Emergence behavior of a tide pool fish Praealticus tanegasimae (Teleostei; Blenniidae) on subtropical reefs

Abstract

Praealticus tanegasimae is a rockpool blenny that occurs around the higher edge of the intertidal zone in subtropical waters of the western Pacific. Terrestrial emergence from tide pools was confirmed in the blenny during daytime low tide periods on Kuchierabu-jima Island, southern Japan. They stayed in the pools, putting their heads above the water surface, and then jumped out with a tail flip. The duration for each terrestrial emergence ranged from 4 to 665 s (median 31 s), during which they never showed reproductive-related behaviors or active feeding behavior on land. The emergence behavior was often followed by hopping toward neighboring pools, and suggested that the goal of the behavior was to change pools for escape from unfavorable water conditions.