FIG. 5 in The Nuptial Pads of Melanophryniscus (Anura: Bufonidae), with the Unexpected Occurrence of Nuptial-Pad-Like Structures in Females of Two Species

FIG. 5. Histochemistry of nuptial pads of Melanophryniscus macrogranulosus. (A) Male (UFRGS 6327), specialized mucous gland (SMG) positively stained with PAS + AB on the distal portion of each secretory cell. (B) Male (UFRGS 6327), SMG positively stained with AB. (C) Males (UFRGS 6586) present keratin ornamentation on top of papillae (white arrows). Gland ducts (d) open between papillae. Section stained with hematoxylin and eosin; SMG granules positively stained with eosin. (D) Detail of a SMG in male (UFRGS 6448), showing duct (d), formed by a thin layer of keratinized cells that cross the epidermis and opening between papillae; intermediate region (black arrow) and the secretory cells, filled with granules that positively stained with fuchsine but not with toluidine blue. Scale bars: (A,B) 100 µm; (C,D) 50 µm.