Tiny, mussel-invading crab named after Roman god

WASHINGTON, Oct. 24 (UPI) -- Every once in a while, oyster-eaters, clam-eaters and consumers of other bivalves may happen upon a tiny, nearly transparent crab. While these parasitic stowaways may all look the same, there are a variety of species.

Recently, biologists discovered a new species of pea-sized crab living in large date mussels along the coast of the Solomon Islands. The crab has an extra plate covering its upper dorsal, or carapace, offering the illusion of an additional face. Thus, the crab's discoverers decided to name the species after Janus, the two-faced Roman god.

Serenotheres janus is described in a new study, published this week in the journal ZooKeys.

The crab was discovered and described by marine biologists Peter Ng, from the National University of Singapore, and Christopher Meyer, a researcher at the Smithsonian Institution's National Museum of Natural History.

The newly named crab species is only the second member of the Serenotheres genus. The first was discovered in Malaysia. The cream yellow tint of its exoskeleton and a broader extra carapace distinguish Serenotheres janus from its closest relative.

Further research is needed to determine the evolutionary purpose of the added carapace.