Which fish is famously known for 'cleaning' algae off aquarium glass surfaces?

Plecostomus

In "Star Wars," who shot first according to original theatrical release: Han or Greedo? What is the phobia of Halloween called? The mask used in 'Scream' films is based on what painting? Who was the first U.S. Cabinet member to be convicted of a felony for the Teapot Dome Scandal? What do mathematicians call a pair of angles whose measures add up to 180 degrees?