Q 01/05

Which reef fish, made famous by Finding Nemo, has a breeding male that turns female when the group's female dies?

A) Blue tang

B) Clownfish

C) Moorish idol

D) Pufferfish

Answer · why

B) Clownfish

Clownfish live in a strict size ranking around one anemone, so when the female is lost the male changes sex and the largest non-breeder steps up as th...

Q 02/05

In which fish does the male carry the female's eggs in a pouch on his body until they hatch?

A) Stickleback

B) Mudskipper

C) Lionfish

D) Seahorse

Answer · why

D) Seahorse

Seahorse fathers carry the eggs for 9 to 45 days, then release fully formed but very small young into the water.

Q 03/05

Which sea animal has a species nicknamed 'immortal' because the adult can revert to its juvenile polyp stage?

A) Jellyfish

B) Starfish

C) Sea urchin

D) Lobster

Answer · why

A) Jellyfish

Jellyfish of the species Turritopsis dohrnii can turn back into a seabed-bound polyp after reaching maturity, then grow up all over again.

Q 04/05

Which cold-water fish, the longest-lived vertebrate known, is thought to reach breeding age at around 150 years old?

A) Greenland shark

B) Arctic char

C) Atlantic halibut

D) Beluga sturgeon

Answer · why

A) Greenland shark

Greenland shark lifespans are estimated at 272 years or more, and the pups are born alive after a pregnancy thought to last 8 to 18 years.

Q 05/05

Which North American insects spend 13 or 17 years underground as juveniles before emerging together in huge broods?

A) Fireflies

B) Cicadas

C) Crickets

D) Katydids

Answer · why

B) Cicadas

Cicadas of the periodical kind may owe those prime-number waits to their enemies: one idea is that 13 and 17 years are hard for predators with shorter...