Meet the bat star

Photo credit: Jerry Kirkhart

Batman is pretty cool, but what about the bat star or Asterina miniata?

A bat star is a type of sea star. You may be wondering if this sea star has bat powers. No, it doesn’t, but it does have cool webbing between its arms reminiscent of the webbing on a bat’s wings, hence the name.

Bat stars live along the ocean floor from Alaska to Baja California. Most of the bat stars I’ve seen are a solid reddish orange or orangish red color, but they do come in a variety of colors including red, orange, purple, yellow, brown and green. Some bat stars have neat multicolored mottled patterns. For example the bat star in the above photo is dark red with a few orange dots speckled in, this is a low-key multicolored look. Other bat stars go all out with several colors combing to light up the ocean waterscape.

Many bat stars live in shallow water close to shore and are commonly found in tidepools, but they are pretty flexible about their water arrangements and have been found living in water up to 950 feet deep. And while bat stars don’t rush to save the day like the superhero with a similar name, they tend not to harm other animals either and instead scavenge for dead or close to dead animals on the sea floor.

The one pretty interesting thing about bat stars is what they do when they meet. If two bat stars happen to bump into each other on the sea floor, each bat star tries putting its arm on top of the other bat star’s arm. It’s not really clear if this is a competition, greeting or what, but it looks like a slow motion “thumb-wrestling” match. Whether either bat star wins or ends up recognizing a long lost cousin isn’t apparent, but it works for them. Maybe they are saying, “No, I’m the best bat star!” (Other bat star slowly raises arm on top.) “No, I’m the best bat star!” And on and on. It must be hard trying to live up to the expectations of the bat star name.


  1. says

    Asterina miniata looks like it fell off a Christmas tree. Researchers say it’s not much of a conversationalist. The only thing we know for sure is that it’s favorite movie is “Over The Top.”

    Yet, as always, you inject humor and life into the lowliest creature. Word on the sea floor is that you rock.

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