Problem 122 - Objective Biology for NEET

Question

Which of the following is not a fish? (a) Devil fish (b) Cuttle fish (c) Jelly fish (d) All of these

Step-by-Step Solution

Answer

All of these are not true fish.

Step 1: Identify the Species

Have a look at the given options, namely: Devil fish, Cuttle fish, Jelly fish. Research or recall information regarding these species.

Step 2: Classify the Species

Classify each species based on its characteristics and habitat. Devil fish is a type of ray, Cuttle fish is actually a type of mollusk, and Jelly fish is a type of invertebrate.

Step 3: Compare with Fish Characteristics

Compare the characteristics of these species with the characteristics of genuine fish. Fish are vertebrates that live in water and have gills to breathe. None of these species have the exact traits of fish.

Key Concepts

Fish Characteristics

Fish are fascinating creatures that live in water and are vertebrates, meaning they have a backbone. They breathe using gills instead of lungs, which allow them to extract oxygen from water. Fish have scales covering their bodies and fins to help them move through water. They are cold-blooded animals, which means their body temperature is regulated by the surrounding environment.
Fish can be found in various types of water bodies, from oceans to freshwater streams. There are numerous species of fish, each adapted to its specific environment. They play diverse roles in the aquatic ecosystem, from predators to prey. Some common examples of fish include tuna, salmon, and goldfish.

• Vertebrates with a backbone
• Breathe through gills
• Body covered with scales
• Cold-blooded

Invertebrates

Invertebrates are animals that do not have a backbone. These creatures form the vast majority of the animal kingdom and showcase incredible diversity. Examples include insects, arachnids, snails, and jellyfish. Due to the absence of a backbone, invertebrates rely on different forms of body support, such as exoskeletons or hydrostatic structures.
Jellyfish as Invertebrates
Jellyfish are intriguing invertebrates that drift through ocean currents. They have a soft, gelatinous body and long tentacles, which they use for defense and capturing prey. Jellyfish move by contracting their bell-shaped body, propelling themselves through water. They thrive in a variety of ocean environments and are known for their stunning appearances.

• No backbone
• Variety in form and habitat
• Support structures like exoskeletons
• Includes jellyfish

Mollusk

Mollusks are a diverse group of invertebrates characterized by a soft body, often protected by a hard shell. They include creatures like snails, clams, and cuttlefish. Cuttlefish, despite their name, are not fish but belong to this group. These animals have a distinct, flexible body plan that allows them to adapt to various environments.

Cuttlefish Characteristics

Cuttlefish are known for their remarkable ability to change color and texture, a skill used for camouflage, communication, and predation. They have excellent vision that helps them hunt for prey. Their bodies include a unique internal shell, called a cuttlebone, which aids in buoyancy control.

• Soft body, often with a shell
• Includes snails, clams, and cuttlefish
• Adapted to different habitats
• Cuttlefish can change color and texture