- 著者
-
伊牟田 直輝
中村 薫
平田 八郎
- 出版者
- 鹿児島大学
- 雑誌
- 鹿児島大学水産学部紀要 (ISSN:0453087X)
- 巻号頁・発行日
- vol.43, no.1, pp.p61-67, 1994-12
To examine artificial pellets as a substitute for feed of the larval firefly Luciola picticollis, feeding experiments were conducted with commercial prawn pellets for 190 days. About 100 larvae just after hatching were accommodated into a 5l polyurethane stock tank provided with pebbles, aeration and filtration apparatus, and fed with living snails Semisulcospira libertina. Before beginning of feeding experiments, 20 individuals as the control and 10 individuals as the first experiment were sampled from the stock and transferred into each 1l tank provided with aeration and only a stone as a shelter. They were fed with the snail meat or pellets. After 60 days, two groups of 10 individuals were added to the feeding experiment as the second and third. Mean plus S.D. of the control body length was 17.7±6.5mm in 190 days. That of the first experiment was 4.6±0.7mm in 80 days. That of the second or third experiment was 10.3±3.4mm or 7.4±1.8mm each in 130 days. Means plus S.D. of the body weight at 2, 3, 4, 5, 6, and 7 instars of the control were 3.1±0.1mg, 6.9±0.1mg, 11.6±1.0mg, 44.7±1.4mg, 74.3±17.8mg, and 196.8±74.7mg. Those at 2, 3, 4, and 5 instars of the experimental group were 2.1±0.3mg, 4.2±0.8mg, 6.5±0.5mg, and 19.8±6.2mg. The pellets were able to maintain growth of firefly larvae, though they were not nutritionally excellent. From the binocular observation of larval feeding on pellets, maxillae were found to elongate and function in like manner of a drill.1)カワニナの代替にクルマエビ用の配合餌料を用い,ゲンジボタル幼虫の餌料飼育試験を行なった。 2)カワニナ餌区(対照区)を1つ,配合餌料区(実験区)を3つ設定し,190日間飼育実験した。実験期間中水温は,12°Cから27°Cの範囲で変化した。 3)平均体長±標準偏差は,対照区において190日目で17.7±6.5mm,実験1区は80日目で4.6±0.7mm,実験2区と実験3区は,各130日目で10.3±3.4mmと7.4±1.8mmであり,カワニナの方が配合餌料より早い伸びを示した。しかし生存率は逆に後者の方が良かった。 4)平均体重±標準偏差は各齢毎の測定で,対照区;2齢3.1±0.1mg,3齢6.9±0.1mg,4齢11.6±1.0mg,5齢44.7±1.4mg,6齢74.3±17.8mg,7齢196.8±74.7mg,実験区;2齢2.1±0.3mg,3齢4.2±0.8mg,4齢6.5±0.5mg,5齢19.8±6.2mg,となり齢数が加わるにつれて増加した。同時に体重の個体差も増加が示された。 5)配合餌料はカワニナ餌より成長効果が劣った。しかし,配合餌料でも摂餌は持続し成長も少なからず示されたこと,また生存率はカワニナ餌よりも良かったこと,等から本配合餌料は代用餌としての可能性を残す。 6)ゲンジボタル幼虫の摂餌行動上,従来不明であった小腮の役割に関して新知見を得た。