Question

Identify the member of the class Scyphozoa.
(a)Silverfish
(b)Jellyfish
(c)Cuttlefish
(d)Catfish

Answer 1

Hint: Scyphozoa is a class under the phylum Cnidaria, that mostly contains aquatic animals. They may also include the extinct group, the Conularidia. The word Scyphozoa comes from the Greek word that denotes a kind of drinking cup shape.

Complete answer:
Jellyfish are mainly marine animals that belong to the class Scyphozoa of the phylum Cnidaria. The class Scyphozoa contains approx. 200 species and they are mostly gelatinous creatures of our world.

Additional Information: From the options in the question, jellyfish belong to the class Scyphozoa. Silverfish are a part of class Insecta and these are small, primitive, wingless insects. Cuttlefish belong to the class cephalopod and are marine mollusks along with squid, octopus, etc. Catfish are chordates of class Actinopterygii. This is a diverse group of ray-finned fish.
Here's some more information about Scyphozoa:
-These are exclusively marine organisms with two life-history phases, one the planktonic medusae or jellyfish form and the other is inconspicuous, long-lived polyp, that gives rise to new medusae.
-These are found in coastal waters throughout the whole world. They are often colorful and large. Scyphozoa typically ranges from 2 to 40 cm in diameter.
-The largest jellyfish Cyanea capillata reaches around 2 meters.
-They eat various crustaceans and fishes as jellyfish capturing those through nematocysts. Nematocysts are located throughout the tentacles.
-Jellyfish are unisexual organisms. The gonads are located in the lining of the stomach and the mature gametes are expelled through the mouth.
So, the correct answer is ‘Jellyfish’.

Note: The Scyphozoa are also called true jellyfish because often people associate them with jellyfish-like creatures such as Portuguese men of war. But these are not true jellyfish. Even though their structure is similar in having a sac-like body with long painful stinging tentacles, it still differs from the true jellyfishes i.e. Scyphozoa.