In News:

Researchers recently documented unusual predatory behaviour of a horn-eyed ghost crab at Rushikonda Beach, Visakhapatnam, drawing attention to the ecological role of ghost crabs in coastal ecosystems.

Taxonomy

• Belongs to the genus Ocypode
• Commonly known as ghost crabs due to their pale colour and rapid, almost “vanishing” movements on beaches

Habitat

• Found primarily in sandy intertidal zones
• Builds deep burrows above the high-tide line on beaches
• Most active during dawn, dusk, and night, avoiding daytime heat

Distribution

• Occurs widely across the Indo-Pacific region
• Range extends from the east coast of Africa to the Philippines, and from Japan to the Great Barrier Reef
• Absent in the Red Sea
• Six species of ghost crabs have been recorded along the Indian coastline

Physical and Behavioural Features

• Pale, sand-coloured body helps in camouflage against predators
• Possesses long legs adapted for fast sideways running
• The term “horn-eyed” refers to eye stalks that may appear elongated or horn-like
• Known for agile hunting and burrow-dwelling behaviour

Feeding Habits

Although traditionally considered scavengers, recent observations show active predation.

Diet includes:

• Clams
• Snails
• Marine worms
• Isopods
• Shrimps
• Insects
• Other crabs, including small hermit crabs

This highlights their role not just as scavengers but also as important predators in beach ecosystems.

Ecological Role

Horn-eyed ghost crabs are considered:

• Keystone species in sandy shore ecosystems
• Bio-indicators of coastal health

Why important?

• Their burrowing activity aerates sand and influences sediment structure
• Their feeding controls populations of smaller invertebrates
• Healthy ghost crab populations generally indicate less-disturbed beaches

Threats

Ghost crabs are sensitive to environmental disturbances. Major threats include:

• Coastal pollution
• Beach tourism and human trampling
• Changes in sediment patterns due to erosion or construction
• Rising sea temperatures
• Altered tidal cycles due to climate change

Such pressures may force them to shift habitats in search of food and suitable burrowing sites.