Conchostracans

Conchostracans, also known as clam shrimp or seed shrimp, are a diverse group of small freshwater crustaceans belonging to the subclass conchostraca. They are characterized by their bivalved carapace, which encloses their entire body and resembles that of a clam or mussel, hence the common name. This shell is typically thin, translucent, and lacks hinges, being held together by muscles. Conchostracans are found in temporary freshwater habitats such as ponds, puddles, and ephemeral lakes worldwide. Their eggs are often drought-resistant, allowing them to survive long dry periods and hatch when water returns. This adaptation is crucial for their survival in unpredictable environments.

These crustaceans are filter feeders, using their appendages to strain small organic particles and algae from the water. They play an important role in freshwater ecosystems as a food source for fish and other aquatic animals. Conchostracans have a relatively simple body plan, with a segmented body and numerous pairs of appendages used for locomotion, feeding, and respiration. Their life cycle is generally short, with rapid development from egg to adult. Fossil conchostracans are known from the Devonian period, indicating a long evolutionary history. Despite their widespread distribution and ecological importance, conchostracans are often overlooked due to their small size and habitat.