The purpose of this guide is to provide a reference to assist biologists in the Central Appalachian region with identifying sex of live adult salamanders. However, sexing salamanders can be particularly difficult because secondary sex characters are often subtle or only visible during the breeding season, and guidance on species-specific sex determination is lacking from most field guides. Whether other plethodontids show similar variation among sexually dimorphic glands is another topic for future research.ĭocumenting the sex of individuals encountered during wildlife research and monitoring activities is important for understanding and tracking changes in populations. This indicates a difference in secretory product and function for the three glands and needs further investigation. Whereas the secretory vacuoles of mental glands are uniformly electron dense, those of caudal courtship glands are smaller (1.2–1.5 μm), oblong and biphasic, and vent glands have spherical biphasic secretory vacuoles (1.8–2.1 μm). Although all three glands show similarities in histology and histochemistry at the light microscopy level, they are dissimilar in ultrastructure.
#Hedonic glands skin
Two other sexually dimorphic skin glands, the caudal courtship gland and the cloacal vent gland, were previously examined from males in this sample of P. cinereus agrees with earlier descriptions for E. The ultrastructure of the mental gland of P. Mental glands from June and August contain only condensing vacuoles, and the cytoplasm is otherwise packed with stacks of rough endoplasmic reticulum. In these specimens, 6- to 8-μm electron-dense secretory vacuoles are found in the apical cytoplasm (October) or throughout the entire epithelial cells (April).
sperm in their Wolffian ducts) in October and April. The mental glands are most hypertrophied in males examined in mating condition (i.e. In this study, ultrastructure of the mental gland is described from seasonal samples of the eastern North American plethodontid Plethodon cinereus. A number of studies exist on the morphology of mental glands at the light microscopy level, but ultrastructural studies on the glands exist for only two species, Eurycea quadridigitata and Hydromantes italicus. These glands have been demonstrated to secrete pheromones that increase female receptivity to courtship and mating. Mental glands are sexually dimorphic glands found in the skin of the submandibular region in males of many species in the salamander family Plethodontidae. mississippi, caudal courtship glands are scattered among significantly larger granular glands and are similar in size to mucous glands. conanti, caudal courtship glands are similar in size to granular glands and larger than mucous glands. quadridigitata, active caudal courtship glands are larger than mucous and granular glands, but in D. Hypertrophied mental glands are larger than mucous or granular glands in all species, but relationships among caudal courtship glands and other skin glands vary among species. Morphological variation was observed across the three species studied in both clustering and relative size of the glands compared to neighbouring mucous and granular glands. Both mental and caudal courtship glands were observed to vary seasonally in gland diameter and histology according to the breeding season of each species. This study represents the first use of scanning electron microscopy to observe these glands. This study presents novel histological and fine structure data on mental glands and caudal courtship glands in Plethodon mississippi, Desmognathus conanti and Eurycea quadridigitata using both light microscopy and scanning electron microscopy. Salamanders in the family Plethodontidae exhibit a unique tail-straddle walk during courtship that can include the use of sexually dimorphic mental and caudal courtship glands.
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