Is this a lion fish? How can I tell if it's a lionfish or scorpion fish?

imgur: the simple image sharer

I took this picture of what I believe is a lionfish while snorkeling in Cozumel in 2010. At the time I didn't know that lionfish were an invasive species and that I should have notified someone at the hotel about it.

Now that I'm certified I want to be on the lookout for them.

How can I tell the difference from a scorpionfish?

Although not as colorful as the Lionfish I have seen, this certainly looks like a lionfish to me.

Yes, it's a juvenile common lionfish. Lionfish have those long, feathery fins and they often swim or hover in the water column, sometimes in groups. They are quite "showy" fish. Scorpionfish are very mimetic and look pretty much like the rock they are perched on; they're solitary. You rarely see them swimming at all, and generally their dorsal fins (where the spines are) are not raised. It's often hard to even discern that they're there.

Quero:

Scorpionfish are very mimetic and look pretty much like the rock they are perched on; they're solitary. You rarely see them swimming at all, and generally their dorsal fins (where the spines are) are not raised. It's often hard to even discern that they're there.

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Here are a couple of pics I took of a Scorpion Fish in Grand Cayman. You can see how they camouflage into their surroundings, and what one looks like when it's moving.

That is lionfish, but I was wondering why you asked so I looked on Wikipedia for Scorpionfish.

Scorpaenidae - Wikipedia, the free encyclopedia: Scorpaenidae (scorpionfish) family includes the lionfish and stonefish.

Scorpaenidae, the scorpionfish, are a family of mostly marine fish that includes many of the world's most venomous species. As the name suggests, scorpionfish have a type of "sting" in the form of the sharp spines coated with venomous muscus. The family is a large one, with hundreds of members. They are widespread in tropical and temperate seas, but mostly found in the Indo-Pacific. They should not be onfused with cabezones, of the genus Scorpeanichthys, which belong to a seperate, though related family, Cottidae.

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In North America we have a fish called scorpion fish. Cabezon (fish) - Wikipedia, the free encyclopedia (I have see this fish before many times.)

I wonder if the Cabezon fish is venomous or not. Does not sound like it is.

Yes, that is a lionfish. They can appear brown, black or red. Now that you know what they are, you can carry a marker so you will know where they are when you report them. We make them using a large washer (any weight source would do), a length of yellow surveyors tape (about an inch wide and 3 feet long) and a wine cork. Tie one end of the tape to the weight, poke a hole through the cork and run the tape through, tie a good knot. Easy to carry and drop near the fish. Be sure to record depth and a way to tell where the site is. (compass readings, 12 minutes into dive, near the big barrel sponge, etc).

We have been killing them off in the caribbean for a few years now. They have been found all the way to New Jersey and above. Most of the fish above North Carolina will die in the winter due to the cold. You can do an internet search to learn more about this beautiful but destructive (outside of the Indo Pacific) fish.