The mental gland of the plethodontid salamander Bolitoglossa nicefori was examined by macroscopic observation and light microscopy and compared with morphological descriptions of other species of Plethodontidae. The mental gland is an oval shaped pad which develops exclusively in reproductive males. It is composed of 255 to 710 simple glands of merocrine secretion arranged in a dorso-ventral disposition. The outlets of the glands are spindle-shaped or fusiform. Negative stain reaction for AB and PAS is consistent with results of the glandular components of mental glands from other Plethodontidae. Males of this species produce sperm continuously throughout the year: all examined adult males showed conspicuous mental glands. However, an evident and significant increase in the surface area of the mental gland pad, in the density of the glands, and in the number of tubular glands was observed in the males collected during the breeding season. At the histological level, a slight variation was observed among males in the height and diameter of the simple tubular glands, and significant variation was found in the diameter of the secretory granules. This variation may reflect the fact that, although males potentially can mate during all months of the year, females oviposit seasonally. During this defined season, the hypertrophy of the mental gland is the greatest.

Male and female plethodontid salamanders have specialized cloacal glands associated with the reproductive activity. The reproductive cycle in Bolitoglossa nicefori is characterized by males that are potentially reproductive throughout the year, and females that are reproductive only for a few months. To determine whether morphological and histochemical variation occur in cloacal structures related to reproductive activity, the cloacal region of male and female specimens of B. nicefori was studied in different stages of their annual reproductive cycle using light microscopy and compared with features reported in other plethodontid salamanders. The main anatomy and histology of the male and female cloacal regions of B. nicefori are similar to those of other salamanders; however, in comparison to other Bolitoglossa previously studied, B. nicefori has a relatively larger cloacal tube and a tubular rather than acinar spermatheca. As a common trait, the spermatheca has a common tube that diverges into two tubules, before branching into spermathecal tubules, horizontally arranged on frontal planes. The secretions of the spermathecal glands differed between reproductive and nonreproductive adult females. This secretory product consists of prevailing neutral carbohydrates that were related to the increase in ovarian follicular size during the breeding season. Sperm was found only in the spermatheca of reproductive periovulatory females, suggesting that the reproductive cycle involves a no long-term storage of sperm. Although males can produce sperm throughout the year, spermatophores, namely specialized structures involved in sperm transport, were found in their cloaca only during the breeding season. In these males, some of the cloaca-associated glands were seen to undergo change their secretory activity and their secretory products were related to spermatophore formation. Anat Rec, 294:349-362, 2011. V V C 2010 Wiley-Liss, Inc.