Frequently Asked Questions

Q: What's the world's smallest adult fish?

Stout infantfish Schindleria brevipinguis. H.J. Walker holding specimen from the Marine Vertebrate Collection at Scripps. Photographer - TBA.

A: Depending on how you define "small", it's one of three fish less than a cm long. As of January 2006, the world's tiniest adult fish are among the following species depending on how you define "small" - by length, weight or some other criteria. All of these fish are less than a cm in length, making them the world's smallest vertebrates.

  • A member of the carp family Paedocypris progenetica
  • A male angler fish of the species Photocorynus spiniceps
  • A stout infantfish Schindleria brevipinguis

Q: What kind of fish is in a MacDonald's™ Filet-of-Fish™ sandwich?

A: According to nutrition facts from MacDonald's, the Filet-o-Fish contains "hoki and/or pollock."

Hoki Macruronus novaezelandiae Also known as blue hake, whiptail, blue grenadier, among other names.

Alaska pollock Theragra chalcogramma Also known as Alaska pollock or walleye pollock. In the genus Theragra unlike the Atlantic or European pollocks in the genus Pollachius.

Q: What's the the world's largest adult fish?

A: The world's largest entirely terrestrial fish is the Mekong Giant Catfish. If you include fish that can live in both fresh and marine water, ... The whale shark is the largest fish altogether.