In this paper we report the diversity of metchnikovellids discovered in two surveys at the silt littoral/sublittoral zone in vicinity of Marine Biological Station of St. Petersburg State University, Island Sredniy, Chupa Inlet, Kandalaksha Gulf of the White Sea performed in 1986-1987 and in 2009-2010. The list of metchnikovellid species that had been recorded for the locality includes: Metchnikovella hovassei, a parasite of the gregarine Lecudina sp. from the polychaete Allita (Nereis) virens; M. selenidii, a parasite of Selenidium sp. from Ophelia limacina; M. spiralis and M. incurvata from Polyrhabdina sp. from Pygospio elegans; and Amphiamblys capitellae from Ancora sagittata from Capitella capitata. Noteworthy, M. incurvata was never observed in the 1986-1987 survey. In 2009-2010 though, it became even more abundant than M. spiralis. Given the patchy distribution of metchnikovellids among gregarine and polychaete populations, M.incurvata might have been overlooked in 1986-1987 survey. Alternatively, th