äyriäislajit

Äyriäislajit, scientifically known as Crustacea, are a large and diverse subphylum of arthropods. They are characterized by a hard exoskeleton, segmented bodies, and jointed appendages. This group includes familiar animals such as crabs, lobsters, shrimp, and barnacles, as well as less commonly known species like copepods and krill. Äyriäislajit inhabit virtually all aquatic environments, from the deepest oceans to freshwater lakes and rivers, and some even exist in terrestrial habitats.

The diversity within Äyriäislajit is immense, with over 67,000 described species. Their body plans vary significantly, but most possess a head and a thorax, often fused into a cephalothorax, and an abdomen. Respiration typically occurs through gills, though terrestrial species may have adaptations for air breathing. Their diet is equally varied, ranging from filter-feeding to predation and scavenging. Many äyriäislajit play crucial roles in their ecosystems, serving as both prey and predators, and contributing to nutrient cycling. Some species are economically important, forming the basis of important fisheries worldwide.