silverfish,cuttlefish,jellyfish,starfish,dogfish,crayfish which is the odd one and why

Hi Piya Roy,
Answer is Dog Fish-Squalus (scientific name)
In the given options all are not fishes except Dog fish

Silver fish-belongs to Arthropoda phylla-Not a fish
Cuttle fish- belongs to Molluscan-Not a fish
Jellyfish- belongs to Cnidarian-Not a fish
starfish- belongs to Echinodermata- Not a fish
Dog fish-belongs to Pisces
cray fish- belongs to Arthropoda-Not a fish