
Common predators include fish and eels (especially when the crabs are young), as well as larger types of fish, some sharks, and other large ocean species.
Interestingly, two different organisms commonly use the red Jamaican sea crab as a host. These are commensal flies of the genus Drosophila. The first is Drosophila carcinophila, and the second is Drosophila endobranchia. The flies spend most of their lives on the crabs. This allows them safety from most predators due to the speed of the crabs and their willingness to flee at a moment’s notice.
The flies lay eggs around the Red Jamaican crab’s eyes that then migrate to the crab’s nephritic pad. There, they live and feed on microbes. They move to the crab’s gill chamber and into the mouthparts throughout their lives as well.
More Interesting Facts about Red Jamaican Crab
- The first three years of the crab’s life are spent living in other crabs’ burrows.
- The crab is also sometimes referred to as the zombie crab.
- They exist in four distinct colors: black, red, yellow, and green.
- These crabs are darker on their upper side than their underside.
- Other members of the family include the Black Land Crab (Gecarcinus lateralis), the Purple Land Crab (Gecarcinus purpureus), and the Bermuda Land Crab (Gecarcinus laevimanus).
FAQs
Does it bite?
If threatened or mishandled, they may attempt to pinch or bite. While their bites can be painful, they typically do not cause severe injury or break the skin.
Are Jamaican red crabs consumed by humans?
Yes, Gecarcinus ruricola, the black land crab, is consumed in some regions, particularly in the Caribbean. Its meat is considered edible and is used in various dishes, including soups, stews, and other traditional preparations. In some Caribbean cultures, land crabs hold cultural importance and are part of the local cuisine.
Can these crabs be kept as pets?
As terrestrial crabs, they have evolved to live on land and require a specialized habitat that mimics their natural environment. A terrarium or paludarium setup is necessary to keep them as pets. A terrarium provides a land area with substrate, hiding places, and controlled humidity. However a paludarium combines land and water elements, allowing the crab access to both environments, which can be beneficial for their foraging and behavioral needs.
What is the ecological role of Red Jamaican crab in the environment?
Red Jamaican Crab plays a multifaceted ecological role as a scavenger, omnivore, and prey within its environment. By consuming carrion and plant matter, it facilitates nutrient cycling and decomposition. Seed dispersal through its digestive process contributes to forest regeneration. As a food source for various predators, it supports the food web. Its burrowing behavior enhances soil aeration and structure.
(featured image credit: P.Lindgren)
