Resident spawning of Japanese smelt, Hypomesus nipponensis, along gravel shorelines in Lake Nojiri, Central Japan
| Autor: | Miles I. Peterson, Hideyuki Ida, Satoshi Kitano |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
education.field_of_study Ecology biology urogenital system 010604 marine biology & hydrobiology fungi Population Hypomesus nipponensis Management Monitoring Policy and Law biology.organism_classification 010603 evolutionary biology 01 natural sciences Substrate (marine biology) Fish ladder Water level Fishery Stocking Habitat Environmental science Smelt education reproductive and urinary physiology Nature and Landscape Conservation |
| Zdroj: | Landscape and Ecological Engineering. 17:547-554 |
| ISSN: | 1860-188X 1860-1871 |
| Popis: | In Lake Nojiri, the Japanese smelt, Hypomesus nipponensis McAllister, 1963, population has been thought to be maintained by artificial spawning, and stocking efforts as natural spawning in in-flowing streams is unlikely due to the lack of inflowing stream habitat. In this study, novel resident Japanese smelt spawning was observed along the lakeshore in shallow areas with clean gravel and flow. Spawning occurred at night during early March to mid-April and eggs, confirmed on gravel substrate, progressed to the eyed state in 5–6 weeks. Although natural spawning was observed, the ratio of eggs that progressed to the eyed stage was minimal, possibly due to thick algae cover in areas with low flow velocity. Therefore, resident Japanese smelt spawning along the lake shoreline is physically possible and potentially contributes to the overall population in Lake Nojiri, but in-lake spawning alone presumably is not a biologically viable method for population sustainability due to low survival rates and egg density at present. Environmental improvements such as construction of fish ladders to suitable in-flowing spawning habitat, introduction of clean gravel to shorelines, and water level management adjusted to the smelt spawning run would contribute to higher recruitment by natural smelt reproduction, and consequently enhance the smelt production in Lake Nojiri. |
| Databáze: | OpenAIRE |
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