From the movie Dagon
From the classic Bride of Frankenstein
From the movie Analyze This; Robert de Niro and Billy Crystal talk in front of an aquarium in which two young ladies dressed as mermaids cavort
From the movie Night Tide
Screen captures from various commercials.
Screen captures from various cartoons, including Go, Diego, Go!, Dora the Explorer, Little Bear, and Backyardigans.
Screen captures from various documentaries, including Miami Ink and the History Channel's documentary World War I. (The caps are of a propaganda movie of the time where King Neptune is informed by mermaids of Britain's peril and goes to the surface to exhort the British to buy war bonds.)
Movie screencaps from The Thirteenth Year, Enchanted, Local Hero, Roxy Hunter and the Myth of the Mermaid, Beach Blanket Bingo, the TV movie Princess, and Viva Maria starring Brigitte Bardot.
Music video screencaps. Songs include Oo-ee-diddly-bop, No Ordinary Love by Sade, Cherish and Dear Jessie by Madonna, Low C by Supergrass, and One in a Million Girls.
Screencaps from the anime Pet Shop of Horrors.
TV screencaps.