@article{oai:nagasaki-u.repo.nii.ac.jp:00027505, author = {Manh Ha, Linh and Iguchi, Kei’ichiro}, issue = {3}, journal = {Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society}, month = {Jun}, note = {The present study describes a fish individual of Plecoglossus altivelis ryukyuensis with three pelvic fins collected from a hatchery-reared population in Amami-oshima Island, Japan. The additional pelvic fin had the same number of rays as the neighboring pelvic fins (eight fin rays), and its girdle was fused with that of the neighbor. The comparison of morphometric measurements and meristic counts of the abnormal specimen with those of the normal specimens revealed that this abnormality was not a syndrome when all other characteristics were in the expected ranges. The condition factor of abnormal fish was close to the ideal value, suggesting that this abnormality did not severely affect the activities of the fish under rearing conditions. Well-managed rearing conditions might contribute significantly to the survival and growth of abnormal fish. The cause of this abnormality is unclear, but the limited diversity in the genome of the subspecies is assumed to be a probable factor., Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society, 15(3), pp. 1302-1307; 2022}, pages = {1302--1307}, title = {An abnormal specimen of threatened Ryukyu-ayu (Plecoglossus altivelis ryukyuensis) with an additional pelvic fin}, volume = {15}, year = {2022} }