Red Sea Land Hermit Crab

The 🌊 Red Sea Land Hermit Crab, scientifically known as Coenobita scaevola, is a species of terrestrial hermit crab found along parts of the 🌊 Indian Ocean, including the 🌊 Gulf of Aden and the coasts of 🇸🇴 Somalia and 🇵🇰 Pakistan. This species is the only terrestrial hermit crab in the 🌊 Red Sea region. The crab was first described by Peter Forsskål in 1775, with the type locality being Jeddah, 🇸🇦 Saudi Arabia.

The typical size for Coenobita scaevola is around 5 cm (2 in). This species is adapted to arid environments, such as those found on the Sinai Peninsula, but it needs to stay near the shore. The crab must return to the sea periodically to replenish the water stored in its shell, which is essential for respiration. During the day, the crab shelters in burrows or among coastal vegetation to escape the heat, only emerging at night to feed. Although daytime temperatures above ground can reach 33 °C (91 °F), just 10 cm (3.9 in) below the surface, temperatures remain cooler, not exceeding 28 °C (82 °F).

Reproduction occurs in the hottest months when the temperature ranges from 24 to 38 °C (75 to 100 °F). Like other hermit crabs, the young of Coenobita scaevola pass through several larval stages, totaling a lengthy 54 to 80 days. This species has the highest number of such phases among hermit crabs, with seven zoeal stages.

Coenobita scaevola typically occupies shells for protection and moisture retention. Most adults, with a carapace length of up to 7.5 mm (0.30 in), are found in Nerita undata shells. Larger crabs prefer shells from Turbo radiatus, Polinices milanstomus, and Monodonta canalifera, while the smaller ones (below 3 mm or 0.12 in) select shells from Planaxis sulcatus and Nassarius arcularia.