Question

Palaemon (prawn) belongs to which of the following class?
A. Insect
B. Crustacean
C. Soft-shelled mollusk
D. Fish

Answer 1

Hint: The shrimp belongs to the phylum Arthropoda referring to segmented invertebrates that have an exoskeleton, and a pair of segmented legs. Palaemon is a genus of shrimp.

Complete answer: Arthropoda is a phylum of invertebrate organisms. The word arthropod was derived from two Greek words which meant, “joint foot”. This is because the scientist observed that these organisms had segmented body and joint segmented feet. Another common characteristic of the Arthropoda is they possess an exoskeleton. Insects, arachnids, myriapods, and crustaceans belong to the phylum of Arthropoda. The Palaemon shrimp is a genus of seawater shrimp that belongs to the phylum Arthropoda and subphylum Crustacea. Crustaceans include shrimp, crab, lobster, krill, and barnacles. Most crustaceans are aquatic organisms but some are terrestrial such as woodlice. This subphylum of Arthropoda possesses a segmented body, an exoskeleton made up of chitin, and a pair of joint legs.
Therefore, the correct answer is B.

Note: Invertebrates with a segmented body refer to a morphological structure where each portion is a segment and multiple segments joined together to make the entire body of the organism. This can be seen in shrimps, prawns, in the case of crustacea. Butterflies, ants, and wasps in the case of insects, and spiders in the case of arachnids. Soft-shelled mollusks do not possess a continuous exoskeleton and rely on calcified shells for protection whereas crustaceans have a joint exoskeleton made up of organic matter like chitin.