Manabu Kume

Estuarine and coastal ecosystems are important habitats for many fish species. Large-scale patterns of estuarine and coastal fish communities can be affected by geographical factors, such as water temperature and latitude, that limit or allow fish dispersal, and/or by environmental factors that select locally adapted species. Furthermore, increased human activity has also altered fish diversity by modifying estuarine/coastal environments. Here, we used environmental DNA metabarcoding to study a

When two closely related species migrate to divergent spawning sites, divergent use of spawning habitats can directly reduce heterospecific mating. Furthermore, adaptations to divergent spawning habitats can promote speciation as a by-product of ecological divergence. Here, we investigated habitat isolation and ecological divergence between two anadromous forms of threespine stickleback (Gasterosteus aculeatus), the Japan Sea and Pacific Ocean forms. In several coastal regions of eastern Hokkaid

Although the Japanese eel Anguilla japonica is a commercially important species, its habitat use is not well understood during its life stages in the river. In this study, we investigated the longitudinal distribution and microhabitat use of young Japanese eels (<200 mm in total length [TL], which correspond to elver and early yellow stages) using 180 quadrates (1 m × 1 m) in six stations in a small river (approximately 11.5 km long, 3.0–25.0 m wide) that flows through paddy areas in Fukushima P

On March 11, 2011, a large earthquake occurred, causing a tsunami which struck the Pacific coast of northeast Japan. We investigated the ecological and genetic effects of the large tsunami on the threespine stickleback (genus Gasterosteus) populations in Otsuchi Town, which was one of the most severely damaged areas after the tsunami. Our environmental surveys showed that spring water may have contributed to the habitat recovery. Morphological analysis of the stickleback before and after the tsu

Juveniles in the Japan Sea form of three-spined stickleback Gasterosteus aculeatus collected from a tidal pool in eastern Hokkaido Island, Japan, had a unimodal standard length (L(S)) frequency distribution in each period, ranging from 11.9 to 31.6 mm, and those of sea-run migrating individuals collected from the outlet of this tidal pool ranged from 17.0 to 36.0 mm, suggesting juveniles of this form would migrate towards the sea when they reached >17.0 mm. In general linear models (GLM) for tes

Although river-crossing structures can have a detrimental effect on the movement and distribution of anguillid eels (genus Anguilla), they have inhabited locations upstream of river-crossing structures in many rivers. However, the growth stage in which the eels start to climb river-crossing structures remains unclear. In this study, we directly observed, using infrared video camera systems, that the Japanese eel (Anguilla japonica) climbs a low-height vertical weir as a migratory barrier, confir

Manabu Kume (2011) Clutch and egg sizes of two migratory forms of the threespine stickleback Gasterosteus aculeatus in eastern Hokkaido, Japan. Zoological Studies 50(3): 309-314. Clutch and egg sizes were compared between the Japan Sea and Pacific Ocean forms of the threespine stickleback collected from the Bekanbeushi River in eastern Hokkaido, Japan. The Japan Sea form produced many small-sized eggs, whereas the Pacific Ocean form produced fewer large-sized eggs, suggesting the existence of a