The Tiny Mangrove Tree Crab

April 3, 2023

Species Highlight: Mangrove Tree Crab | Written by Science Intern, Julia Galante

Mangrove forests host a wide range of biodiversity, many of which are invertebrates. Most invertebrate species utilize the mangrove root systems as shelter and protection from predators. Some invertebrate species that can be found in mangrove forests include snails, barnacles, mollusks and isopods. 

However, there is one species that specializes in living in the tree canopy – mangrove tree crabs.  

Mangrove tree crabs (Aratus pisonii) are a small species of crab that can be found throughout the mangrove forests of Florida. These crabs have a very wide range, which can extend to areas of Central and South America. The mangrove tree crab spends most of its time in red mangrove trees, but can also be found in the surrounding white and black mangroves. 

Mangrove tree crab found on the Gordon River Greenway

As the name suggests, mangrove tree crabs are adapted to living in the trees. Their coloration helps them blend into their surroundings, specifically tree bark. These crabs have small, black hairs at the tips of their legs that help them climb the trees and cling to foliage. Tree crabs are considered to be omnivores; however, most of their diet consists of mangrove leaves. During periods of low tide, mangrove tree crabs will descend the trees to forage in the exposed mud where they will feed on decaying mangrove roots, algae, and smaller invertebrate species. Several species will prey on the crabs, such as birds and raccoons.


Mangrove tree crabs play a vital role in mangrove ecosystems by eating organic debris and recycling nutrients, which helps improve the growth of mangrove trees. The current status of the mangrove tree crab is undetermined. However, mangrove ecosystems as a whole are threatened due to natural stressors and anthropogenic development. 

As we continue to learn more about the mangrove forests, it is important to remember the charismatic macroinvertebrate that contribute to the health of these ecosystems, such as the mangrove tree crab.

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