Valtionpään

Valtionpään (*Pleurotomaria arctica*) is a species of sea snail, a marine gastropod mollusk in the family Pleurotomariidae. It is commonly known as the Arctic topshell or northern topshell, and is native to the cold waters of the North Atlantic Ocean, particularly around the Arctic and subarctic regions. This species is often found attached to rocks, seaweed, or other hard substrates in shallow to moderate depths, typically between 10 and 100 meters.

The shell of *Pleurotomaria arctica* is distinctive, characterized by its smooth, glossy surface and conical shape. It is usually light brown to grayish in color, often with darker spiral bands or markings. The shell can reach up to 5 centimeters in length, though sizes vary depending on age and environmental conditions. Like other pleurotomariids, it lacks an operculum, a hard structure that typically seals the shell’s opening in many gastropods.

Valtionpään plays a role in its ecosystem as both predator and prey. It feeds primarily on algae and other small organisms, using its radula—a specialized feeding organ—to scrape and rasp surfaces. In turn, it serves as food for various marine species, including fish and other mollusks. Due to its cold-water habitat, it is sensitive to environmental changes, such as warming ocean temperatures and ocean acidification, which may impact its distribution and survival.

This species is not widely studied compared to more commercially or ecologically significant mollusks, but it contributes to the biodiversity of its marine environment. Conservation efforts are generally not targeted specifically at *Pleurotomaria arctica*, though broader marine protection initiatives may indirectly benefit its populations. Its presence is often used as an indicator of healthy, undisturbed coastal ecosystems in Arctic and subarctic regions.