Blue Cryptic Sponge Shrimp

Gelastocaris paronai

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Hippolytidae
Genus: Gelastocaris
Species: Gelastocaris paronai

The blue cryptic sponge shrimp (Gelastocaris paronai) is a small shrimp that lives on and matches the colour of blue and purple sponges. Its colour is so close to its host that it is almost invisible.

It grows to about 1-2 cm and clings to the sponge surface, feeding on particles and mucus. It relies entirely on camouflage and seldom leaves its host.

In the Philippines it is found on blue sponges on reefs, where only a slow, close search reveals it.

Photo: Dan Schofield, CC BY 4.0, via iNaturalist