2017 Volume 64 Issue 2 Pages 145-156
Spring macroalgal beds, characterized by the occurrence of subtropical Sargassum species and short vegetation periods during spring, occur off western Kyushu and on the Pacific side of Shikoku, Japan. However, the fish assemblages of such macroalgal beds are poorly known. Fish censuses conducted by divers over a spring macroalgal bed and adjacent comparatively barren ground off Misaki, western Kyushu, from June 2014 to May 2015, noted luxuriant macroalgal stands from March to June in the former, whereas macroalgae were sparse from March to May in the barren area. Forty fish species (22 families) and 39 species (23 families) were recorded in the macroalgal bed and barren area, respectively, with similar mean numbers of species and individuals. In both areas, Halichoeres tenuispinis, Istigobius campbelli, Pseudolabrus sieboldi, Stethojulis interrupta terina and Pomacentrus coelestis occurred abundantly in all months surveyed. As the luxuriant macroalgal stands were seasonal, only fish species which could inhabit both vegetated and unvegetated habitats could persist yearlong within the area of the macroalgal bed. Two species, Apogon notatus and Chaenogobius gulosus, were seasonal inhabitants of both areas, the density of A. notatus tending to be higher in the macroalgal bed in June. C. gulosus occurred in the macroalgal bed and around sparsely distributed macroalgae in the barren area in March and April. Spring macroalgal beds may be an important habitat for seasonal fish species residents.
