HISTOLOGICAL STUDY OF SKIN STRUCTURE VARIATION ACROSS DIFFERENT BODY REGIONS OF FOUR-LINED TREE FROG IN SARAWAK (Polypedates leucomystax) AMPHIBIA: ANURA: RHACOPHORIDAE

The frog skin is essential for its respiration, to retain chemical toxins, osmoregulation, and protection. Each of the frogs’ skin glands has a specific function. Therefore, variations in skin traits in different body regions of frogs may be in response to their environmental adaptability. Tree frogs encounter the challenges posed by disruption of natural habitats. In order to our understanding of the function of glands and gland variations across distinct body regions, we examine skin structure in the Bornean Four-lined Frog, Polypedates leucomystax. Using Haematoxylin and Eosin staining techniques and a light microscope, the skin of selected adult frogs was investigated. The results revealed that the various body regions of P. leucomystax exhibited the same trait in terms of the layers of the epidermis and dermis within their skins. In the skin of P. leucomystax, three type of glands, namely mucous, serous, and seromucous glands, release their contents onto the epidermal surface via an intra-epithelial duct. The thickness of the epidermal layer and the distribution of glands differ between the dorsal and ventral areas, implying an underlying strategy of adaptation. The presence of seromucous glands is abundant in every part including dorsal and ventral for this species’ special adaptability. The observed patterns of serous, mucous, and seromucous gland distribution across distinct skin regions could potentially mirror the behaviours of this species within its natural habitat. These discoveries may aid in understanding how the skin structure fulfil the ecological needs of the species, particularly within the modified settings of fragmented environments.