CR

Ceylonthelphusa callista

Unknown

Overview

A detailed profile for this species is sourced from the IUCN Red List of Threatened Species as assessments become available.

Ceylonthelphusa callista faces severe threats from habitat degradation in Sri Lanka's freshwater systems. Agricultural runoff and urban development have contaminated the pristine mountain streams this endemic crab depends on for survival. Deforestation in watershed areas has altered water flow patterns and increased sedimentation, while collection pressure for the aquarium trade has further reduced wild populations.

Threat summary

Habitat

This endemic freshwater crab inhabits clear, fast-flowing mountain streams and rivers in Sri Lanka's central highlands. It requires well-oxygenated waters with rocky substrates and overhanging vegetation that provide shelter and maintain cool water temperatures.

Wetlands (inland)· majorWetlands (inland) - Permanent rivers/streams· major

Conservation measures underway

Site/area protection

Other threatened species in GECARCINUCIDAE

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Irmengardia nemestrinus

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Somanniathelphusa zanklon

Unknown
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Parathelphusa nagasakti

Declining
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Lepidothelphusa cognetti

Unknown

Threatened in Sri Lanka

Indian Star TortoiseVU

Indian Star Tortoise

Geochelone elegans

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Ceylonosticta nietneri

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Lipstick Goby

Sicyopus jonklaasi

Declining
EN

Martenstyni's Barb

Systomus martenstyni

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Frequently asked questions

Why is Ceylonthelphusa callista classified as Critically Endangered?
Ceylonthelphusa callista is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. Ceylonthelphusa callista faces severe threats from habitat degradation in Sri Lanka's freshwater systems. Agricultural runoff and urban development have contaminated the pristine mountain streams this endemic crab depends on for survival. Deforestation in watershed areas has altered water flow patterns and increased sedimentation, while collection pressure for the aquarium trade has further reduced wild populations.
Where does Ceylonthelphusa callista live?
Ceylonthelphusa callista occurs in Sri Lanka. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Ceylonthelphusa callista?
The main threats to Ceylonthelphusa callista are ai-1, ai-2, ai-3, and ai-4. The full IUCN-classified threat record for this species is detailed on the species page.

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