Cactus Shrimp

Pontonides maldivensis

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Palaemonidae
Genus: Pontonides
Species: Pontonides maldivensis

The cactus shrimp (Pontonides maldivensis) is a tiny shrimp that lives on black corals and sea whips, its body covered in bumps that mimic the host's polyps. Its colour usually matches its host, from yellow and green to brown or white.

It grows to only about 1 cm and sits pressed against the stem of its coral, where it is nearly invisible. It feeds on mucus and particles caught on the coral surface, and pairs often share a single host.

Black corals and whip corals on walls and slopes in the Philippines are good places to look for the cactus shrimp. Following a stem slowly from base to tip is often the only way to find one.