The multicellular structure formed by Dictyostelium under starvation is called:
Starved amoebae chemotax toward periodic cAMP waves emitted by aggregation centers, forming streams that converge into a mound. The mound elongates into a motile grex or slug containing up to one hundred thousand cells migrating as coherent unit. Plasmodium refers to unrelated myxomycetes with multinucleate masses, while zygospore and fruiting cluster are fungal terminology. Grex stage demonstrates division of labor without fusion, prespore and prestalk patterning, and coordinated phototactic movement. Ultimately this structure enables culmination into fruiting bodies, representing true multic
Ref: Gilbert, Developmental Biology, 12th ed., Chapter 22: Grex, slug migration and culmination mechanisms.