Thecostraca

Thecostraca is a subclass within the class Maxillopoda, a group of crustaceans. This subclass includes some of the most familiar and economically important marine species, such as barnacles and tongue worms. These organisms are characterized by their unique, often sessile (non-moving) lifestyles and specialized feeding strategies. Thecostracans are diverse and widespread, inhabiting a variety of marine environments from shallow coastal waters to the deep sea.

Common Names

Thecostraca are commonly known as barnacles or tongue worms. However, this classification encompasses a wide variety of species, each with its own unique morphology and biology.

Characteristics

Thecostraca exhibit several distinct characteristics that differentiate them from other crustaceans:

  • Sessile lifestyle: Most thecostracans are sedentary, attaching themselves to surfaces such as rocks, ships, or marine animals.
  • Calcified shell: Many thecostracans have a hard, calcified shell that protects their bodies.
  • Modified appendages: Their appendages are often specialized for feeding, locomotion, or attachment.
  • Parasitic relationships: Some thecostracans, such as tongue worms, are parasitic and live within the bodies of other marine animals.

Environments

Thecostracans are found in a wide range of marine environments, including:

  • Intertidal zones: Barnacles are common in the intertidal zone, where they are exposed to both air and water.
  • Subtidal zones: Some thecostracans live in deeper waters, attached to rocks, corals, or other substrates.
  • Pelagic zone: A few species, such as the barnacle Lepas anatifera, are pelagic and live in the open ocean.

References

For further information about Thecostraca, refer to these reliable sources: