Key to the species of the genus Hamopontonia Bruce, 1970

1. Distal margin of telson with small blunt median process between hook-like distolateral processes. Small species; with translucent body and appendages covered with numerous tiny red dots. Associated with Stylophora pistillata ( Scleractinia, Pocilloporidae)............................................................ Hamopontonia essingtoni Bruce, 1986

– Distal margin of the telson without blunt median process between hook-like distolateral processes. Medium sized species associated with other scleratinian corals...................................................................... 2

2. Pereiopods II equal in size. Colored with two large dorsal uniformly white of creamy white irregular patches on carapace and abdominal somites. Associated with fungiid corals, mainly with Heliofungia actiniformis Hamopontonia fungicola sp. nov.

– Pereiopods II unequal in size. Different colour pattern and associated with different host........................... 3

3. Rostrum with well developed deep dorsal carina. Dorsal surface of carapace and abdomen covered with single large circle whitish or creamy-white patch consisting of several small spots in the centre fringed with white broad band. Associated with caryophyllid coral Physogyra lichtensteini ..................................... Hamopontonia physogyra sp. nov.

– Rostrum with shallow dorsal carina. Dorsal surface of carapace and each abdominal somite I–IV covered with subcircular or oval patches consisting of a red colored centre fringed with a broad creamy white band. Associated with poritid corals Goniopora spp....................................................... Hamopontonia corallicola Bruce, 1970