African Freshwater Crab Potamonautes niloticus

Potamonautes niloticus is a large and robust African freshwater crab distributed across the Nile Basin and East African river systems. It inhabits a wide range of freshwater habitats including rivers, streams, swamps, and lake margins, displaying considerable ecological flexibility. Its carapace is broad, smooth, and ranges from olive-green to reddish-brown, with powerful chelae capable of significant force.

In captivity, P. niloticus is kept as a fully aquatic species, unlike many crabs that require land areas. However, a slightly raised edge or emersed area where the crab can rest at or near the water surface is beneficial and reduces stress. The tank should be spacious with numerous rocky caves and overhanging structures to allow the crab to establish a territory without constant confrontation.

This species is an opportunistic omnivore in the wild, consuming invertebrates, plant material, carrion, and organic detritus. In captivity it accepts most sinking foods readily. It is territorial and should generally be kept one per tank unless the enclosure is exceptionally large. A secure, weighted lid is important as large potamid crabs are surprisingly capable climbers.

Water: 20–26°C, pH 7.0–8.0, GH 6–18, KH 3–12; high filtration; partial water changes weekly. Tank: minimum 100 L; rocky caves mandatory, fine gravel or sand substrate, robust filtration; secure weighted lid. Feeding: omnivore — sinking pellets, frozen bloodworm, mussel, blanched vegetables, dried shrimp; feed every 1–2 days. Breeding: females brood eggs; juveniles fully aquatic; large space required for breeding pairs. Compatibility: one per tank unless very large; will eat shrimp, snails, and small fish; keep with robust larger fish only.