Guinea-Bissau: Orango Island – African Fiddler Crabs
Orango Island in the Bijagos was swarming with small crabs – African Fiddler Crabs aka Afruca tangeri in Latin. The island is fringed with mangrove tidal flats that see massive tide swings and thus millions of crabs running around! These species are found along the Atlantic coast of Africa, especially in the West Africa. They are prevalent in mangrove forests and estuarine mudflats, including the Bijagós Archipelago. Males and females can be easily distinguished by their claws. Males have one enlarged claw, which can be either the left or right, used for communication and combat, while females have two smaller claws of equal size. If a male loses his large claw, he can regenerate it. The smaller claw will grow larger, and the lost large claw will regenerate as a small claw. During the breeding season, males use their large claw to attract females by waving it in a distinctive manner. Females select mates based on the size and vigor of the claw-waving display.. They build burrows in the mud, that can be quite complex, with multiple chambers and entrances. These crabs are detritivores, feeding primarily on organic material found in the sediment. They sift through the mud, extracting microorganisms and organic particles. Their activity is closely tied to the tidal cycle. They forage during low tide when the mudflats are exposed and retreat to their burrows during high tide.
