@article{oai:kindai.repo.nii.ac.jp:00005114,
 author = {原田,  輝雄 and 宮下,  盛 and 横山,  達雄},
 issue = {12},
 journal = {近畿大学農学部紀要, Memoirs of the Faculty of Agriculture of Kinki University},
 month = {Jan},
 note = {[Author abstract]The experiments of egg obtaining and artificial hatching in reared spotted parrot fish, Oplegnathus punctatus have been carried out at Shirahama Fisheries Laboratory, Kinki University, in Wakayama Prefecture. The experimented juveniles have been captured every year since 1963 near the coast of Kii Peninsular and fed with small frozen fish. These fish grow faster than the Japanese parrot fish, Oplegnathus fasciatus, and natural spawning was observed for the first time in 1970 and then continuously every year except 1976. To obtain eggs the stripping method has been applied since 1970. The spawning season extends from May to June when the water temperature ranged from 20 to 27℃. The total length of the fish matured at the age of 6 to 9 ranged from 42.6 to 50.8 cm. The eggs obtained by stripping measured 1.00 to 1.15 mm in diameter, but 1.01 to 1.20 mm in those obtained by natural spawning. The fertilized eggs are buoyant, spherical in shape, and hatch out 30 to 35 hours after fertilization at the water temperature from 22.2 to 22.6℃. The effects of temperature and specific gravity of sea water on hatching were observed. More than 80% of larvae hatched out were normal when the incubator was kept at 20 to 24℃, but no normal larva was produced under 16℃ or above 30℃; the specific gravity (a15) of sea water was maintained at 25.1 to 25.3 throughout the experiments. More than 78% of larvae hatched out were normal in the sea water of the specific gravity of 20 to 32, but no normal larvae was found at the specific gravity under 15, the water temperature was maintained at 21.4 to 23.7℃ throughout these observations.[著者抄録]1.1963年から1978年まで毎年紀伊半島沿岸で採補したイシガキダイの稚魚を白浜実験場で飼いつけて親魚まで黄成し,採卵と人工ふ化の実験を行なった。 2.イシガキダイの稚魚を田辺湾に設置した網いけすに収容し,小魚を餌料として飼育したところ,6年後には全長40cm以上,体重2,000g以上に成長し,6～9年魚から卵を採取し,人工ふ化することができた。 3.採卵は,1970年から1978年までの間に搾出法と自然産卵法とを試み,いずれも卵が採取されたが,自然産卵法の方が,容易に多量の卵を採取することができた。 4.産卵は5～6月,水温22～24℃を中心に,20～27℃の間で行なわれた。卵は直径1.0～1.2mmの浮性卵で,水温22.2～22.6℃では受精後30～35時間でふ化した。 5.水温がふ化に及ぼす影響を調べる実験の結果,正常な仔魚がふ化した水温は18～29℃であったが,80%以上の高率で正常な仔魚がふ化した水温の範囲は20～24℃であった。 6.海水の比重がふ化に及ぼす影響を調べる実験の結果,良質卵を用いた実験では,正常な仔魚がふ化した比重(σ_15>)は16.0～40.0であり、78%以上の効率でふ化仔魚が得られた比重の範囲は,20.0～32.0であったが,質がやや劣る卵での実験と総合すると,ふ化の最適比重は22.0～28.0であると考えられる。, application/pdf},
 pages = {43--49},
 title = {養成イシガキダイからの採卵・人口ふ化―特にふ化に及ぼす水温および比重の影響―},
 year = {1979},
 yomi = {ハラダ, テルオ and ミヤシタ, シゲル and ヨコヤマ, タツオ}
}