Blue is associated with "rarity," as in the idiom "once in a blue moon." When French fishmongers recently caught a blue lobster, they decided not to sell it.

Lobsters are usually brownish and turn bright red when cooked. The chance of finding a blue one, according to Les Viviers de Noirmoutier, a seafood retailer in France, is one in two million, CBS News reported.

After consulting the tourism office on the Île d'Yeu, the fishermen decided to release the small female lobster on the coast of Saint-Gilles, where Les Viviers is located. Its new home is a non-fishing area where it can live a long, peaceful, and happy life, the Les Viviers' Facebook post reads, according to CBS News.

As rare as blue lobsters are, new creatures recently discovered by entomologists in a mangrove forest in southern Thailand.

In an article about their discovery reported by CBS News, the researchers from the Entomology Museum at Khon Kaen University and the Natural History Museum of the National Science Museum described the new species' blue coloration as "electrifying," an "enchanting phenomenon" and fascinating.

The hue of the Chilobrachys natanicharum, which are tarantulas, resembles electrical sparks. Its blue-purple hair on its legs and body is "iridescent."

The habitat of electric blue tarantulas must be preserved and protected. Otherwise, the unusual arachnids would be like blue lobsters, seen only once in a blue moon.