Received: 15-01-2024 / Accepted: 12-04-2024
Showing amphibious features, mudskippers have been used as model species to gain understanding of the water-to-land transition of vertebrates. This study aimed to elucidate the relationship between terrestrial degrees and the utilization of pectoral fin-based locomotion and their morphology as well. The locomotor behavior, the aspect ratio of the fin, and the muscle ratio of three mudskippers and one goby were investigated. Results show that terrestrialization gradually increased in mudskippers, from Oxuderces nexipinnisto Scartelaos histophorusand Periophthalmodonseptemradiatus. Oxuderces nexipinnisand S. histophorusused the pectoral fins for crutching in aquatic, semi-aquatic, and terrestrial environments. They also employed the pectoral fins for waterskiing which is first reported for mudskippers in this study. In Pn. septemradiatus, the pectoral fins were mainly used for crutching on land (57.73%) and moistening (30.08%). The time proportion of crutching in terrestrial environment was high in species with higher terrestrialization. The aspect ratio of the pectoral fin and muscle ratio was correlated with terrestrial degrees.