African Freshwater Crab Potamonautes perlatus

Potamonautes perlatus is a fully aquatic freshwater crab endemic to the Western Cape of South Africa, inhabiting the cool, clear mountain streams and rivers of the Cape Fold Belt. It is adapted to the fynbos biome's water chemistry — typically soft, slightly acidic to neutral, well-oxygenated water originating from high-altitude quartzite catchments. Adults display a smooth, moderately broad carapace in olive-brown to warm tan colouration.

As a cool-water species, P. perlatus requires considerably lower temperatures than most freshwater crabs in the hobby — 14 to 22°C covers its natural seasonal range. Attempting to maintain it at tropical temperatures will result in stress and shortened lifespan. Excellent filtration and water quality are important, as mountain streams have very low organic loading naturally.

This species is territorial and should be kept individually or in very large tanks with clearly separated territories. It is an opportunistic omnivore consuming invertebrates, plant material, and organic detritus. A direct developer, females brood large-yolked eggs and release fully formed juveniles. P. perlatus holds ecological significance in Cape stream ecosystems and should be acquired from responsible captive sources.

Water: 14–22°C, pH 6.5–7.5, GH 3–12, KH 1–8; cool, soft, highly oxygenated; do not heat above 22°C. Tank: minimum 60 L; rocky caves and crevices, fine gravel, strong flow; unheated in temperate rooms; secure weighted lid. Feeding: omnivore — sinking pellets, frozen bloodworm, blanched vegetables, dried shrimp; feed every 1–2 days. Breeding: direct developer; female broods large-yolked eggs; miniature fully aquatic juveniles on release. Compatibility: one per tank; predatory on invertebrates; keep with robust cool-water fish only.