Mangrove Crab Chiromantes ortmanni

Chiromantes ortmanni is a small sesarmid crab found across Indo-Pacific mangrove habitats from East Africa through South Asia to the western Pacific. It inhabits the upper intertidal zones of mangrove forests, where it spends most of its time on emergent mud, root surfaces, and leaf litter, retreating to burrows or water when disturbed.

Like most mangrove sesarmids, C. ortmanni is semi-terrestrial and thrives best in a paludarium that replicates a tidal mangrove shoreline: a brackish water section, a muddy substrate slope, and an above-water area with mangrove root structures and leaf litter. Its carapace is dark — ranging from deep brown to near-black — and adults are compact, reaching about 2.5 cm carapace width.

In captivity this species adapts to a broadly omnivorous diet including dried leaves, sinking pellets, dried invertebrates, and blanched plant material. It is active and will forage both day and night. Groups of mixed sexes can be maintained in a suitably structured enclosure. Larvae require full marine conditions, so captive breeding through metamorphosis is impractical for most hobbyists.

Water: 20–28°C, pH 7.5–8.5, GH 10–22, KH 4–14; brackish 1.003–1.010 SG; muddy shoreline substrate. Tank: minimum 50 L paludarium; muddy intertidal zone, mangrove roots, leaf litter, above-water area; secure lid. Feeding: omnivore — dried leaves, sinking pellets, dried shrimp, blanched vegetables, algae; feed every 1–2 days. Breeding: larvae require full marine conditions; captive breeding through larval stages not practical. Compatibility: groups in spacious tanks; semi-terrestrial; incompatible with shrimp; do not mix with large fish.