Mangrove Root Crab

Here are key identification features of Goniopsis cruentata:

Carapaces are quadrangular, somewhat flat on the front, with large white spots at the edges, and short eye stalks which are reddish. Carapaces are up to 6.59 cm (2+5⁄8 in) in diameter. Males have larger carapaces than females, though female carapaces have wider rear ends.

Legs are reddish with dark spots, and bearing conspicuous bristles.

Claws, or chelae, are red except for the palms, which are almost white, and the fingers, which are yellow.

Juvenile Goniopsis cruentata easily can be confused with other species.

In the Americas, Goniopsis cruentata occurs along the coasts as far north as southern Florida in the USA, and the state of São Paulo in Brazil, in between including the Caribbean and Gulf of Mexico. Along the African coast it occurs from Senegal to northern Angola.

In northeastern Brazil, Goniopsis cruentata usually is not sold as whole individuals but rather as processed meat, popularly known as catado. Between 120-150 adult crabs are needed to produce 1 kg (2+1⁄4 lb) of catado, so harvesting the crab for commercial purposes heavily impacts natural populations.

Crabs in the family Grapsidae, such as Goniopsis cruentata, by consuming such large quantities of mangrove leaf litter, often serve as primary consumers. Thus, in the context of the Carbon Cycle of the mangrove ecosystem, they may be the main processors of mangrove carbon. This breaking down of leaves into tiny particles by digestion encourages microbial colonization and further biodegradation of organic matter, in support of the mangrove ecosystem's nutrient cycle.

Also Goniopsis cruentata plays an important role in propagule predation, and may affect Mangrove recruitment and community composition. Habitat destruction along with long-term overfishing of the species can have irreversible consequences affecting the entire mangrove ecosystem. Goniopsis cruentata are predators known to hunt fiddler crabs and Mangrove Tree Crabs