Which term describes the arthropod group that includes lobsters, crabs, shrimps, and barnacles?

• A. Crustaceans
• B. Arachnids
• C. Insects
• D. Decomposers

Answer: (A)

Lobsters, crabs, shrimps, and barnacles share classification as crustaceans, a major subgroup of arthropods. Crustaceans are typically aquatic and have a hard exoskeleton, segmented bodies, and paired appendages, often with two antennae and gills for breathing. Barnacles are crustaceans that have adapted to a sessile lifestyle, while lobsters, crabs, and shrimps are mobile and belong to the group commonly called decapods. In contrast, arachnids like spiders and scorpions have eight legs and no antennae, insects have six legs and often wings, and decomposers describe a functional role rather than a specific lineage. So, the term that best describes this arthropod group is crustaceans.