Ammonia beccarii and Ammonia tepida (Foraminifera): morphofunctional arguments for their distinction

New observations from Yeu Island and the Bay of Bourgneuf on the Atlantic coast of France show that Ammonia beccarii s.s. and Ammonia tepida have different morphofunctional adaptations to their habitats and environments. Adult A. beccarii s.s. may be epiphytic, living on the calcareous alga Corallina officinalis or on the red alga Gigartina acicularis along rocky shores, while A. tepida is endopelic, living in sediments of brackish environments. Rapid 3-D emission of pseudopodia from interlocular spaces on both umbilical and spiral sides of adult A. beccarii s.s. can support its test within the seaweed framework. This behaviour is characteristic of phytal species. Thus, it appears that the major difference between A. beccarii s.s. and A. tepida is the presence of large interlocular spaces on spiral side of the former, corresponding to a potential morphofunctional adaptation to the epiphytic mode of life. We believe that these observations could help to solve the long-lasting A. beccarii problems of specific distinction.