Weird Wonderful Wildlife #15 – The Chimera

In Greek mythology, a chimera was a creature made up of parts of different animals, which makes it the perfect name for this elusive sea creature. Also known as a ghost shark, the chimera blends characteristics of mammals, sharks and rays into one bizarre looking, but completely harmless fish. There are three groups of chimera – long nosed, short nosed and plow nosed. They live on the deep sea floor and can become quite large because they have little competition for resources and have quite a bit of space in which to flourish. Like sharks, female chimera lay eggs on seaweed or other substrata; the egg cases can be found on beaches and are called mermaid’s purses. They eat other fish, squid and worms, and will also opportunistically feed on dead animals as well. Chimera have a number of bizarre features which include:

• they have true nostrils but also one gill on each side of their bodies; the nostrils draw in water that passes over the gills;
• their upper jaw is fused to their skull;
• they have three rows of permanent rodent-like teeth;
• they have no scales
• their eyes are backed with a reflective tissue layer that makes it easier for them to see and which also makes their eyes appear to glow in the dark; and
• they have wing like pectoral fins similar to a ray which help them travel longer distances while conserving energy which is helpful for hunting.

It’s believed that the chimera evolved about 360 million years ago but the earliest known fossil specimen can only be dated to about 280 million years ago. Regardless of it’s true age, the chimera has the slowest evolving genome of any vertebrate, making them true living fossils. Somehow I think if you can trace your lineage to the time of the dinosaurs, you’ve definitely earned the right to chill on the ocean floor.

Sources

sharkangels.org/species-in-focus/ghost-shark

naturalworldfacts.com/deep-sea-wonders-2/ghost-sharks