(A) Shell of Vittina turrita. (B–E) SEM images of one radula from control group. B. Image of outermost part of radula (wear and digestive zone; arrow points in direction of increasing wear) with definition of the anatomical directions (medial, lateral, anterior, posterior) and radular axes (transversal and longitudinal axis). (C) Central teeth (red) and lateral teeth I (green). (D–E) Lateral tooth II (purple) and inner 15 marginal teeth (yellow) of degenerative zone. CT = central tooth, DZ = degenerative zone, LTI = lateral tooth I, LTII = lateral tooth II, MT = marginal teeth, TH = thickening of membrane/interlocking teeth. Scale bars: A = 30 mm, B = 250 μm, C–E: 60 μm.