Heiluri

Heiluri, known as the Atlantic herring or Clupea harengus, is a species of small pelagic fish belonging to the family Clupeidae. Widely distributed in the temperate waters of the North Atlantic Ocean, it is an essential component of marine ecosystems and a significant target for commercial fishing.

Typically, heiluri grow to about 20 to 25 centimeters in length, although larger individuals may reach up to 30 centimeters. They possess a streamlined body adapted for efficient swimming and are characterized by their silvery coloration, which provides camouflage in the open water. Their diet mainly consists of plankton, including copepods and tiny crustaceans, which they filter using their gill rakers.

Heiluri are known for their schooling behavior, often forming large, dense groups that can encompass millions of individuals. This schooling offers protection from predators and enhances their efficiency in feeding and migration. During spawning seasons, usually from late winter to spring, females lay thousands of eggs on the seabed or submerged vegetation. The larvae hatch after approximately two weeks and quickly grow, contributing to the species' rapid reproductive cycle.

The Atlantic herring plays a vital role in commercial fisheries across Europe and North America, providing a source of food for humans and livestock and serving as prey for a variety of larger predatory fish, seabirds, and marine mammals. Due to overfishing and habitat shifts driven by climate change, some populations have experienced declines, leading to management measures aimed at sustainable harvesting.

Overall, heiluri is an ecologically and economically important species, highlighting its significance in marine biodiversity and global food security.