Question

The best characteristic feature of Fish is:
A. Dermal scales
B. Epidermal scales
C. Lateral Line system
D. Both A and C

Answer 1

Hint: Pisces are members of the Chordata phylum of the Animalia kingdom. These are real jawed vertebrates having breathing, excretion, and blood circulation organs. This class of species are poikilotherms, which means they can't regulate their own body temperature. In most cases, the body is streamlined. They have a bony or cartilaginous internal skeleton. Some have a body that is spindle-shaped or elongated. Fresh, marine, and brackish water are all good places to look for them.

Complete answer:
Option A: Fish and some reptiles are the only animals that have dermal scales. Varied species have different sized and shaped scales.
So, option A alone is incorrect.
Option B: Epidermal scales are the protrusion plate-like structure on the body surface, primarily on the outsides of reptiles, birds, and mammals.
So, option B is incorrect.
Option C: A system of sensory organs present in aquatic vertebrates, primarily fish, is known as the lateral line. It detects movement and vibration in the water surrounding it.
So, option C alone is incorrect.
Option D: The only creatures with dermal scales are fish and some reptiles. Scales come in a variety of sizes and shapes, depending on the species. The lateral line is a system of sensory organs found in aquatic vertebrates, especially fish. It detects vibrations and movement in the water around it.
So, option D is correct.

Hence, Option D) is the correct answer.

Note:
The class Osteichthyes includes jawed fish with a bone endoskeleton. It is the most varied group of vertebrates, encompassing both marine and freshwater bony fish. The cartilaginous fishes, which belong to the class Chondrichthyes, are the other group of jawed fishes. Osteichthyes is a group of fish that belongs to the Gnathostomata division, which contains all vertebrates with jaws. Jawless fish are classified as Agnatha and belong to the class Cyclostomata.