Food Spectra of Snow Crabs (Chionoecetes opilio (O. Fabricius, 1788) (Decapoda, Oregoniidae), Non-Indigenous Species of the Kara Sea

The food spectra of a local group of snow crabs Chionoecetes opilio was studied by the analysis of stomach content. This abundant group of crabs settled in the vicinity of the Blagopoluchiya Bay (the Kara Sea coast of the Novaya Zemlya archipelago) in 2013–2014. By September 2018, the mass cohort reached the VI instar, the average carapace width of males was 28 mm and of females, 27 mm. The stomachs of more than 60% of the crabs were filled with food by 50% or more. Snow crabs behave as non-selective epibenthic feeders, consuming both plant and animal food (exclusively invertebrates), with some degree of cannibalism. The highest frequency of occurrence was observed for brittle stars (68.9%, which also accounted for more than a third of the volume of the virtual food lump), detritus (63.8%), and plant residues (60.7%), followed by bivalves and polychaetes. The average number of prey per stomach (Froerman coefficient) was 2.86, which was typical for gathering predators. Snow crabs used almost all of the abundant and available macrobenthos resources as food items. Snow crabs from open shelf areas do not usually eat macrophytes and detritus (possibly originating partially from macrophytes). These characteristics are peculiarities of the feeding of snow crabs in deep fjords, abundant on the eastern coast of the Novaya Zemlya archipelago.