Final answer:
The major classes within the subphylum Crustacea typically include Malacostraca, which comprises animals like crabs and lobsters; Branchiopoda, known for freshwater species; Maxillopoda, which encompasses barnacles; and Ostracoda, small crustaceans called seed shrimp.
Step-by-step explanation:
Major Classes Within the Subphylum Crustacea
The subphylum Crustacea includes a vast array of aquatic and a few terrestrial arthropods. Some of the most well-known members of this group include krill, shrimp, lobsters, crabs, and crayfish. Among the terrestrial species, organisms such as the woodlice, also known by various names like pill bugs or roly-polies, represent the Crustacea on land.
Main Classes of Crustacea
The major classes within the subphylum Crustacea are not specifically listed in the provided references, but common classes generally include:
- Malacostraca: This is the largest class of Crustacea, which includes crabs, lobsters, krill, shrimp, and crayfish.
- Branchiopoda: Includes brine shrimp and other primarily freshwater crustaceans.
- Maxillopoda: Includes a diverse group such as barnacles and copepods.
- Ostracoda: Small crustaceans often referred to as seed shrimp due to their size and shape.
These various classes of Crustaceans are adapted to a range of environments, with many aquatic species but also some like pill bugs that are found on land.