Also known as firefish, the lionfish (or Pterois Volitans) ranges from 30 to 40 cm long and feeds mainly on fish and shellfish. The video above, shot in the Bahamas in June 2009, allows you to discover the beauty of this fish that likes to position itself vertically, head up or upside down. If it is certainly beautiful, it is also very dangerous since with its dorsal fin spines he is able to inflict venomous stings that can be fatal for humans.

Since the early 2000s, I have been diving frequently in the Gulf of Mexico on wrecks near Anna Maria Island off Tampa bay (West Coast of Florida) and have never seen lionfish before 2015. Proof if any were needed of the invasion of Florida waters by this species, the above video was shot in August 2017 on the wreckage of an old tugboat.

LIONFISH

    Though native to the Indo-Pacific, the lionfish found its way in the 90's to the East Coast of the US and to the Caraibs and it is now causing some great concern since it does not seem to have any predator.

"It all started back in 2002 when local divers off the coast of North Carolina have spotted a group of lionfish... The divers were perplexed by such an unusual discovery and have collected an actual specimen, which became the first solid evidence of lionfish spreading in the Atlantic....According to NOAA, these pervasive creatures have become well established in Bermuda, the Bahamas, Cuba, the Dominican Republic, Jamaica, Puerto Rico, Turks and Caicos, and the Cayman Islands. There are also reported sightings in Belize, Haiti, U.S. Virgin Islands, Mexico, Aruba, Curacao, and Bonaire....there is a hypothesis that their initial introduction has occurred during Hurricane Andrew in 1992 when at least six lionfish escaped from a broken beachside aquarium near Biscayne Bay. The genetic testing supports this theory. It is also likely that continued release of unwanted lionfish by aquarium enthusiasts caused additional introductions and range expansion of the lionfish. With no natural enemies and an extremely high reproductive rate of 2 million eggs a year from one female, lionfish have spread rapidly through the South Florida Estuaries, the Gulf of Mexico and the Caribbean Sea. Although now the colder water temperatures are keeping their numbers in check to the north, warming ocean conditions may permanently expand the range of this fish along much of the eastern coast of the United States."

    From the Gulf and Caribbean Fisheries Institute (GFCI), a timeline of the lionfish invasion running from 1985 to 2014 is available on this page (see this link). It gives a pretty good idea on how fast was this invasion.
    With Pterois volitans invading into the Gulf of Mexico and the West Atlantic, there is also at the same moment the invasion of the Mediterranean Sea by another species of lionfish known as Pterois miles according to data from DORIS (see this link) a french organization dedicated to the observation of marine species: with a naked eye it is practically impossible to distinguish Pterois volitans from Pterois miles. The second comes from the Red Sea and the western Indian Ocean while the first one comes from the eastern Indian Ocean and especially the Pacific Ocean. These 2 species have long been considered as a simple geographical variation, but today genetic studies have shown differences and they are recognized as 2 distinct species. Pterois miles were observed in 2016 in marine protected areas off Cyprus and Turkey, but previously in 1991 off Israel and in 2012 off Lebanon. "The invasion is in progress" in the Eastern Mediterranean, confirmed in 2018 Jason Hall-Spencer, professor at the British University of Plymouth. This is explained by the warming temperatures and the fact that the Suez Canal, which has been expanding since 2015, linking the Mediterranean Sea with the warmer Red Sea, has facilitated the arrival of fish from elsewhere in Mediterranean waters. Cooler, the western Mediterranean is currently spared, says Demetris Kletou, scientific coordinator of Relionmed, a pilot project on the lionfish that aims to make Cyprus "the first line of defense" against the colonizer.
    With no known predator, the lionfish being a voracious eater who is not particularly selective when it comes to consuming fishes and reproducing at an incredibly high rate, he is a major threat to local species in areas where he is expanding.
    As of today, the following link gives the most complete up-to-date status about this ecologic threat and existing ways to thwart it.