Gruberella flavescens (Gruber, 1889), a multinucleate lobose marine amoeba (Gymnamoebia)

Abstract

A multinucleate, monopodial, lobose amoeba from a Cornish rock pool was identified as Amoeba flavescens Gruber, 1889, originally described from the Mediterranean. It is the type species of a genus Gruberella. Although its locomotive form and activity resemble those of the uninucleate Vahlkampfiidae and its Golgi system, like that of the vahlkampfiids, is not organized into dictyosomes, its mitotic pattern differs from that of the vahlkampfiids. The presence of mitochondria and other characters distinguish it from Pelomyxa. The only other similar marine amoeba is Hyperamoeba fallax Seravin & Goodkov, 1982, from the Far East. The process of ‘paracopulation’ reported for H. fallax was not observed in the Cornish isolates. Pending more evidence of familial relationships, Gruberella remains incertae sedis within the suborder Gymnamoebia Haeckel, 1862.