A Sexual size difference and microhabitat use of Amolops ricketti group (Anura, Ranidae) in Bach Ma national park, Thua Thien Hue province, Vietnam

Abstract

Amolops ricketti (group) is a species with nutritional and medicinal value. However, little is known about sexual size dimorphism (SSD), microhabitat use, and the mode of action of this species. We observed the behavior of this species in the field at Bach Ma National Park, combined with analyzing morphological characteristics in the laboratory. Based on 97 adult Rock Frog samples (44 males and 53 females), assessments and comparisons of morphological measurements and calculations of the SSD index were performed. The results showed that the average trunk length (SVL) of adult females was longer than that of adult males, with an SSD index of 0.23. This species lives in fast-flowing stream water, also known as torrential environments, with microhabitats mainly on high-slope rocks dominating (52.58%), followed by rocks with low-slope (34.02%). This species used the highest proportion of time for lying and waiting activities (77.78%). The mode of activity of this species is more suitable for the sit-and-wait model than the wide forager model. Some environmental, physical, and chemical indicators in the species' living area were also surveyed in this study.