 |
|
|
||||
| NAS - Nonindigenous Aquatic Species |
Translate this page with 
Common Name: ayu
Synonyms and Other Names: (sweetfish, ko-ayu [land-locked form]).
Taxonomy: available through 
Identification: This species is characterized by the presence of an adipose fin; 10-12 dorsal rays; 9-17 anal rays; 5 or 6 branchiostegal rays; usually 59-64 vertebrae; no pelvic axillary process; and more than 300 pyloric caeca (Nelson 1984). Masuda et al. (1984) also gave characteristics. The species was formerly placed in its own family, Plecoglossidae (Nelson 1984).
Size: 30 cm.
Native Range:
Marine and freshwater, anadromous. Japan, Korea, Taiwan, and China (Nelson 1984).
Nonindigenous Occurrences: The ayu was stocked in California in 1961-1965 in Morris Lake, Mendocino County; Ruth Reservoir, Trinity County; and Eel River below Fortuna, Humboldt County (Hubbs et al. 1979; Dill and Cordone 1997). Earlier shipments of eggs to California did not survive and were not stocked (Dill and Cordone 1997). The ayu was introduced into Hawaii on the islands of Hawaii, Kauai, Maui, and Oahu (Maciolek 1984; Randall 1987; Mundy 2005).
Ecology: Adults live and spawn in freshwater. Larvae live in salt water and ascend streams when they reach 5-8 cm TL (Randall 1987).
Means of Introduction: With approval from the California Fish and Game Commission, about 3,845,000 eggs and fry were stocked in California waters from 1961 through 1965 (Dill and Cordone 1997). Relished as a food fish by Asians, Dill and Cordone (1997) stated that it was introduced to the state because it was felt to be a plant-eating fish expected to thrive in coastal streams considered marginal trout habitat. An estimated 250,000 fish were imported from Japan and intentionally stocked in Hawaii in 1925 and subsequent years, but failed to establish a reproducing population (Maciolek 1984).
Status: None of the fish in California survived (Shapovalov et al. 1981; Dill and Cordone 1997); it also failed to become established in Hawaii.
Impact of Introduction: Unknown.
Remarks: Dill and Cordone (1997) provided a detailed history of its introduction in California.
Courtenay, W. R., Jr., D. P. Jennings, and J. D. Williams. 1991. Appendix 2: exotic fishes. Pages 97-107 in Robins, C. R., R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R. N. Lea, and W. B. Scott. Common and scientific names of fishes from the United States and Canada, 5th edition. American Fisheries Society Special Publication 20. American Fisheries Society, Bethesda, MD.
Hubbs, C. L., W. I. Follett, and L. J. Dempster. 1979. List of the fishes of California. California Academy Science Occasional Papers 133. 51 pp.
Maciolek, J. A. 1984. Exotic fishes in Hawaii and other islands of Oceania. Pages 131-161 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology, and management of exotic fishes. The Johns Hopkins University Press, Baltimore, MD.
Masuda, H., K. Amaoka, C. Araga, T. Uyeno, and T. Yoshino, editors. 1984. The fishes of the Japanese Archipelago. Tokai University Press. Text: i-xxii + 437 pp.; atlas: pls. 1-370.
Nelson, J. S. 1994. Fishes of the world, 3rd edition. John Wiley and Sons, New York, NY.
Randall, J. E. 1987. Introductions of marine fishes to the Hawaiian Islands. Bulletin of Marine Science 41(2):490-502.
Other Resources:
FishBase Fact Sheet
Author: Pam Fuller and Leo Nico
Revision Date: 4/20/2006 Citation for this information:
Pam Fuller and Leo Nico. 2009. Plecoglossus altivelis. USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
<http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=797> Revision Date: 4/20/2006
| AccessibilityFOIAPrivacyPolicies and Notices | |
  |
|