Because there are so many weird fish out there, I’ve narrowed this week’s episode down to weird BIG fish! We’ll cover the smaller ones another time. Thanks to Damian and Sam for suggestions this week!

A manta ray being interviewed by a diver:

A manta ray with white markings:

A mola mola, pancake of the sea, with a diver:

The flathead catfish head. So many teeth:

A Wels catfish with Jeremy Wade:

A couple of red cornetfish:

Howick Falls in South Africa. Put that on my endless list of places I want to visit:

Further reading:

Karl Shuker's blog post about the black and white manta rays

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s another listener suggestion week! Recently, Damian sent a list of excellent topic suggestions, one of which was weirdest fish, and I am ALL OVER that! But because there are so many weird fish, I’m going to only look at weird humongous fish this time, including a mystery fish.

We’ll start with a fish that doesn’t actually look very fishlike. Rays are closely related to sharks but if you didn’t know what they were and saw one, you’d probably start to freak out and think you were seeing some kind of water alien or a sea monster. The ray has a broad, flattened body that extends on both sides into wings that it uses to fly through the water, so to speak. The wings are actually fins, although they don’t look like most fish fins. Like sharks, rays have no bones, only cartilage. Rays are so weird that I’m probably going to give them their own episode one day, but for now let’s just look at one, the manta ray.

There are two species of manta ray alive today. The reef manta can grow 18 feet from wingtip to wingtip, or 5.5 meters. Manta birostris is even bigger, up to 29 feet across, or 8.8 meters, which is why it’s called the giant manta ray. This is just colossally huge. I didn’t realize how big manta rays were until just now. Both species live in warm oceans throughout the world and both eat plankton, krill, and tiny fish. Sometimes the manta ray is called the devil fish because of its horns, which aren’t horns at all, of course. The two protuberances that stick forward at the manta ray’s front are actually fins that grow on either side of the rectangular mouth. These fins help direct plankton into the mouth. When the manta ray isn’t feeding, it can roll up these fins into points and close its mouth. Its eyes are on the sides of its head.

Manta rays are white underneath and black or dark brown on top. But there is a mystery associated with the giant manta ray, with reports of black and white striped rays dating back to at least 1923. In April of that year, naturalist William Beebe spotted a manta ray near the Galapagos Islands that had white wingtips and a pair of broad white stripes extending from the sides of the head halfway down the back. Beebe thought it might be a new species of manta ray. There are other reports of manta rays with white or grayish V-shaped markings on the back.

Better than that, in the last few decades divers and boaters started to get photographs and even video of these manta rays with white markings. These days, manta rays with white markings are known to be common, although for decades scientists thought all manta rays were unmarked dorsally, or on the back. Since the markings are unique to individuals, it makes it easy for researchers to track individuals they recognize. The manta ray also sometimes has black speckles or blotches on its belly.

But wait, there’s more! According to zoologist Karl Shuker, in 2014, researchers in Florida published a paper discussing the ability of manta rays to actually CHANGE COLOR in minutes when they want to. The color in question that it changes? Its white markings. The markings can be barely visible against its background color, and then will brighten considerably when other manta rays are around or when it’s feeding.