In basic animal classification, prawns belong to which major group of animals?

Introduction / Context:
Prawns are familiar seafood items and are often confused with fishes by people who do not study zoology in detail. However, from the point of view of biology and classification, prawns are very different from true fishes. Many objective questions test whether you can correctly place prawns in their proper animal group. This requires a basic understanding of arthropods and their subgroups.

Given Data / Assumptions:

• The question asks which major animal group prawns belong to.
• Options include crustaceans, fishes, amphibians, and reptiles.
• We assume basic knowledge of vertebrates and invertebrates.

Concept / Approach:
Prawns are invertebrate animals that belong to phylum Arthropoda, class Crustacea. Crustaceans are characterised by a hard chitinous exoskeleton, jointed appendages, and often two pairs of antennae. The body is typically divided into cephalothorax and abdomen. Fishes, by contrast, are vertebrates with a backbone, internal skeleton, gills, and fins. Amphibians and reptiles are also vertebrates with distinct life histories and skin coverings, quite different from prawns. Therefore, prawns are correctly classified as crustaceans, not as fishes or other vertebrates.

Step-by-Step Solution:
Step 1: Note that prawns have an external shell and jointed legs, a hallmark of arthropods. Step 2: Recall that crustaceans are a major subgroup of arthropods that includes prawns, crabs, lobsters, and shrimps. Step 3: Recognise that fishes, amphibians, and reptiles all have an internal bony or cartilaginous skeleton and a vertebral column. Step 4: Understand that prawns do not have a backbone and therefore cannot be categorized as vertebrate fishes or reptiles. Step 5: Select crustaceans as the correct group for prawns in basic animal classification.

Verification / Alternative check:
Taxonomy references list prawns under class Crustacea within phylum Arthropoda. Diagrams show features like compound eyes, segmented body, swimmerets, and gills attached to appendages. Fisheries biology texts refer to prawns as crustacean shellfish, distinct from finfish. These consistent sources confirm that prawns are crustaceans rather than fishes or amphibians, validating the correct option.

Why Other Options Are Wrong:

• Fishes, aquatic vertebrates with gills and fins: While prawns are aquatic, they lack a vertebral column and internal skeleton, so they are not fishes.
• Amphibians, vertebrates that live both in water and on land: Amphibians include frogs and salamanders, not prawns.
• Reptiles, cold blooded vertebrates with scales and shelled eggs: Reptiles include snakes, lizards, and turtles, not crustacean shellfish.

Common Pitfalls:
Because prawns live in water and are eaten along with fish, many people casually think of them as a type of fish. Examinations often exploit this confusion. To avoid this mistake, always remember that having an external shell and jointed legs indicates an arthropod, and prawns specifically are crustaceans. Linking familiar seafood like crab, lobster, and prawn together in your memory as crustaceans can make recall much easier.

Final Answer:
Prawns belong to the group of animals known as crustaceans, a subgroup of arthropods with hard exoskeleton and jointed appendages.