Fig. 2.

Architecture of decapod nephrocytes in relation to phylogeny. Decapod branchial nephrocytes exhibit higher similarity to the eucoelomate epithelium-forming podocytes (a–a″) than Drosophila solitary nephrocytes (g–g″) in tissue organization (a–g), foot process formation style (a′–g′), and pattern of foot process arrangement (a″–g″). (b–b″, c–c″, d–d″) In prawn, lobster, and crayfish, nephrocytes are organized into a closed epithelial sac or an epithelioid and foot processes are formed by protrusion and are arranged in an intercellular interdigitating (ICI) pattern as podocytes (a′, a″). (e–e″, f–f″) In hermit and mitten crabs, nephrocytes are not organized into an epithelium and foot processes are formed by infolding as in Drosophila nephrocytes (g′). However, foot processes are arranged following an interdigitating pattern, i.e., autocellular interdigitating pattern (ACI)