Arctic Life/Arctic Animals/Invertebrates/Crustaceans

From Arctic Bioscan Wiki

Crustaceans

White, succulent flesh, smothered in butter; crustaceans like shrimp, lobsters, and crabs are famous the world over as an item of cuisine. Arctic crustaceans do not share the same appeal to diners, although one group of marine invertebrates, the amphipods, has featured in the diet of starving explorers. The shrimp fauna of arctic seas is very limited, and crabs are absent from the archipelago. However, there is an immense diversity of smaller crustaceans in polar waters.

Crustaceans possess the hardened covering that is characteristic of all arthropods. Some of the larger species in this group, such as lobsters, have calcium in their shell, which provides additional strength. Unlike the other two divisions of arthropods – the spiders and mites, and the insects – crustaceans are almost entirely aquatic, with the majority of species living in marine environments. The group is characterized by two pairs of antennae, and segmented bodies, with a variable number of appendages (legs) that accomplish a wide range of tasks. Swimming or crawling, filter feeding or grasping prey, transferring sperm or brooding the young, appendages have different functions. The shape of the body also varies drastically with lifestyle. Many crustaceans are planktonic, floating or swimming in water currents, while others are benthic, staying put on the bottom. Others are parasites, clinging to fish or other organisms, while barnacles attach themselves to rocks or other objects permanently. When most crustaceans hatch out of their eggs, they are small, rounded larvae – known as nauplii – with three pairs of appendages and one eye.

Freshwater invertebrate species have spread throughout the Arctic since the last glaciation, about 11,000 years ago. Some of the Arctic's most common freshwater crustaceans have close relatives that live in marine waters. These species occupied the seawaters that surrounded the edge of the glacier as it retreated. When the islands rebounded, gradually lifting up out of the sea, some animals became stranded in ponds and lakes, and adapted to the freshwater habitat. All told, there are over one hundred species of freshwater crustaceans in the Arctic, and many times more species occupying marine waters of the region.

Northern Crustaceans

There are 14 major groups of crustaceans present in the Arctic, and each is more interesting than the last. We have compiled a list of Arctic mammals that you would most likely encounter in the North. Please click below to learn more about each group or class.