True fishes have fins and gills. This is not a true fish

The correct option is Lepisma – Silverfish.

To understand why this option is correct, let us analyze the characteristics of true fishes versus the silverfish:
1. Characteristics of True Fishes: True fishes belong to the superclass Pisces (within the phylum Chordata). They are aquatic, gill-bearing, craniate animals that lack limbs with digits. Instead, they possess fins for swimming and balance, and gills for extracting oxygen from water. Examples of true fishes include:

• Hippocampus (Sea Horse): A true bony fish belonging to the family Syngnathidae.
• Hypophthalmichthys (Silver carp): A true freshwater cyprinid fish.
• Carassius (Goldfish): A true freshwater bony fish.

2. Characteristics of Lepisma (Silverfish): Despite its common name containing the word "fish," Lepisma saccharina (commonly known as a silverfish) is actually a small, wingless insect belonging to the order Zygentoma (formerly Thysanura) in the phylum Arthropoda.
Since it is an insect, it does not possess fins or gills, nor does it belong to the class of fishes. It has a silvery-grey, fish-like appearance and moves in a wiggling motion resembling a swimming fish, which is how it got its misleading common name.

Therefore, Lepisma – Silverfish is not a true fish.