Dasids

Dasids are a family of marine invertebrates belonging to the order Pseudestheria. They are commonly known as clam shrimps or conchostracans. These small crustaceans are characterized by their bivalved carapace, which resembles that of a clam, hence their common name. The carapace encloses the majority of the animal's body, but the head, with its appendages, usually protrudes from the posterior opening.

Dasids are typically found in freshwater environments, inhabiting temporary ponds, ephemeral pools, and shallow lakes. They are particularly well-adapted to survive in habitats that experience periods of drought. Their eggs are remarkably resistant to desiccation and can remain dormant for extended periods, hatching only when favorable conditions, such as the presence of water, return. This ability to endure dry spells is a key factor in their distribution and survival.

The diet of dasids consists mainly of algae, detritus, and other small organic particles suspended in the water or found on the substrate. They are filter feeders, using their appendages to create currents that draw food particles towards their mouths. Their life cycle is often short, with rapid development and reproduction occurring during favorable wet periods.

While not as widely recognized as some other crustaceans, dasids play a role in freshwater ecosystems as a food source for fish and other aquatic organisms. Their presence and abundance can be indicators of the ecological health of temporary water bodies. Fossilized dasid carapaces are also important in paleontology, providing insights into past aquatic environments.