First Investigations of Benthic Soft-Walled Foraminifera and Gromiids (Protozoa) in the northwestern Sea of Japan.

The taxonomic and quantitative composition of the meiobenthos, with an emphasis on foraminifera and gromiids were studied on the coast of Primorsky krai, northwestern part of the Sea of Japan, at water depths of 0.3–86.0 m. The Protozoa were evaluated for the first time in this region as a component of the meiobenthic communities. The protozoa are represented by four morpho-ecological groups: Ciliophora (free-moving and epibionts), both hard-shelled and soft-walled Foraminifera, and Cercozoa (class Gromiidea). The total abundance of the meiobenthos varied from 32 500 to 2 107 500 ind./m². The presence of Protozoa was extremely variable. They were completely absent (station 62) and reached a maximum 155 000 ind./m² (station 42). Among the protozoans, soft-walled foraminifers (SWF) and gromiids (GR) dominated. GRs accounted for up to 51–85% of the abundance of the total protozoa at some stations in Peter the Great Bay. At other stations, SWFs prevailed and reached 93–100% of the total protozoa. The most numerous hard-shelled foraminifers (HSF) and ciliates (CL) were obtained in the Vladimir Bay and at individual stations off the eastern coast of Primorsky krai. Brief descriptions with illustrations are given for 45 representatives of the SWF belonging to the families Allogromiidae and Saccamminidae, of which 22 of them are identified to the species or genus level, and 23 morphotypes are identified to the family level. The gromiid fauna is represented by six morphotypes. [ABSTRACT FROM AUTHOR]