Octiria?

  

Yes, you saw that right.  This Bat Star (Patiria miniata) has eight arms!  They typically have five.  We've seen them with six, and once we found one with seven arms (see "7 for the 7th" on 7 March 2017).  This is the first Bat Star we've seen with 8 arms.  (Just for fun, we've been calling it "Octiria" instead of Patiria.)

Many thanks to Sam for spotting this unusual specimen and sharing this great photo!

P.S.  For the record, we've also found an 8-armed Ochre Sea Star (Pisaster ochraceus) — see "Octoaster?" on 29 April 2020.