They may look pretty -- but these lionfish are predatory and venomous.
And are wreaking havoc off the coast of Lebanon.
Fisherman Hassan Younes has been diving the same waters off his coastal hometown for three decades.
He has never seen anything like this.
Native species are disappearing and invasive lionfish are taking their place.
(SOUNDBITE) (Arabic) LEBANESE FISHERMAN, HASSAN YOUNES, SAYING:
"Many times, and it is not just me, many fishermen are the same, we go out to sea and come back empty-handed because there is little fish."
There are however plenty of lionfish.
Native to the Red Sea, and the Indo-Pacific region, they are pretty good at eating.
(SOUNDBITE) (Arabic) FISHERMAN, ATALLAH SIBLINI, SAYING:
"This fish is like genocide. It settles and takes up the place of everything. It does not coexist with along with other fish. They mainly live where the sea bass does so sea bass numbers have radically decreased. They eat everything, they even eat each other if they can't find anything to eat."
Experts say they've spread for a number of reasons.
The expansion of the Suez Canal which connects the Red Sea and the Mediterranean is one.
And warming waters as a result of climate change -- another.
They are threatening coral reefs and fish stocks.
Lebanese waters are already weakened by overfishing and pollution.
But there may be a solution... eating them.
Environmentalists in Lebanon say the livelihoods of the fishermen and the survival of the marine ecosystem may depend on it.
(SOUNDBITE) (Arabic) ENVIRONMENTALIST, JINA TALJ, SAYING:
"Luckily for us, it is also one of the tastiest types of fish today in the sea and we are encouraging the fishermen and people to ask for it in restaurants and fish markets."