Epibenthic, agglutinating foraminiferans in the Santa Catalina Basin and their response to disturbance

摘要: There are five common species of large (0.5–6 cm long) epibenthic, agglutinating foraminiferans in the Santa Catalina Basin (1200–1350 m). This paper describes their basic ecology and response to mound disturbance. Combined, attain mean densities 200–300 individuals per m2 protoplasm has an average biomass 199.5 mg m−2. Individual occur at ranging from 7 100 m−2, each a different population size structure. Protoplasm comprises <2% test volumes. Analysis excess 234Th revealed no indication particle sequestering within tests, acridine orange direct counts bacteria provided evidence microbial gardening or enhancement associated with tests. Twenty-five cent tests examined had metazoan associates; approximately half these were polychaetes. Experiments carried out investigate epibenthic foraminiferal assemblage disturbance large, biogenic mounds, feature on floor. Three branched forms, Pelosina cf. arborescens, P. cylindrica mud-walled astrorhizinid, most abundant background sediments, less natural mounds absent artificially-created exposed for 10.5 months. Two spherical species, Oryctoderma sp. present similar artificial (9.5–10.5 months old), undisturbed but attained largest sizes mounds. These two appear be opportunistic taxa that can colonize grow rapidly sediments. study suggests disturbance, this case by sediment builders, is important source spatial heterogeneity deep-water communities. Where occur, assemblages will experience disequilibrium dynamics.