Benthic foraminifera and the polychaete Sabellaria alveolata (Linnaeus, 1767) on the intertidal rocky shore at Ceinewydd, Ceredigion, Wales, UK

Abstract

Abstract Interactions between foraminifera and macrofauna have been little studied, especially on rocky coasts. This paper examines (a) the foraminiferal tests captured from suspension by the polychaete Sabellaria alveolata in an intertidal area on a rocky shore, and (b) the foraminifera living on those S. alveolata colonies. The rocky coast at Ceinewydd (Ballantine Exposure Scale 6) supports patchy colonies of S. alveolata ~1\u202fcm thick. We collected ~10\u202fcm2 areas to form three Sample Sets of four replicates each at low tide. Two Sample Sets came from a 1\u202fm2 lower shore rock-pool, Sample Set 1 being taken above water and Set 2 below water. Sample Set 3 was collected from a middle shore cobble. Four replicates were taken for each Set. The replicates were disaggregated, soaked in a rose Bengal solution and dried. The residues (106–2000\u202fμm, 7–9\u202fg aliquots) were picked clean of foraminifera. The total (live +dead) assemblage comprised Ammonia batava (53.6%), with lesser Asterigerinata mamilla (11.1%), Bulimina elongata (7.5%) and Elphidium selseyense (5.6%). There were no statistically significant (p