The Kamchatka crab is one of the largest representatives of crustaceans. It was first described by the naturalist Wilhelm Gottlieb Tilesius von Tilenau, a member of the first Russian circumnavigation expedition on the sloop “Nadezhda”. His article “On the Crabs of Kamchatka, Woodlice and Entomostraca” was published in French in a publication of the Imperial Academy of Sciences in St. Petersburg in 1815.
Wilhelm Tilesius described a female crab, which was given to him by local fishermen on July 18, 1804, when the sloop “Nadezhda” was in the waters of Avacha Bay. The crab species new to science was named the Kamchatka crab — Paralithodes camtschatica (Tilesius), and a hundred years later, it became the most important species of crab fishery in the Far East.
Later, scientists found out that the average weight of a male Kamchatka crab exceeds two kilograms, the width of its shell is about 16 centimeters, and the leg span is about one meter. At the same time, the weight of the largest males can reach 7 kilograms. Female Kamchatka crabs are smaller, with a maximum weight of five kilograms.
The shell as well as the legs of the Kamchatka crab are red and brown above and yellowish-white below. Their lateral surfaces have large purple spots. The habitat of Paralithodes camtschatica (Tilesius) is very extensive. In addition to Kamchatka, it can be found near Sakhalin, the Shantar and Kuril Islands, in the Sea of Okhotsk and the Bering Sea, the northern part of the Sea of Japan, and Alaska.
In the 1960s and 1970s, the high value of the Kamchatka crab prompted its artificial introduction to the Barents Sea. In the new territory, the crab established stable populations, spreading along the coast of Norway and in the Svalbard archipelago.
Kamchatka crabs migrate
actively on a large scale. In a year, they travel over 100 kilometers along the
bottom. Unlike true crabs, they move using four rather than five pairs of
limbs. The direction of movement is zigzag to the side. Every year
representatives of the species repeat the same route, driven by seasonal
changes in water temperature, availability of food, and breeding instinct.