Vampire Crab Color Morph Comparison Guide: Purple Red Carnival

Few inhabitants of the nano paludarium hobby pack as much visual punch into 2 cm of body as the vampire crab. The deep purple carapace, glowing yellow eyes and contrasting claw colours have made Geosesarma species one of the fastest-growing crab keeping niches in Singapore. Sorting through the vampire crab color morphs at the local importer can be confusing because trade names cross over and several distinct species share the “vampire” label. This guide from Gensou Aquascaping at 5 Everton Park breaks down the four most-traded morphs and how to pick the right one for your build.

Why “Vampire” Stuck

The common name comes from the bright yellow eyes that glow against the dark purple shell, plus the strict crepuscular activity — vampire crabs hide all day and emerge at dawn and dusk to forage. The genus Geosesarma contains over 70 described species, only a handful of which appear in the trade. All require a brackish micro-environment, 50/50 land and water, and a nano paludarium of 30-60 litres.

Geosesarma Dennerle: The Carnival

Geosesarma dennerle is the showpiece of the genus, named for the German aquarium brand that helped popularise it. Carapace is deep violet-purple, claws bright orange to red, and the eyes glowing yellow. Adults reach 2-2.5 cm carapace width. SGD 35-65 per specimen at Singapore importers depending on size and grade. Pair them in a heavily planted nano paludarium with multiple cork bark hides and a shallow brackish pool.

Geosesarma Notophorum: The Purple-Claw

The original “vampire crab” of the trade, G. notophorum, has a uniformly dark purple carapace and matching purple claws — less contrast than Dennerle but a cleaner, more architectural look. Slightly smaller at 1.8-2.2 cm. Females carry eggs and tiny crabs on their backs (the species name notophorum means “back-bearing”), making them one of the few Geosesarma that practices direct development without a larval phase. SGD 25-45 per specimen.

Geosesarma Krathing: The Red-Claw

Named after Khao Krathing in Thailand, G. krathing shows a darker brownish-purple body with vivid red claws — the strongest red expression of any Geosesarma in the trade. Slightly more aggressive than Dennerle, so keep singles or confirmed pairs rather than groups in tight quarters. SGD 40-70 per specimen. Pairs with cork bark and Spanish moss work well in a Southeast Asian biotope build using elements from the decoration and substrate range.

Geosesarma Hagen: The Pink-Red Variant

G. hagen sits between krathing and dennerle in colour expression, with a reddish-purple carapace and pink-red claws. Adults are slightly larger at 2.5-3 cm and tolerate group housing better than the others. The most beginner-friendly species in the genus because of its calm temperament. SGD 30-55 per specimen, usually available at Singapore specialty importers and Carousell vampire crab dealers.

Shared Husbandry Across Morphs

All four species share the same setup requirements: 50 per cent land surface (cork bark, mopani driftwood, terrestrial moss), 50 per cent shallow brackish water at SG 1.005, ambient 24-28°C, humidity 70-90 per cent, and multiple climbing hides. Substrate is a coco fibre and sphagnum moss mix on the land portion, fine sand in the water section. Lighting is moderate — they avoid bright light. Browse the paludarium tank range for nano-sized enclosures suited to vampire crabs.

Diet and Behaviour

Omnivorous scavengers in the wild, vampire crabs accept sinking shrimp pellets, blanched leafy greens, fruit chunks (apple, mango), live or frozen bloodworm and the occasional protein boost from feeder snails. Feed three times weekly in a small dish on the land portion to keep waste contained. They moult every six to eight weeks and need calcium-rich water; cuttlebone fragments and a small amount of crushed coral in the water section help.

Sourcing and Identification at Singapore Shops

Singapore importers occasionally mislabel Geosesarma species because trade-name confusion is widespread. The clean visual cues: Dennerle has bright orange-red claws against dark purple; notophorum is uniformly purple; krathing has vivid red claws against brownish-purple; hagen shows pink-red across both claws and body edges. C328 Clementi, Iwarna and specialty Carousell sellers stock vampire crabs sporadically. Always quarantine new arrivals for two weeks in a temporary brackish setup before introducing to a planted display.

Related Reading

• Fiddler Crab Brackish Care Guide
• Sesarmid Mangrove Crab Care Guide
• Thai Micro Crab Shrimp Tank Cohabitation Guide
• Biotope Mangrove Estuary Paludarium Design Guide
• First Paludarium Build Decision Singapore Guide