A Description of the Skin Glands and Cloacal Morphology of the Plethodontid Salamander Karsenia koreana
The skin glands and cloacal morphology of the Korean crevice salamander, Karsenia koreana, were similar to those of other plethodontids. The skin contained mucous, granular, and modified granular glands in varying frequencies and sizes. Males had sexually dimorphic glands in the skin of the chin (mental glands) and the dorsal tail base (caudal courtship glands). On the ventral surface of the tail base, modified granular glands were sexually dimorphic in size, with male glands larger than those in females. The cloacal glands in males, as in other plethodontids, consisted of four eosinophilic gland clusters (dorsal pelvic glands, lateral pelvic glands, caudal pelvic glands, and vent glands) and three basophilic glands (anterior ventral glands, posterior ventral glands, and Kingsbury's glands). In females, the only cloacal gland was the spermatheca, which, as in other plethodontids, was a compound tubulo-alveolar gland in the roof of the cloaca.
The skin of Karsenia koreana contains mucous, granular, modified granular, and sexually dimorphic glands. (A) Transverse section through the dorsal tail base region in a sexually mature male shows the PAS+ caudal courtship glands with surrounding granular glands (quad stain). (B) Transverse section through the postcloacal region of a male shows a modified granular gland in which the cells lining the lumina are not distinct (though nuclei are) and the lumina are generally full of secretory product (quad stain). Smaller typical granular glands also occur. (C) Transverse section through the ventral region of a female (quad stain). Ccg, caudal courtship gland; Ep, epidermis; Gg, granular gland; Mg, mucous gland; Mgg, modified granular gland; Sc, stratum compactum.
In males (A) the mental glands of Karsenia koreana cluster into a pad that is externally observable, as shown by the outline. (B) Transverse section through a group of mental glands showing PAS+ secretion at apices of the columnar epithelial cells (quad stain). (C) Females have modified granular glands in the dermis of the lower jaw, but they are smaller than the mental glands of males and not clustered (quad stain). Ep, epidermis; Mg, mucous gland; Mgg, modified granular gland; Mng, mental gland.
Transverse sections through cloacal fragments of male Karsenia koreana from anterior (A) to posterior (F; hematoxylin-eosin). (A) First specimen, probably cloacal tube. (B) Same specimen, anterior cloacal chamber. (C–F) Second specimen, sections proceeding caudally through the cloacal chamber. Ad, anterior depression; Av, anterior ventral glands; Cc, cloacal chamber; Cp, caudal pelvic glands; Dp, dorsal pelvic glands; Kg, Kingsbury's glands; Lp, lateral pelvic glands; Lr, lateral recess; Pv, posterior ventral glands; Sp, sperm; Vg, vent glands.
Transverse sections through cloacal fragments of a female Karsenia koreana, from anterior (A) to posterior (D; hematoxylin-eosin). Note that a dorsal portion of the right cloacal sheath is detached from the remaining tissue. (A) Cloacal tube. (B–D) Sections proceeding caudally through the cloacal chamber. Cc, cloacal chamber; Cot, common tube; Ct, cloacal tube; St, spermathecal tubules.
Transverse sections through distal spermathecal bulbs of a female lacking stored sperm (A) and a specimen containing stored sperm (B). Ac, apical cytoplasm; Fb, fibroblasts; Lu, lumen; Nu, nuclei; Sp, sperm; Va, vacuolated space.
Contributor Notes
Associate Editor: C. Beachy.