Q 01/05

Which organ do jellyfish manage without entirely?

A) Mouth

B) Stomach

C) Brain

D) Tentacles

Answer · why

C) Brain

No jellyfish has a brain; a loose nerve net in the epidermis and a ring nerve around the bell coordinate swimming and feeding instead.

Q 02/05

Jellyfish belong to which phylum, a group they share with the corals?

A) Cnidaria

B) Arthropoda

C) Mollusca

D) Echinodermata

Answer · why

A) Cnidaria

Cnidaria, from the Greek knide for 'nettle', unites jellyfish with corals and hydroids through the stinging cells, the cnidocytes, that every member c...

Q 03/05

Which of these represents a free-swimming larval stage in the life cycle of many jellyfish?

A) Strobila

B) Polyp

C) Medusa

D) Planula

Answer · why

D) Planula

The planula, a tiny cilia-covered larva, swims briefly, then settles as a polyp, which buds off ephyrae that grow into medusae.

Q 04/05

What do most jellyfish mainly eat?

A) Zooplankton

B) Seagrass

C) Kelp

D) Sea sponges

Answer · why

A) Zooplankton

Zooplankton and other tiny drifting animals are the staple, but jellyfish are carnivores that also take fish eggs, larvae, small fish and even other j...

Q 05/05

Which class of jellyfish is traditionally called the 'true jellyfish'?

A) Hydrozoa

B) Cubozoa

C) Staurozoa

D) Scyphozoa

Answer · why

D) Scyphozoa

Scyphozoa, with roughly 200 described species, carries the 'true jellyfish' label by convention; hydrozoan and cubozoan medusae are no less jellyfish.