Strange fish has a see-through head

[The Spartan]

MSNBC.com article

Strange fish has a see-through head
Ultra-sensitive tubular eyes search for the silhouettes of prey overhead
LiveScience
updated 4:32 p.m. CT, Mon., Feb. 23, 2009
A bizarre deep-water fish called the barreleye has a transparent head and tubular eyes. Since the fish's discovery in 1939, biologists have known the eyes were very good at collecting light. But their shape seemed to leave the fish with tunnel vision.

Now scientists say the eyes rotate, allowing the barreleye to see directly forward or look upward through its transparent head .

The barreleye (Macropinna microstoma) is adapted for life in a pitch-black environment of the deep sea , where sunlight does not reach. They use their ultra-sensitive tubular eyes to search for the faint silhouettes of prey overhead.

Scientists had thought the eyes were fixed in an upward gaze, however. This would make it impossible for the fish to see what was directly in front of them, and very difficult for them to capture prey with their small, pointed mouths.

Bruce Robison and Kim Reisenbichler of the Monterey Bay Aquarium Research Institute use videos from the institute's remotely operated vehicles (ROVs) to study barreleyes off Central California. At depths of 2,000 to 2,600 feet (600 to 800 meters), the ROV cameras typically showed these fish hanging motionless in the water, their eyes glowing a vivid green in the ROV's bright lights. The video also revealed a previously undescribed feature of these fish — its eyes are surrounded by a transparent, fluid-filled shield that covers the top of the fish's head.

Most existing descriptions and illustrations of this fish do not show its fluid-filled shield, probably because this fragile structure was destroyed when the fish were brought up from the deep in nets.

Robison and Reisenbichler were fortunate to bring a net-caught barreleye to the surface alive. Over several hours in an aquarium on the ship, they were able to confirm that the fish rotated its tubular eyes as it turned its body from a horizontal to a vertical position.

Barreleyes are thought to eat small fishes and jellyfish. The green pigments in their eyes may filter out sunlight coming directly from the sea surface, helping the barreleye spot the bioluminescent glow of jellies or other animals directly overhead. When it spots prey (such as a drifting jelly), a barreleye rotates its eyes forward and swims upward, in feeding mode.

The findings were detailed recently in the journal Copeia.

Click on the link, the picture with the article is worth the look. This thing is just too bizarre not to share; it just boggles my mind when I think of some of the really weird solutions evolution produces for problems it encounters.

[Kitsune]

I wish the picture was larger or you could click on it and blow it up. As well, some pictures of it in different positions would be real neat

[Zixinus]

My the thing is ugly. Interesting though.

[andrewgpaul]

Another link, with more photos here (courtesy of a link from the Wiki page).

[Surlethe]

Less one-line commentary, more substantial commentary, folks.

[The Spartan]

Another link, with more photos here (courtesy of a link from the Wiki page).

Those are good pictures. Much better than with the article I posted. The face on the thing is so bizarre. It's eerie. It has an almost, well, not human quality to it, but it doesn't look, to me, like the face of a fish. It almost appears, just looking at the face, as some sort of almost malevolent creature that hides behind a deceptively "nice" face.

[Forum Troll]

Now that is cool.

They say it survived for only several hours in a ship-board aquarium. Might be the pressure. If it lives at 600-800 meters depth and is never seen at the surface, it might need 60 atmospheres.

One of the big tourist aquariums ought to make some tanks with thick transparent plastic, pressurized for this and some of the many other interesting exotic deep-sea creatures. Help keep the species preserved by breeding them periodically (like dogs & cats aren't endangered species), and let us see them up close.

[Ariphaos]

Another link, with more photos here (courtesy of a link from the Wiki page).

That video is awesome. "It can also rotate its eyes to avoid predators. Or to avoid being captured by scientists." - as it escapes.

I recall that something along these lines was the given reason for the odd structure of the vertebrate eye - an ancient fish being forced to look through itself leading to all sorts of annoying inefficiencies.

[Kitsune]

I recall that something along these lines was the given reason for the odd structure of the vertebrate eye - an ancient fish being forced to look through itself leading to all sorts of annoying inefficiencies.

An alternate solution. Who is to say that there is a single solution to a problem.
The Panda's thumb is another potential solution and wonder if in a few million years might be able to evolve into something opposable.

One item is that this shows just how tiny a finsh brain is. I guess that kind of lump between the eyes is the brain.

[Fingolfin_Noldor]

Wait, the Fish had no skull!? Is that for real? All brain and no skull?

[AniThyng]

I'm getting the impression the "transparent head" is really just a sort of gelatinous covering over its actual head, and its "eyes" are like, really thick antannae. All this about being able to see the brain and that the fish has no skull seems a tad too hasty and motivated by the wtf factor.

See this: without transparent part

[Junghalli]

The face on the thing is so bizarre. It's eerie. It has an almost, well, not human quality to it, but it doesn't look, to me, like the face of a fish. It almost appears, just looking at the face, as some sort of almost malevolent creature that hides behind a deceptively "nice" face.

The thing is it has what appears to be a normal-looking dolphin-like face with little eyes in the front. Then you see the eyes behind the face and you realize those aren't eyes and that isn't its face at all, just a sort of transparent mask. At least that's my reaction to it. It is really weird.

It's amazing how weird life can get just on this one planet. Really makes you wonder what aliens might look like.

[andrewgpaul]

Those little "eyes" on the front are actually its nostrils.

[Andrew_Fireborn]

Fascinating... Honestly, if the article didn't exist and I'd seen it elsewhere, I'd think it was a photoshop...

Definitely up there on the oddity scale... Although the nostril-eye "face" keeps making my mind doubt. Truely some odd fish out there. Though, personally, I think it's -because- they're fish that they get so odd... I can't see something like this trying to fill a niche on land...

The closest analogy would be a nocturnal predator that for whatever reason fed almost solely on aerial creatures. Possibly some sort of super-frog...

[ArmorPierce]

Those little "eyes" on the front are actually its nostrils.

I was under the impression that fish have gills, not nostrils.

I believe that AniThyng is correct, that's not its skull but some transparent soft tissue on top of its head.

[Erik von Nein]

It's their smell organs. They're called "nares" instead of nostrils or noses.

But, yes, they have gills. They don't have to breathe the water to detect chemicals in the water, merely the water has to wash over them. Which it does.

[Molyneux]

It's their smell organs. They're called "nares" instead of nostrils or noses.

But, yes, they have gills. They don't have to breathe the water to detect chemicals in the water, merely the water has to wash over them. Which it does.

Interesting...I never knew that!
If I recall correctly from a different article, the fish does actually have a rigid skull - it's just transparent. Kind of like having a windshield for a head.

[Darth Yoshi]

Makes sense. Otherwise it'd need an open skull (problematic for obvious reasons) or the water pressure would crush it.

[AniThyng]

The video also revealed a previously undescribed feature of these fish — its eyes are surrounded by a transparent, fluid-filled shield that covers the top of the fish's head.

Most existing descriptions and illustrations of this fish do not show its fluid-filled shield, probably because this fragile structure was destroyed when the fish were brought up from the deep in nets.

I'm pretty sure that the skull and the shield are not the same structure - if you see the diagram where the shield is not present the actual head is pretty obvious - the fish tapers off a lot towards the front.